From ce090a4ced7fccce3fdc70142e22fa0009fae12b Mon Sep 17 00:00:00 2001 From: rebortg Date: Sun, 6 Dec 2020 21:41:10 +0100 Subject: arrange examples --- docs/configuration/vpn/dmvpn.rst | 335 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 335 insertions(+) create mode 100644 docs/configuration/vpn/dmvpn.rst (limited to 'docs/configuration/vpn/dmvpn.rst') diff --git a/docs/configuration/vpn/dmvpn.rst b/docs/configuration/vpn/dmvpn.rst new file mode 100644 index 00000000..d6706421 --- /dev/null +++ b/docs/configuration/vpn/dmvpn.rst @@ -0,0 +1,335 @@ +.. _vpn-dmvpn: + +##### +DMVPN +##### + +:abbr:`DMVPN (Dynamic Multipoint Virtual Private Network)` is a dynamic +:abbr:`VPN (Virtual Private Network)` technology originally developed by Cisco. +While their implementation was somewhat proprietary, the underlying +technologies are actually standards based. The three technologies are: + +* :abbr:`NHRP (Next Hop Resolution Protocol)` :rfc:`2332` +* :abbr:`mGRE (Multipoint Generic Routing Encapsulation)` :rfc:`1702` +* :abbr:`IPSec (IP Security)` - too many RFCs to list, but start with :rfc:`4301` + +NHRP provides the dynamic tunnel endpoint discovery mechanism (endpoint +registration, and endpoint discovery/lookup), mGRE provides the tunnel +encapsulation itself, and the IPSec protocols handle the key exchange, and +crypto mechanism. + +In short, DMVPN provides the capability for creating a dynamic-mesh VPN +network without having to pre-configure (static) all possible tunnel end-point +peers. + +.. note:: DMVPN only automates the tunnel endpoint discovery and setup. A + complete solution also incorporates the use of a routing protocol. BGP is + particularly well suited for use with DMVPN. + +.. figure:: /_static/images/vpn_dmvpn_topology01.png + :scale: 40 % + :alt: Baseline DMVPN topology + + Baseline DMVPN topology + +************* +Configuration +************* + +* Please refer to the :ref:`tunnel-interface` documentation for the individual + tunnel related options. + +* Please refer to the :ref:`ipsec` documentation for the individual IPSec + related options. + +.. cfgcmd:: set protocols nhrp tunnel cisco-authentication + + Enables Cisco style authentication on NHRP packets. This embeds the secret + plaintext password to the outgoing NHRP packets. Incoming NