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| -rw-r--r-- | docs/_static/images/vyos_1_4_nat66_simple.png | bin | 0 -> 21021 bytes | |||
| -rw-r--r-- | docs/conf.py | 4 | ||||
| -rw-r--r-- | docs/configuration/nat/index.rst | 731 | ||||
| -rw-r--r-- | docs/configuration/nat/nat44.rst | 733 | ||||
| -rw-r--r-- | docs/configuration/nat/nat66.rst | 127 | ||||
| -rw-r--r-- | docs/configuration/nat/nptv6.rst | 69 | ||||
| -rw-r--r-- | docs/configuration/protocols/bgp.rst | 23 | ||||
| -rw-r--r-- | docs/configuration/protocols/ospf.rst | 36 |
8 files changed, 909 insertions, 814 deletions
diff --git a/docs/_static/images/vyos_1_4_nat66_simple.png b/docs/_static/images/vyos_1_4_nat66_simple.png Binary files differnew file mode 100644 index 00000000..d7c54115 --- /dev/null +++ b/docs/_static/images/vyos_1_4_nat66_simple.png diff --git a/docs/conf.py b/docs/conf.py index 3d011ad5..594d6063 100644 --- a/docs/conf.py +++ b/docs/conf.py @@ -26,10 +26,10 @@ copyright = u'2021, VyOS maintainers and contributors' author = u'VyOS maintainers and contributors' # The short X.Y version -version = u'1.3' +version = u'1.4' # The full version, including alpha/beta/rc tags -release = u'1.3.x (equuleus)' +release = u'1.4.x (sagitta)' # -- General configuration --------------------------------------------------- diff --git a/docs/configuration/nat/index.rst b/docs/configuration/nat/index.rst index f0f5bd6a..90275226 100644 --- a/docs/configuration/nat/index.rst +++ b/docs/configuration/nat/index.rst @@ -8,732 +8,5 @@ NAT :maxdepth: 1 :includehidden: - nptv6 - -:abbr:`NAT (Network Address Translation)` is a common method of -remapping one IP address space into another by modifying network address -information in the IP header of packets while they are in transit across -a traffic routing device. The technique was originally used as a -shortcut to avoid the need to readdress every host when a network was -moved. It has become a popular and essential tool in conserving global -address space in the face of IPv4 address exhaustion. One -Internet-routable IP address of a NAT gateway can be used for an entire -private network. - -IP masquerading is a technique that hides an entire IP address space, -usually consisting of private IP addresses, behind a single IP address -in another, usually public address space. The hidden addresses are -changed into a single (public) IP address as the source address of the -outgoing IP packets so they appear as originating not from the hidden -host but from the routing device itself. Because of the popularity of -this technique to conserve IPv4 address space, the term NAT has become -virtually synonymous with IP masquerading. - -As network address translation modifies the IP address information in -packets, NAT implementations may vary in their specific behavior in -various addressing cases and their effect on network traffic. The -specifics of NAT behavior are not commonly documented by vendors of -equipment containing NAT implementations. - -The computers on an internal network can use any of the addresses set -aside by the :abbr:`IANA (Internet Assigned Numbers Authority)` for -private addressing (see :rfc:`1918`). These reserved IP addresses are -not in use on the Internet, so an external machine will not directly -route to them. The following addresses are reserved for private use: - -* 10.0.0.0 to 10.255.255.255 (CIDR: 10.0.0.0/8) -* 172.16.0.0 to 172.31.255.255 (CIDR: 172.16.0.0/12) -* 192.168.0.0 to 192.168.255.255 (CIDR: 192.168.0.0/16) - - -If an ISP deploys a :abbr:`CGN (Carrier-grade NAT)`, and uses -:rfc:`1918` address space to number customer gateways, the risk of -address collision, and therefore routing failures, arises when the -customer network already uses an :rfc:`1918` address space. - -This prompted some ISPs to develop a policy within the :abbr:`ARIN -(American Registry for Internet Numbers)` to allocate new private -address space for CGNs, but ARIN deferred to the IETF before -implementing the policy indicating that the matter was not a typical -allocation issue but a reservation of addresses for technical purposes -(per :rfc:`2860`). - -IETF published :rfc:`6598`, detailing a shared address space for use in -ISP CGN deployments that can handle the same network prefixes occurring -both on inbound and outbound interfaces. ARIN returned address space to -the :abbr:`IANA (Internet Assigned Numbers Authority)` for this -allocation. - -The allocated address block is 100.64.0.0/10. - -Devices evaluating whether an IPv4 address is public must be updated to -recognize the new address space. Allocating more private IPv4 address -space for NAT devices might prolong the transition to IPv6. - -Overview -======== - -Different NAT Types -------------------- - -.. _source-nat: - -SNAT -^^^^ - -:abbr:`SNAT (Source Network Address Translation)` is the most common -form of :abbr:`NAT (Network Address Translation)` and is typically -referred to simply as NAT. To be more correct, what most people refer -to as :abbr:`NAT (Network Address Translation)` is actually the process -of :abbr:`PAT (Port Address Translation)`, or NAT overload. SNAT is -typically used by internal users/private hosts to access the Internet -- the source address is translated and thus kept private. - -.. _destination-nat: - -DNAT -^^^^ - -:abbr:`DNAT (Destination Network Address Translation)` changes the -destination address of packets passing through the router, while -:ref:`source-nat` changes the source address of packets. DNAT is -typically used when an external (public) host needs to initiate a -session with an internal (private) host. A customer needs to access a -private service behind the routers public IP. A connection is -established with the routers public IP address on a well known port and -thus all traffic for this port is rewritten to address the internal -(private) host. - -.. _bidirectional-nat: - -Bidirectional NAT -^^^^^^^^^^^^^^^^^ - -This is a common scenario where both :ref:`source-nat` and -:ref:`destination-nat` are configured at the same time. It's commonly -used then internal (private) hosts need to establish a connection with -external resources and external systems need to access internal -(private) resources. - -NAT, Routing, Firewall Interaction ----------------------------------- - -There is a very nice picture/explanation in the Vyatta documentation -which should be rewritten here. - -NAT Ruleset ------------ - -:abbr:`NAT (Network Address Translation)` is configured entirely on a -series of so called `rules`. Rules are numbered and evaluated by the -underlying OS in numerical order! The rule numbers can be changes by -utilizing the :cfgcmd:`rename` and :cfgcmd:`copy` commands. - -.. note:: Changes to the NAT system only affect newly established - connections. Already established connections are not affected. - -.. hint:: When designing your NAT ruleset leave some space between - consecutive rules for later extension. Your ruleset could start with - numbers 10, 20, 30. You thus can later extend the ruleset and place - new rules between existing ones. - -Rules will be created for both :ref:`source-nat` and -:ref:`destination-nat`. - -For :ref:`bidirectional-nat` a rule for both :ref:`source-nat` and -:ref:`destination-nat` needs to be created. - -.. _traffic-filters: - -Traffic Filters ---------------- - -Traffic Filters are used to control which packets will have the defined -NAT rules applied. Five different filters can be applied within a NAT -rule. - -* **outbound-interface** - applicable only to :ref:`source-nat`. It - configures the interface which is used for the outside traffic that - this translation rule applies to. - - Example: - - .. code-block:: none - - set nat source rule 20 outbound-interface eth0 - -* **inbound-interface** - applicable only to :ref:`destination-nat`. It - configures the interface which is used for the inside traffic the - translation rule applies to. - - Example: - - .. code-block:: none - - set nat destination rule 20 inbound-interface eth1 - -* **protocol** - specify which types of protocols this translation rule - applies to. Only packets matching the specified protocol are NATed. - By default this applies to `all` protocols. - - Example: - - * Set SNAT rule 20 to only NAT TCP and UDP packets - * Set DNAT rule 20 to only NAT UDP packets - - .. code-block:: none - - set nat source rule 20 protocol tcp_udp - set nat destination rule 20 protocol udp - -* **source** - specifies which packets the NAT translation rule applies - to based on the packets source IP address and/or source port. Only - matching packets are considered for NAT. - - Example: - - * Set SNAT rule 20 to only NAT packets arriving from the 192.0.2.0/24 - network - * Set SNAT rule 30 to only NAT packets arriving from the 203.0.113.0/24 - network with a source port of 80 and 443 - - .. code-block:: none - - set nat source rule 20 source address 192.0.2.0/24 - set nat source rule 30 source address 203.0.113.0/24 - set nat source rule 30 source port 80,443 - - -* **destination** - specify which packets the translation will be - applied to, only based on the destination address and/or port number - configured. - - .. note:: If no destination is specified the rule will match on any - destination address and port. - - Example: - - * Configure SNAT rule (40) to only NAT packets with a destination - address of 192.0.2.1. - - .. code-block:: none - - set nat source rule 40 destination address 192.0.2.1 - - -Address Conversion ------------------- - -Every NAT rule has a translation command defined. The address defined -for the translation is the address used when the address information in -a packet is replaced. - -Source Address -^^^^^^^^^^^^^^ - -For :ref:`source-nat` rules the packets source address will be replaced -with the address specified in the translation command. A port -translation can also be specified and is part of the translation -address. - -.. note:: The translation address must be set to one of the available - addresses on the configured `outbound-interface` or it must be set to - `masquerade` which will use the primary IP address of the - `outbound-interface` as its translation address. - -.. note:: When using NAT for a large number of host systems it - recommended that a minimum of 1 IP address is used to NAT every 256 - private host systems. This is due to the limit of 65,000 port numbers - available for unique translations and a reserving an average of - 200-300 sessions per host system. - -Example: - -* Define a discrete source IP address of 100.64.0.1 for SNAT rule 20 -* Use address `masquerade` (the interfaces primary address) on rule 30 -* For a large amount of private machines behind the NAT your address - pool might to be bigger. Use any address in the range 100.64.0.10 - - 100.64.0.20 on SNAT rule 40 when doing the translation - - -.. code-block:: none - - set nat source rule 20 translation address 100.64.0.1 - set nat source rule 30 translation address 'masquerade' - set nat source rule 40 translation address 100.64.0.10-100.64.0.20 - - -Destination Address -^^^^^^^^^^^^^^^^^^^ - -For :ref:`destination-nat` rules the packets destination address will be -replaced by the specified address in the `translation address` command. - -Example: - -* DNAT rule 10 replaces the destination address of an inbound packet - with 192.0.2.10 - -.. code-block:: none - - set nat destination rule 10 translation address 192.0.2.10 - - -Configuration Examples -====================== - -To setup SNAT, we need to know: - -* The internal IP addresses we want to translate -* The outgoing interface to perform the translation on -* The external IP address to translate to - -In the example used for the Quick Start configuration above, we -demonstrate the following configuration: - -.. code-block:: none - - set nat source rule 100 outbound-interface 'eth0' - set nat source rule 100 source address '192.168.0.0/24' - set nat source rule 100 translation address 'masquerade' - -Which generates the following configuration: - -.. code-block:: none - - rule 100 { - outbound-interface eth0 - source { - address 192.168.0.0/24 - } - translation { - address masquerade - } - } - -In this example, we use **masquerade** as the translation address -instead of an IP address. The **masquerade** target is effectively an -alias to say "use whatever IP address is on the outgoing interface", -rather than a statically configured IP address. This is useful if you -use DHCP for your outgoing interface and do not know what the external -address will be. - -When using NAT for a large number of host systems it recommended that a -minimum of 1 IP address is used to NAT every 256 host systems. This is -due to the limit of 65,000 port numbers available for unique -translations and a reserving an average of 200-300 sessions per host -system. - -Example: For an ~8,000 host network a source NAT pool of 32 IP addresses -is recommended. - -A pool of addresses can be defined by using a hyphen between two IP -addresses: - -.. code-block:: none - - set nat source rule 100 translation address '203.0.113.32-203.0.113.63' - -.. _avoidng_leaky_nat: - -Avoiding "leaky" NAT --------------------- - -Linux netfilter will not NAT traffic marked as INVALID. This often -confuses people into thinking that Linux (or specifically VyOS) has a -broken NAT implementation because non-NATed traffic is seen leaving an -external interface. This is actually working as intended, and a packet -capture of the "leaky" traffic should reveal that the traffic is either -an additional TCP "RST", "FIN,ACK", or "RST,ACK" sent by client systems -after Linux netfilter considers the connection closed. The most common -is the additional TCP RST some host implementations send after -terminating a connection (which is implementation-specific). - -In other words, connection tracking has already observed the connection -be closed and has transition the flow to INVALID to prevent attacks from -attempting to reuse the connection. - -You can avoid the "leaky" behavior by using a firewall policy that drops -"invalid" state packets. - -Having control over the matching of INVALID state traffic, e.g. the -ability to selectively log, is an important troubleshooting tool for -observing broken protocol behavior. For this reason, VyOS does not -globally drop invalid state traffic, instead allowing the operator to -make the determination on how the traffic is handled. - -.. _hairpin_nat_reflection: - -Hairpin NAT/NAT Reflection --------------------------- - -A typical problem with using NAT and hosting public servers is the -ability for internal systems to reach an internal server using it's -external IP address. The solution to this is usually the use of -split-DNS to correctly point host systems to the internal address when -requests are made internally. Because many smaller networks lack DNS -infrastructure, a work-around is commonly deployed to facilitate the -traffic by NATing the request from internal hosts to the source address -of the internal interface on the firewall. - -This technique is commonly referred to as NAT Reflection or Hairpin NAT. - -Example: - -* Redirect Microsoft RDP traffic from the outside (WAN, external) world - via :ref:`destination-nat` in rule 100 to the internal, private host - 192.0.2.40. - -* Redirect Microsoft RDP traffic from the internal (LAN, private) - network via :ref:`destination-nat` in rule 110 to the internal, - private host 192.0.2.40. We also need a :ref:`source-nat` rule 110 for - the reverse path of the traffic. The internal network 192.0.2.0/24 is - reachable via interface `eth0.10`. - -.. code-block:: none - - set nat destination rule 100 description 'Regular destination NAT from external' - set nat destination rule 100 destination port '3389' - set nat destination rule 100 inbound-interface 'pppoe0' - set nat destination rule 100 protocol 'tcp' - set nat destination rule 100 translation address '192.0.2.40' - - set nat destination rule 110 description 'NAT Reflection: INSIDE' - set nat destination rule 110 destination port '3389' - set nat destination rule 110 inbound-interface 'eth0.10' - set nat destination rule 110 protocol 'tcp' - set nat destination rule 110 translation address '192.0.2.40' - - set nat source rule 110 description 'NAT Reflection: INSIDE' - set nat source rule 110 destination address '192.0.2.0/24' - set nat source rule 110 outbound-interface 'eth0.10' - set nat source rule 110 protocol 'tcp' - set nat source rule 110 source address '192.0.2.0/24' - set nat source rule 110 translation address 'masquerade' - -Which results in a configuration of: - -.. code-block:: none - - vyos@vyos# show nat - destination { - rule 100 { - description "Regular destination NAT from external" - destination { - port 3389 - } - inbound-interface pppoe0 - protocol tcp - translation { - address 192.0.2.40 - } - } - rule 110 { - description "NAT Reflection: INSIDE" - destination { - port 3389 - } - inbound-interface eth0.10 - protocol tcp - translation { - address 192.0.2.40 - } - } - } - source { - rule 110 { - description "NAT Reflection: INSIDE" - destination { - address 192.0.2.0/24 - } - outbound-interface eth0.10 - protocol tcp - source { - address 192.0.2.0/24 - } - translation { - address masquerade - } - } - } - - -Destination NAT ---------------- - -DNAT is typically referred to as a **Port Forward**. When using VyOS as -a NAT router and firewall, a common configuration task is to redirect -incoming traffic to a system behind the firewall. - -In this example, we will be using the example Quick Start configuration -above as a starting point. - -To setup a destination NAT rule we need to gather: - -* The interface traffic will be coming in on; -* The protocol and port we wish to forward; -* The IP address of the internal system we wish to forward traffic to. - -In our example, we will be forwarding web server traffic to an internal -web server on 192.168.0.100. HTTP traffic makes use of the TCP protocol -on port 80. For other common port numbers, see: -https://en.wikipedia.org/wiki/List_of_TCP_and_UDP_port_numbers - -Our configuration commands would be: - -.. code-block:: none - - set nat destination rule 10 description 'Port Forward: HTTP to 192.168.0.100' - set nat destination rule 10 destination port '80' - set nat destination rule 10 inbound-interface 'eth0' - set nat destination rule 10 protocol 'tcp' - set nat destination rule 10 translation address '192.168.0.100' - -Which would generate the following NAT destination configuration: - -.. code-block:: none - - nat { - destination { - rule 10 { - description "Port Forward: HTTP to 192.168.0.100" - destination { - port 80 - } - inbound-interface eth0 - protocol tcp - translation { - address 192.168.0.100 - } - } - } - } - -.. note:: If forwarding traffic to a different port than it is arriving - on, you may also configure the translation port using - `set nat destination rule [n] translation port`. - -This establishes our Port Forward rule, but if we created a firewall -policy it will likely block the traffic. - -It is important to note that when creating firewall rules that the DNAT -translation occurs **before** traffic traverses the firewall. In other -words, the destination address has already been translated to -192.168.0.100. - -So in our firewall policy, we want to allow traffic coming in on the -outside interface, destined for TCP port 80 and the IP address of -192.168.0.100. - -.. code-block:: none - - set firewall name OUTSIDE-IN rule 20 action 'accept' - set firewall name OUTSIDE-IN rule 20 destination address '192.168.0.100' - set firewall name OUTSIDE-IN rule 20 destination port '80' - set firewall name OUTSIDE-IN rule 20 protocol 'tcp' - set firewall name OUTSIDE-IN rule 20 state new 'enable' - -This would generate the following configuration: - -.. code-block:: none - - rule 20 { - action accept - destination { - address 192.168.0.100 - port 80 - } - protocol tcp - state { - new enable - } - } - -.. note:: - - If you have configured the `INSIDE-OUT` policy, you will need to add - additional rules to permit inbound NAT traffic. - -1-to-1 NAT ----------- - -Another term often used for DNAT is **1-to-1 NAT**. For a 1-to-1 NAT -configuration, both DNAT and SNAT are used to NAT all traffic from an -external IP address to an internal IP address and vice-versa. - -Typically, a 1-to-1 NAT rule omits the destination port (all ports) and -replaces the protocol with either **all** or **ip**. - -Then a corresponding SNAT rule is created to NAT outgoing traffic for -the internal IP to a reserved external IP. This dedicates an external IP -address to an internal IP address and is useful for protocols which -don't have the notion of ports, such as GRE. - -Here's an extract of a simple 1-to-1 NAT configuration with one internal -and one external interface: - -.. code-block:: none - - set interfaces ethernet eth0 address '192.168.1.1/24' - set interfaces ethernet eth0 description 'Inside interface' - set interfaces ethernet eth1 address '192.0.2.30/24' - set interfaces ethernet eth1 description 'Outside interface' - set nat destination rule 2000 description '1-to-1 NAT example' - set nat destination rule 2000 destination address '192.0.2.30' - set nat destination rule 2000 inbound-interface 'eth1' - set nat destination rule 2000 translation address '192.168.1.10' - set nat source rule 2000 description '1-to-1 NAT example' - set nat source rule 2000 outbound-interface 'eth1' - set nat source rule 2000 source address '192.168.1.10' - set nat source rule 2000 translation address '192.0.2.30' - -Firewall rules are written as normal, using the internal IP address as -the source of outbound rules and the destination of inbound rules. - -NAT before VPN --------------- - -Some application service providers (ASPs) operate a VPN gateway to -provide access to their internal resources, and require that a -connecting organisation translate all traffic to the service provider -network to a source address provided by the ASP. - -Example Network -^^^^^^^^^^^^^^^ - -Here's one example of a network environment for an ASP. -The ASP requests that all connections from this company should come from -172.29.41.89 - an address that is assigned by the ASP and not in use at -the customer site. - -.. figure:: /_static/images/nat_before_vpn_topology.png - :scale: 100 % - :alt: NAT before VPN Topology - - NAT before VPN Topology - - -Configuration -^^^^^^^^^^^^^ - -The required configuration can be broken down into 4 major pieces: - -* A dummy interface for the provider-assigned IP; -* NAT (specifically, Source NAT); -* IPSec IKE and ESP Groups; -* IPSec VPN tunnels. - - -Dummy interface -""""""""""""""" - -The dummy interface allows us to have an equivalent of the Cisco IOS -Loopback interface - a router-internal interface we can use for IP -addresses the router must know about, but which are not actually -assigned to a real network. - -We only need a single step for this interface: - -.. code-block:: none - - set interfaces dummy dum0 address '172.29.41.89/32' - -NAT Configuration -""""""""""""""""" - -.. code-block:: none - - set nat source rule 110 description 'Internal to ASP' - set nat source rule 110 destination address '172.27.1.0/24' - set nat source rule 110 outbound-interface 'any' - set nat source rule 110 source address '192.168.43.0/24' - set nat source rule 110 translation address '172.29.41.89' - set nat source rule 120 description 'Internal to ASP' - set nat source rule 120 destination address '10.125.0.0/16' - set nat source rule 120 outbound-interface 'any' - set nat source rule 120 source address '192.168.43.0/24' - set nat source rule 120 translation address '172.29.41.89' - -IPSec IKE and ESP -""""""""""""""""" - -The ASP has documented their IPSec requirements: - -* IKE Phase: - - * aes256 Encryption - * sha256 Hashes - -* ESP Phase: - - * aes256 Encryption - * sha256 Hashes - * DH Group 14 - - -Additionally, we want to use VPNs only on our eth1 interface (the -external interface in the image above) - -.. code-block:: none - - set vpn ipsec ike-group my-ike ikev2-reauth 'no' - set vpn ipsec ike-group my-ike key-exchange 'ikev1' - set vpn ipsec ike-group my-ike lifetime '7800' - set vpn ipsec ike-group my-ike proposal 1 dh-group '14' - set vpn ipsec ike-group my-ike proposal 1 encryption 'aes256' - set vpn ipsec ike-group my-ike proposal 1 hash 'sha256' - - set vpn ipsec esp-group my-esp compression 'disable' - set vpn ipsec esp-group my-esp lifetime '3600' - set vpn ipsec esp-group my-esp mode 'tunnel' - set vpn ipsec esp-group my-esp pfs 'disable' - set vpn ipsec esp-group my-esp proposal 1 encryption 'aes256' - set vpn ipsec esp-group my-esp proposal 1 hash 'sha256' - - set vpn ipsec ipsec-interfaces interface 'eth1' - -IPSec VPN Tunnels -""""""""""""""""" - -We'll use the IKE and ESP groups created above for this VPN. Because we -need access to 2 different subnets on the far side, we will need two -different tunnels. If you changed the names of the ESP group and IKE -group in the previous step, make sure you use the correct names here -too. - -.. code-block:: none - - set vpn ipsec site-to-site peer 198.51.100.243 authentication mode 'pre-shared-secret' - set vpn ipsec site-to-site peer 198.51.100.243 authentication pre-shared-secret 'PASSWORD IS HERE' - set vpn ipsec site-to-site peer 198.51.100.243 connection-type 'initiate' - set vpn ipsec site-to-site peer 198.51.100.243 default-esp-group 'my-esp' - set vpn ipsec site-to-site peer 198.51.100.243 ike-group 'my-ike' - set vpn ipsec site-to-site peer 198.51.100.243 ikev2-reauth 'inherit' - set vpn ipsec site-to-site peer 198.51.100.243 local-address '203.0.113.46' - set vpn ipsec site-to-site peer 198.51.100.243 tunnel 0 local prefix '172.29.41.89/32' - set vpn ipsec site-to-site peer 198.51.100.243 tunnel 0 remote prefix '172.27.1.0/24' - set vpn ipsec site-to-site peer 198.51.100.243 tunnel 1 local prefix '172.29.41.89/32' - set vpn ipsec site-to-site peer 198.51.100.243 tunnel 1 remote prefix '10.125.0.0/16' - -Testing and Validation -"""""""""""""""""""""" - -If you've completed all the above steps you no doubt want to see if it's -all working. - -Start by checking for IPSec SAs (Security Associations) with: - -.. code-block:: none - - $ show vpn ipsec sa - - Peer ID / IP Local ID / IP - ------------ ------------- - 198.51.100.243 203.0.113.46 - - Tunnel State Bytes Out/In Encrypt Hash NAT-T A-Time L-Time Proto - ------ ----- ------------- ------- ---- ----- ------ ------ ----- - 0 up 0.0/0.0 aes256 sha256 no 1647 3600 all - 1 up 0.0/0.0 aes256 sha256 no 865 3600 all - -That looks good - we defined 2 tunnels and they're both up and running. + nat44 + nat66 diff --git a/docs/configuration/nat/nat44.rst b/docs/configuration/nat/nat44.rst new file mode 100644 index 00000000..59cee741 --- /dev/null +++ b/docs/configuration/nat/nat44.rst @@ -0,0 +1,733 @@ +.. _nat44: + +##### +NAT44 +##### + +:abbr:`NAT (Network Address Translation)` is a common method of +remapping one IP address space into another by modifying network address +information in the IP header of packets while they are in transit across +a traffic routing device. The technique was originally used as a +shortcut to avoid the need to readdress every host when a network was +moved. It has become a popular and essential tool in conserving global +address space in the face of IPv4 address exhaustion. One +Internet-routable IP address of a NAT gateway can be used for an entire +private network. + +IP masquerading is a technique that hides an entire IP address space, +usually consisting of private IP addresses, behind a single IP address +in another, usually public address space. The hidden addresses are +changed into a single (public) IP address as the source address of the +outgoing IP packets so they appear as originating not from the hidden +host but from the routing device itself. Because of the popularity of +this technique to conserve IPv4 address space, the term NAT has become +virtually synonymous with IP masquerading. + +As network address translation modifies the IP address information in +packets, NAT implementations may vary in their specific behavior in +various addressing cases and their effect on network traffic. The +specifics of NAT behavior are not commonly documented by vendors of +equipment containing NAT implementations. + +The computers on an internal network can use any of the addresses set +aside by the :abbr:`IANA (Internet Assigned Numbers Authority)` for +private addressing (see :rfc:`1918`). These reserved IP addresses are +not in use on the Internet, so an external machine will not directly +route to them. The following addresses are reserved for private use: + +* 10.0.0.0 to 10.255.255.255 (CIDR: 10.0.0.0/8) +* 172.16.0.0 to 172.31.255.255 (CIDR: 172.16.0.0/12) +* 192.168.0.0 to 192.168.255.255 (CIDR: 192.168.0.0/16) + + +If an ISP deploys a :abbr:`CGN (Carrier-grade NAT)`, and uses +:rfc:`1918` address space to number customer gateways, the risk of +address collision, and therefore routing failures, arises when the +customer network already uses an :rfc:`1918` address space. + +This prompted some ISPs to develop a policy within the :abbr:`ARIN +(American Registry for Internet Numbers)` to allocate new private +address space for CGNs, but ARIN deferred to the IETF before +implementing the policy indicating that the matter was not a typical +allocation issue but a reservation of addresses for technical purposes +(per :rfc:`2860`). + +IETF published :rfc:`6598`, detailing a shared address space for use in +ISP CGN deployments that can handle the same network prefixes occurring +both on inbound and outbound interfaces. ARIN returned address space to +the :abbr:`IANA (Internet Assigned Numbers Authority)` for this +allocation. + +The allocated address block is 100.64.0.0/10. + +Devices evaluating whether an IPv4 address is public must be updated to +recognize the new address space. Allocating more private IPv4 address +space for NAT devices might prolong the transition to IPv6. + +Overview +======== + +Different NAT Types +------------------- + +.. _source-nat: + +SNAT +^^^^ + +:abbr:`SNAT (Source Network Address Translation)` is the most common +form of :abbr:`NAT (Network Address Translation)` and is typically +referred to simply as NAT. To be more correct, what most people refer +to as :abbr:`NAT (Network Address Translation)` is actually the process +of :abbr:`PAT (Port Address Translation)`, or NAT overload. SNAT is +typically used by internal users/private hosts to access the Internet +- the source address is translated and thus kept private. + +.. _destination-nat: + +DNAT +^^^^ + +:abbr:`DNAT (Destination Network Address Translation)` changes the +destination address of packets passing through the router, while +:ref:`source-nat` changes the source address of packets. DNAT is +typically used when an external (public) host needs to initiate a +session with an internal (private) host. A customer needs to access a +private service behind the routers public IP. A connection is +established with the routers public IP address on a well known port and +thus all traffic for this port is rewritten to address the internal +(private) host. + +.. _bidirectional-nat: + +Bidirectional NAT +^^^^^^^^^^^^^^^^^ + +This is a common scenario where both :ref:`source-nat` and +:ref:`destination-nat` are configured at the same time. It's commonly +used then internal (private) hosts need to establish a connection with +external resources and external systems need to access internal +(private) resources. + +NAT, Routing, Firewall Interaction +---------------------------------- + +There is a very nice picture/explanation in the Vyatta documentation +which should be rewritten here. + +NAT Ruleset +----------- + +:abbr:`NAT (Network Address Translation)` is configured entirely on a +series of so called `rules`. Rules are numbered and evaluated by the +underlying OS in numerical order! The rule numbers can be changes by +utilizing the :cfgcmd:`rename` and :cfgcmd:`copy` commands. + +.. note:: Changes to the NAT system only affect newly established + connections. Already established connections are not affected. + +.. hint:: When designing your NAT ruleset leave some space between + consecutive rules for later extension. Your ruleset could start with + numbers 10, 20, 30. You thus can later extend the ruleset and place + new rules between existing ones. + +Rules will be created for both :ref:`source-nat` and +:ref:`destination-nat`. + +For :ref:`bidirectional-nat` a rule for both :ref:`source-nat` and +:ref:`destination-nat` needs to be created. + +.. _traffic-filters: + +Traffic Filters +--------------- + +Traffic Filters are used to control which packets will have the defined +NAT rules applied. Five different filters can be applied within a NAT +rule. + +* **outbound-interface** - applicable only to :ref:`source-nat`. It + configures the interface which is used for the outside traffic that + this translation rule applies to. + + Example: + + .. code-block:: none + + set nat source rule 20 outbound-interface eth0 + +* **inbound-interface** - applicable only to :ref:`destination-nat`. It + configures the interface which is used for the inside traffic the + translation rule applies to. + + Example: + + .. code-block:: none + + set nat destination rule 20 inbound-interface eth1 + +* **protocol** - specify which types of protocols this translation rule + applies to. Only packets matching the specified protocol are NATed. + By default this applies to `all` protocols. + + Example: + + * Set SNAT rule 20 to only NAT TCP and UDP packets + * Set DNAT rule 20 to only NAT UDP packets + + .. code-block:: none + + set nat source rule 20 protocol tcp_udp + set nat destination rule 20 protocol udp + +* **source** - specifies which packets the NAT translation rule applies + to based on the packets source IP address and/or source port. Only + matching packets are considered for NAT. + + Example: + + * Set SNAT rule 20 to only NAT packets arriving from the 192.0.2.0/24 + network + * Set SNAT rule 30 to only NAT packets arriving from the 203.0.113.0/24 + network with a source port of 80 and 443 + + .. code-block:: none + + set nat source rule 20 source address 192.0.2.0/24 + set nat source rule 30 source address 203.0.113.0/24 + set nat source rule 30 source port 80,443 + + +* **destination** - specify which packets the translation will be + applied to, only based on the destination address and/or port number + configured. + + .. note:: If no destination is specified the rule will match on any + destination address and port. + + Example: + + * Configure SNAT rule (40) to only NAT packets with a destination + address of 192.0.2.1. + + .. code-block:: none + + set nat source rule 40 destination address 192.0.2.1 + + +Address Conversion +------------------ + +Every NAT rule has a translation command defined. The address defined +for the translation is the address used when the address information in +a packet is replaced. + +Source Address +^^^^^^^^^^^^^^ + +For :ref:`source-nat` rules the packets source address will be replaced +with the address specified in the translation command. A port +translation can also be specified and is part of the translation +address. + +.. note:: The translation address must be set to one of the available + addresses on the configured `outbound-interface` or it must be set to + `masquerade` which will use the primary IP address of the + `outbound-interface` as its translation address. + +.. note:: When using NAT for a large number of host systems it + recommended that a minimum of 1 IP address is used to NAT every 256 + private host systems. This is due to the limit of 65,000 port numbers + available for unique translations and a reserving an average of + 200-300 sessions per host system. + +Example: + +* Define a discrete source IP address of 100.64.0.1 for SNAT rule 20 +* Use address `masquerade` (the interfaces primary address) on rule 30 +* For a large amount of private machines behind the NAT your address + pool might to be bigger. Use any address in the range 100.64.0.10 - + 100.64.0.20 on SNAT rule 40 when doing the translation + + +.. code-block:: none + + set nat source rule 20 translation address 100.64.0.1 + set nat source rule 30 translation address 'masquerade' + set nat source rule 40 translation address 100.64.0.10-100.64.0.20 + + +Destination Address +^^^^^^^^^^^^^^^^^^^ + +For :ref:`destination-nat` rules the packets destination address will be +replaced by the specified address in the `translation address` command. + +Example: + +* DNAT rule 10 replaces the destination address of an inbound packet + with 192.0.2.10 + +.. code-block:: none + + set nat destination rule 10 translation address 192.0.2.10 + + +Configuration Examples +====================== + +To setup SNAT, we need to know: + +* The internal IP addresses we want to translate +* The outgoing interface to perform the translation on +* The external IP address to translate to + +In the example used for the Quick Start configuration above, we +demonstrate the following configuration: + +.. code-block:: none + + set nat source rule 100 outbound-interface 'eth0' + set nat source rule 100 source address '192.168.0.0/24' + set nat source rule 100 translation address 'masquerade' + +Which generates the following configuration: + +.. code-block:: none + + rule 100 { + outbound-interface eth0 + source { + address 192.168.0.0/24 + } + translation { + address masquerade + } + } + +In this example, we use **masquerade** as the translation address +instead of an IP address. The **masquerade** target is effectively an +alias to say "use whatever IP address is on the outgoing interface", +rather than a statically configured IP address. This is useful if you +use DHCP for your outgoing interface and do not know what the external +address will be. + +When using NAT for a large number of host systems it recommended that a +minimum of 1 IP address is used to NAT every 256 host systems. This is +due to the limit of 65,000 port numbers available for unique +translations and a reserving an average of 200-300 sessions per host +system. + +Example: For an ~8,000 host network a source NAT pool of 32 IP addresses +is recommended. + +A pool of addresses can be defined by using a hyphen between two IP +addresses: + +.. code-block:: none + + set nat source rule 100 translation address '203.0.113.32-203.0.113.63' + +.. _avoidng_leaky_nat: + +Avoiding "leaky" NAT +-------------------- + +Linux netfilter will not NAT traffic marked as INVALID. This often +confuses people into thinking that Linux (or specifically VyOS) has a +broken NAT implementation because non-NATed traffic is seen leaving an +external interface. This is actually working as intended, and a packet +capture of the "leaky" traffic should reveal that the traffic is either +an additional TCP "RST", "FIN,ACK", or "RST,ACK" sent by client systems +after Linux netfilter considers the connection closed. The most common +is the additional TCP RST some host implementations send after +terminating a connection (which is implementation-specific). + +In other words, connection tracking has already observed the connection +be closed and has transition the flow to INVALID to prevent attacks from +attempting to reuse the connection. + +You can avoid the "leaky" behavior by using a firewall policy that drops +"invalid" state packets. + +Having control over the matching of INVALID state traffic, e.g. the +ability to selectively log, is an important troubleshooting tool for +observing broken protocol behavior. For this reason, VyOS does not +globally drop invalid state traffic, instead allowing the operator to +make the determination on how the traffic is handled. + +.. _hairpin_nat_reflection: + +Hairpin NAT/NAT Reflection +-------------------------- + +A typical problem with using NAT and hosting public servers is the +ability for internal systems to reach an internal server using it's +external IP address. The solution to this is usually the use of +split-DNS to correctly point host systems to the internal address when +requests are made internally. Because many smaller networks lack DNS +infrastructure, a work-around is commonly deployed to facilitate the +traffic by NATing the request from internal hosts to the source address +of the internal interface on the firewall. + +This technique is commonly referred to as NAT Reflection or Hairpin NAT. + +Example: + +* Redirect Microsoft RDP traffic from the outside (WAN, external) world + via :ref:`destination-nat` in rule 100 to the internal, private host + 192.0.2.40. + +* Redirect Microsoft RDP traffic from the internal (LAN, private) + network via :ref:`destination-nat` in rule 110 to the internal, + private host 192.0.2.40. We also need a :ref:`source-nat` rule 110 for + the reverse path of the traffic. The internal network 192.0.2.0/24 is + reachable via interface `eth0.10`. + +.. code-block:: none + + set nat destination rule 100 description 'Regular destination NAT from external' + set nat destination rule 100 destination port '3389' + set nat destination rule 100 inbound-interface 'pppoe0' + set nat destination rule 100 protocol 'tcp' + set nat destination rule 100 translation address '192.0.2.40' + + set nat destination rule 110 description 'NAT Reflection: INSIDE' + set nat destination rule 110 destination port '3389' + set nat destination rule 110 inbound-interface 'eth0.10' + set nat destination rule 110 protocol 'tcp' + set nat destination rule 110 translation address '192.0.2.40' + + set nat source rule 110 description 'NAT Reflection: INSIDE' + set nat source rule 110 destination address '192.0.2.0/24' + set nat source rule 110 outbound-interface 'eth0.10' + set nat source rule 110 protocol 'tcp' + set nat source rule 110 source address '192.0.2.0/24' + set nat source rule 110 translation address 'masquerade' + +Which results in a configuration of: + +.. code-block:: none + + vyos@vyos# show nat + destination { + rule 100 { + description "Regular destination NAT from external" + destination { + port 3389 + } + inbound-interface pppoe0 + protocol tcp + translation { + address 192.0.2.40 + } + } + rule 110 { + description "NAT Reflection: INSIDE" + destination { + port 3389 + } + inbound-interface eth0.10 + protocol tcp + translation { + address 192.0.2.40 + } + } + } + source { + rule 110 { + description "NAT Reflection: INSIDE" + destination { + address 192.0.2.0/24 + } + outbound-interface eth0.10 + protocol tcp + source { + address 192.0.2.0/24 + } + translation { + address masquerade + } + } + } + + +Destination NAT +--------------- + +DNAT is typically referred to as a **Port Forward**. When using VyOS as +a NAT router and firewall, a common configuration task is to redirect +incoming traffic to a system behind the firewall. + +In this example, we will be using the example Quick Start configuration +above as a starting point. + +To setup a destination NAT rule we need to gather: + +* The interface traffic will be coming in on; +* The protocol and port we wish to forward; +* The IP address of the internal system we wish to forward traffic to. + +In our example, we will be forwarding web server traffic to an internal +web server on 192.168.0.100. HTTP traffic makes use of the TCP protocol +on port 80. For other common port numbers, see: +https://en.wikipedia.org/wiki/List_of_TCP_and_UDP_port_numbers + +Our configuration commands would be: + +.. code-block:: none + + set nat destination rule 10 description 'Port Forward: HTTP to 192.168.0.100' + set nat destination rule 10 destination port '80' + set nat destination rule 10 inbound-interface 'eth0' + set nat destination rule 10 protocol 'tcp' + set nat destination rule 10 translation address '192.168.0.100' + +Which would generate the following NAT destination configuration: + +.. code-block:: none + + nat { + destination { + rule 10 { + description "Port Forward: HTTP to 192.168.0.100" + destination { + port 80 + } + inbound-interface eth0 + protocol tcp + translation { + address 192.168.0.100 + } + } + } + } + +.. note:: If forwarding traffic to a different port than it is arriving + on, you may also configure the translation port using + `set nat destination rule [n] translation port`. + +This establishes our Port Forward rule, but if we created a firewall +policy it will likely block the traffic. + +It is important to note that when creating firewall rules that the DNAT +translation occurs **before** traffic traverses the firewall. In other +words, the destination address has already been translated to +192.168.0.100. + +So in our firewall policy, we want to allow traffic coming in on the +outside interface, destined for TCP port 80 and the IP address of +192.168.0.100. + +.. code-block:: none + + set firewall name OUTSIDE-IN rule 20 action 'accept' + set firewall name OUTSIDE-IN rule 20 destination address '192.168.0.100' + set firewall name OUTSIDE-IN rule 20 destination port '80' + set firewall name OUTSIDE-IN rule 20 protocol 'tcp' + set firewall name OUTSIDE-IN rule 20 state new 'enable' + +This would generate the following configuration: + +.. code-block:: none + + rule 20 { + action accept + destination { + address 192.168.0.100 + port 80 + } + protocol tcp + state { + new enable + } + } + +.. note:: + + If you have configured the `INSIDE-OUT` policy, you will need to add + additional rules to permit inbound NAT traffic. + +1-to-1 NAT +---------- + +Another term often used for DNAT is **1-to-1 NAT**. For a 1-to-1 NAT +configuration, both DNAT and SNAT are used to NAT all traffic from an +external IP address to an internal IP address and vice-versa. + +Typically, a 1-to-1 NAT rule omits the destination port (all ports) and +replaces the protocol with either **all** or **ip**. + +Then a corresponding SNAT rule is created to NAT outgoing traffic for +the internal IP to a reserved external IP. This dedicates an external IP +address to an internal IP address and is useful for protocols which +don't have the notion of ports, such as GRE. + +Here's an extract of a simple 1-to-1 NAT configuration with one internal +and one external interface: + +.. code-block:: none + + set interfaces ethernet eth0 address '192.168.1.1/24' + set interfaces ethernet eth0 description 'Inside interface' + set interfaces ethernet eth1 address '192.0.2.30/24' + set interfaces ethernet eth1 description 'Outside interface' + set nat destination rule 2000 description '1-to-1 NAT example' + set nat destination rule 2000 destination address '192.0.2.30' + set nat destination rule 2000 inbound-interface 'eth1' + set nat destination rule 2000 translation address '192.168.1.10' + set nat source rule 2000 description '1-to-1 NAT example' + set nat source rule 2000 outbound-interface 'eth1' + set nat source rule 2000 source address '192.168.1.10' + set nat source rule 2000 translation address '192.0.2.30' + +Firewall rules are written as normal, using the internal IP address as +the source of outbound rules and the destination of inbound rules. + +NAT before VPN +-------------- + +Some application service providers (ASPs) operate a VPN gateway to +provide access to their internal resources, and require that a +connecting organisation translate all traffic to the service provider +network to a source address provided by the ASP. + +Example Network +^^^^^^^^^^^^^^^ + +Here's one example of a network environment for an ASP. +The ASP requests that all connections from this company should come from +172.29.41.89 - an address that is assigned by the ASP and not in use at +the customer site. + +.. figure:: /_static/images/nat_before_vpn_topology.png + :scale: 100 % + :alt: NAT before VPN Topology + + NAT before VPN Topology + + +Configuration +^^^^^^^^^^^^^ + +The required configuration can be broken down into 4 major pieces: + +* A dummy interface for the provider-assigned IP; +* NAT (specifically, Source NAT); +* IPSec IKE and ESP Groups; +* IPSec VPN tunnels. + + +Dummy interface +""""""""""""""" + +The dummy interface allows us to have an equivalent of the Cisco IOS +Loopback interface - a router-internal interface we can use for IP +addresses the router must know about, but which are not actually +assigned to a real network. + +We only need a single step for this interface: + +.. code-block:: none + + set interfaces dummy dum0 address '172.29.41.89/32' + +NAT Configuration +""""""""""""""""" + +.. code-block:: none + + set nat source rule 110 description 'Internal to ASP' + set nat source rule 110 destination address '172.27.1.0/24' + set nat source rule 110 outbound-interface 'any' + set nat source rule 110 source address '192.168.43.0/24' + set nat source rule 110 translation address '172.29.41.89' + set nat source rule 120 description 'Internal to ASP' + set nat source rule 120 destination address '10.125.0.0/16' + set nat source rule 120 outbound-interface 'any' + set nat source rule 120 source address '192.168.43.0/24' + set nat source rule 120 translation address '172.29.41.89' + +IPSec IKE and ESP +""""""""""""""""" + +The ASP has documented their IPSec requirements: + +* IKE Phase: + + * aes256 Encryption + * sha256 Hashes + +* ESP Phase: + + * aes256 Encryption + * sha256 Hashes + * DH Group 14 + + +Additionally, we want to use VPNs only on our eth1 interface (the +external interface in the image above) + +.. code-block:: none + + set vpn ipsec ike-group my-ike ikev2-reauth 'no' + set vpn ipsec ike-group my-ike key-exchange 'ikev1' + set vpn ipsec ike-group my-ike lifetime '7800' + set vpn ipsec ike-group my-ike proposal 1 dh-group '14' + set vpn ipsec ike-group my-ike proposal 1 encryption 'aes256' + set vpn ipsec ike-group my-ike proposal 1 hash 'sha256' + + set vpn ipsec esp-group my-esp compression 'disable' + set vpn ipsec esp-group my-esp lifetime '3600' + set vpn ipsec esp-group my-esp mode 'tunnel' + set vpn ipsec esp-group my-esp pfs 'disable' + set vpn ipsec esp-group my-esp proposal 1 encryption 'aes256' + set vpn ipsec esp-group my-esp proposal 1 hash 'sha256' + + set vpn ipsec ipsec-interfaces interface 'eth1' + +IPSec VPN Tunnels +""""""""""""""""" + +We'll use the IKE and ESP groups created above for this VPN. Because we +need access to 2 different subnets on the far side, we will need two +different tunnels. If you changed the names of the ESP group and IKE +group in the previous step, make sure you use the correct names here +too. + +.. code-block:: none + + set vpn ipsec site-to-site peer 198.51.100.243 authentication mode 'pre-shared-secret' + set vpn ipsec site-to-site peer 198.51.100.243 authentication pre-shared-secret 'PASSWORD IS HERE' + set vpn ipsec site-to-site peer 198.51.100.243 connection-type 'initiate' + set vpn ipsec site-to-site peer 198.51.100.243 default-esp-group 'my-esp' + set vpn ipsec site-to-site peer 198.51.100.243 ike-group 'my-ike' + set vpn ipsec site-to-site peer 198.51.100.243 ikev2-reauth 'inherit' + set vpn ipsec site-to-site peer 198.51.100.243 local-address '203.0.113.46' + set vpn ipsec site-to-site peer 198.51.100.243 tunnel 0 local prefix '172.29.41.89/32' + set vpn ipsec site-to-site peer 198.51.100.243 tunnel 0 remote prefix '172.27.1.0/24' + set vpn ipsec site-to-site peer 198.51.100.243 tunnel 1 local prefix '172.29.41.89/32' + set vpn ipsec site-to-site peer 198.51.100.243 tunnel 1 remote prefix '10.125.0.0/16' + +Testing and Validation +"""""""""""""""""""""" + +If you've completed all the above steps you no doubt want to see if it's +all working. + +Start by checking for IPSec SAs (Security Associations) with: + +.. code-block:: none + + $ show vpn ipsec sa + + Peer ID / IP Local ID / IP + ------------ ------------- + 198.51.100.243 203.0.113.46 + + Tunnel State Bytes Out/In Encrypt Hash NAT-T A-Time L-Time Proto + ------ ----- ------------- ------- ---- ----- ------ ------ ----- + 0 up 0.0/0.0 aes256 sha256 no 1647 3600 all + 1 up 0.0/0.0 aes256 sha256 no 865 3600 all + +That looks good - we defined 2 tunnels and they're both up and running. diff --git a/docs/configuration/nat/nat66.rst b/docs/configuration/nat/nat66.rst new file mode 100644 index 00000000..bcf5570f --- /dev/null +++ b/docs/configuration/nat/nat66.rst @@ -0,0 +1,127 @@ +.. _nat66: + +############ +NAT66(NPTv6) +############ + +:abbr:`NPTv6 (IPv6-to-IPv6 Network Prefix Translation)` is an address translation technology based +on IPv6 networks, used to convert an IPv6 address prefix in an IPv6 message into another IPv6 +address prefix. We call this address translation method NAT66. Devices that support the NAT66 +function are called NAT66 devices, which can provide NAT66 source and destination address +translation functions. + +Overview +======== + +Different NAT Types +------------------- + +.. _source-nat66: + +SNAT66 +^^^^^^ + +:abbr:`SNPTv6 (Source IPv6-to-IPv6 Network Prefix Translation)` The conversion function is mainly used in +the following scenarios: + +* A single internal network and external network. Use the NAT66 device to connect a single internal + network and public network, and the hosts in the internal network use IPv6 address prefixes that + only support routing within the local range. When a host in the internal network accesses the + external network, the source IPv6 address prefix in the message will be converted into a + global unicast IPv6 address prefix by the NAT66 device. +* Redundancy and load sharing. There are multiple NAT66 devices at the edge of an IPv6 network + to another IPv6 network. The path through the NAT66 device to another IPv6 network forms an + equivalent route, and traffic can be load-shared on these NAT66 devices. In this case, you + can configure the same source address translation rules on these NAT66 devices, so that any + NAT66 device can handle IPv6 traffic between different sites. +* Multi-homed. In a multi-homed network environment, the NAT66 device connects to an + internal network and simultaneously connects to different external networks. Address + translation can be configured on each external network side interface of the NAT66 + device to convert the same internal network address into different external network + addresses, and realize the mapping of the same internal address to multiple external addresses. + +.. _destination-nat66: + +DNAT66 +^^^^^^ + +The :abbr:`DNPTv6 (Destination IPv6-to-IPv6 Network Prefix Translation)` destination address translation +function is used in scenarios where the server in the internal network provides services to the external +network, such as providing Web services or FTP services to the external network. By configuring the mapping +relationship between the internal server address and the external network address on the external network +side interface of the NAT66 device, external network users can access the internal network server through +the designated external network address. + +Prefix Conversion +------------------ + +Source Prefix +^^^^^^^^^^^^^ + +Every SNAT66 rule has a translation command defined. The prefix defined +for the translation is the prefix used when the address information in +a packet is replaced.、 + +The :ref:`source-nat66` rule replaces the source address of the packet and calculates the +converted address using the prefix specified in the rule. + +Example: + +* Convert the address prefix of a single `fc01::/64` network to `fc00::/64` +* Output from `eth0` network interface + +.. code-block:: none + + set nat66 source rule 1 outbound-interface 'eth0' + set nat66 source rule 1 source prefix 'fc01::/64' + set nat66 source rule 1 translation prefix 'fc00::/64' + +Destination Prefix +^^^^^^^^^^^^^^^^^^ + +For the :ref:`destination-nat66` rule, the destination address of the packet is +replaced by the address calculated from the specified address or prefix in the +`translation address` command + +Example: + +* Convert the address prefix of a single `fc00::/64` network to `fc01::/64` +* Input from `eth0` network interface + +.. code-block:: none + + set nat66 destination rule 1 inbound-interface 'eth0' + set nat66 destination rule 1 destination address 'fc00::/64' + set nat66 destination rule 1 translation address 'fc01::/64' + +Configuration Examples +====================== + +Use the following topology to build a nat66 based isolated network between internal +and external networks (dynamic prefix is not supported): + +.. figure:: /_static/images/vyos_1_4_nat66_simple.png + :alt: VyOS NAT66 Simple Configure + +R1: + +.. code-block:: none + + set interfaces ethernet eth0 ipv6 address autoconf + set interfaces ethernet eth1 address 'fc01::1/64' + set nat66 destination rule 1 destination address 'fc00:470:f1cd:101::/64' + set nat66 destination rule 1 inbound-interface 'eth0' + set nat66 destination rule 1 translation address 'fc01::/64' + set nat66 source rule 1 outbound-interface 'eth0' + set nat66 source rule 1 source prefix 'fc01::/64' + set nat66 source rule 1 translation prefix 'fc00:470:f1cd:101::/64' + +R2: + +.. code-block:: none + + set interfaces bridge br1 address 'fc01::2/64' + set interfaces bridge br1 member interface eth0 + set interfaces bridge br1 member interface eth1 + set protocols static route6 ::/0 next-hop fc01::1 + set service router-advert interface br1 prefix ::/0 diff --git a/docs/configuration/nat/nptv6.rst b/docs/configuration/nat/nptv6.rst deleted file mode 100644 index c09c8336..00000000 --- a/docs/configuration/nat/nptv6.rst +++ /dev/null @@ -1,69 +0,0 @@ -.. include:: /_include/need_improvement.txt - -.. _nptv6: - -##### -NPTv6 -##### - -:abbr:`NPTv6 (Network Prefix Translation)` is a form of NAT for IPv6. It's -described in :rfc:`6296`. - -**Usage** - -NPTv6 is very useful for IPv6 multihoming. It is also commonly used when the -external IPv6 prefix is dynamic, as it prevents the need for renumbering of -internal hosts when the extern prefix changes. - -Let's assume the following network configuration: - -* eth0 : LAN -* eth1 : WAN1, with 2001:db8:e1::/48 routed towards it -* eth2 : WAN2, with 2001:db8:e2::/48 routed towards it - -Regarding LAN hosts addressing, why would you choose 2001:db8:e1::/48 over -2001:db8:e2::/48? What happens when you get a new provider with a different -routed IPv6 subnet? - -The solution here is to assign to your hosts ULAs_ and to prefix-translate -their address to the right subnet when going through your router. - -* LAN Subnet : fc00:dead:beef::/48 -* WAN 1 Subnet : 2001:db8:e1::/48 -* WAN 2 Subnet : 2001:db8:e2::/48 - -* eth0 addr : fc00:dead:beef::1/48 -* eth1 addr : 2001:db8:e1::1/48 -* eth2 addr : 2001:db8:e2::1/48 - -VyOS Support -^^^^^^^^^^^^ - -NPTv6 support has been added in VyOS 1.2 (Crux) and is available through -`nat nptv6` configuration nodes. - -.. code-block:: none - - set rule 10 source prefix 'fc00:dead:beef::/48' - set rule 10 outbound-interface 'eth1' - set rule 10 translation prefix '2001:db8:e1::/48' - set rule 20 source prefix 'fc00:dead:beef::/48' - set rule 20 outbound-interface 'eth2' - set rule 20 translation prefix '2001:db8:e2::/48' - -Resulting in the following ip6tables rules: - -.. code-block:: none - - Chain VYOS_DNPT_HOOK (1 references) - pkts bytes target prot opt in out source destination - 0 0 NETMAP all eth1 any anywhere 2001:db8:e1::/48 to:fc00:dead:beef::/48 - 0 0 NETMAP all eth2 any anywhere 2001:db8:e2::/48 to:fc00:dead:beef::/48 - 0 0 RETURN all any any anywhere anywhere - Chain VYOS_SNPT_HOOK (1 references) - pkts bytes target prot opt in out source destination - 0 0 NETMAP all any eth1 fc00:dead:beef::/48 anywhere to:2001:db8:e1::/48 - 0 0 NETMAP all any eth2 fc00:dead:beef::/48 anywhere to:2001:db8:e2::/48 - 0 0 RETURN all any any anywhere anywhere - -.. _ULAs: https://en.wikipedia.org/wiki/Unique_local_address diff --git a/docs/configuration/protocols/bgp.rst b/docs/configuration/protocols/bgp.rst index ddc7808d..6b6605a6 100644 --- a/docs/configuration/protocols/bgp.rst +++ b/docs/configuration/protocols/bgp.rst @@ -553,11 +553,11 @@ Common parametrs .. cfgcmd:: set protocols bgp <asn> parameters log-neighbor-changes - Tis command enable logging neighbor up/down changes and reset reason. + This command enable logging neighbor up/down changes and reset reason. .. cfgcmd:: set protocols bgp <asn> parameters no-client-to-client-reflection - Tis command disables route reflection between route reflector clients. + This command disables route reflection between route reflector clients. By default, the clients of a route reflector are not required to be fully meshed and the routes from a client are reflected to other clients. However, if the clients are fully meshed, route reflection is not required. @@ -566,8 +566,25 @@ Common parametrs .. cfgcmd:: set protocols bgp <asn> parameters no-fast-external-failover - Disable immediate sesison reset if peer's connected link goes down. + Disable immediate session reset if peer's connected link goes down. +.. cfgcmd:: set protocols bgp <asn> listen range <prefix> peer-group <name> + + This command is useful if one desires to loosen the requirement for BGP + to have strictly defined neighbors. Specifically what is allowed is for + the local router to listen to a range of IPv4 or IPv6 addresses defined + by a prefix and to accept BGP open messages. When a TCP connection + (and subsequently a BGP open message) from within this range tries to + connect the local router then the local router will respond and connect + with the parameters that are defined within the peer group. One must define + a peer-group for each range that is listed. If no peer-group is defined + then an error will keep you from committing the configuration. + +.. cfgcmd:: set protocols bgp <asn> listen limit <number> + + This command goes hand in hand with the listen range command to limit the + amount of BGP neighbors that are allowed to connect to the local router. + The limit range is 1 to 5000. Administrative Distance ^^^^^^^^^^^^^^^^^^^^^^^ diff --git a/docs/configuration/protocols/ospf.rst b/docs/configuration/protocols/ospf.rst index 2c098714..e1957cec 100644 --- a/docs/configuration/protocols/ospf.rst +++ b/docs/configuration/protocols/ospf.rst @@ -306,7 +306,7 @@ Area Configuration Interface Configuration ----------------------- -.. cfgcmd:: set interfaces <inttype> <intname> ip ospf authentication +.. cfgcmd:: set protocols ospf interface <interface> authentication plaintext-password <text> This command sets OSPF authentication key to a simple password. After @@ -315,7 +315,7 @@ Interface Configuration Simple text password authentication is insecure and deprecated in favour of MD5 HMAC authentication. -.. cfgcmd:: set interfaces <inttype> <intname> ip ospf authentication md5 +.. cfgcmd:: set protocols ospf interface <interface> authentication md5 key-id <id> md5-key <text> This command specifys that MD5 HMAC authentication must be used on this @@ -325,25 +325,34 @@ Interface Configuration The key can be long up to 16 chars (larger strings will be truncated), and is associated with the given key-id. -.. cfgcmd:: set interfaces <inttype> <intname> ip ospf bandwidth <number> +.. cfgcmd:: set protocols ospf interface <interface> bandwidth <number> This command sets the interface bandwidth for cost calculations, where bandwidth can be in range from 1 to 100000, specified in Mbits/s. -.. cfgcmd:: set interfaces <inttype> <intname> ip ospf cost <number> +.. cfgcmd:: set protocols ospf interface <interface> cost <number> This command sets link cost for the specified interface. The cost value is set to router-LSA’s metric field and used for SPF calculation. The cost range is 1 to 65535. -.. cfgcmd:: set interfaces <inttype> <intname> ip ospf dead-interval <number> +.. cfgcmd:: set protocols ospf interface <interface> dead-interval <number> Set number of seconds for router Dead Interval timer value used for Wait Timer and Inactivity Timer. This value must be the same for all routers attached to a common network. The default value is 40 seconds. The interval range is 1 to 65535. -.. cfgcmd:: set interfaces <inttype> <intname> ip ospf hello-interval <number> +.. cfgcmd:: set protocols ospf interface <interface> hello-multiplier <number> + + The hello-multiplier specifies how many Hellos to send per second, from 1 + (every second) to 10 (every 100ms). Thus one can have 1s convergence time + for OSPF. If this form is specified, then the hello-interval advertised in + Hello packets is set to 0 and the hello-interval on received Hello packets + is not checked, thus the hello-multiplier need NOT be the same across + multiple routers on a common link. + +.. cfgcmd:: set protocols ospf interface <interface> hello-interval <number> Set number of seconds for Hello Interval timer value. Setting this value, Hello packet will be sent every timer value seconds on the specified @@ -351,13 +360,18 @@ Interface Configuration common network. The default value is 10 seconds. The interval range is 1 to 65535. -.. cfgcmd:: set interfaces <inttype> <intname> ip ospf mtu-ignore +.. cfgcmd:: set protocols ospf interface <interface> bfd + + This command enables :abbr:`BFD (Bidirectional Forwarding Detection)` on + this OSPF link interface. + +.. cfgcmd:: set protocols ospf interface <interface> mtu-ignore This command disables check of the MTU value in the OSPF DBD packets. Thus, use of this command allows the OSPF adjacency to reach the FULL state even though there is an interface MTU mismatch between two OSPF routers. -.. cfgcmd:: set interfaces <inttype> <intname> ip ospf network <type> +.. cfgcmd:: set protocols ospf interface <interface> network <type> This command allows to specify the distribution type for the network connected to this interface: @@ -368,14 +382,14 @@ Interface Configuration networks. **point-to-point** – address distribution in point-to-point networks. -.. cfgcmd:: set interfaces <inttype> <intname> ip ospf priority <number> +.. cfgcmd:: set protocols ospf interface <interface> priority <number> This command sets Router Priority integer value. The router with the highest priority will be more eligible to become Designated Router. Setting the value to 0, makes the router ineligible to become Designated Router. The default value is 1. The interval range is 0 to 255. -.. cfgcmd:: set interfaces <inttype> <intname> ip ospf retransmit-interval +.. cfgcmd:: set protocols ospf interface <interface> retransmit-interval <number> This command sets number of seconds for RxmtInterval timer value. This @@ -383,7 +397,7 @@ Interface Configuration Request packets if acknowledge was not received. The default value is 5 seconds. The interval range is 3 to 65535. -.. cfgcmd:: set interfaces <inttype> <intname> ip ospf transmit-delay <number> +.. cfgcmd:: set protocols ospf interface <interface> transmit-delay <number> This command sets number of seconds for InfTransDelay value. It allows to set and adjust for each interface the delay interval before starting the |
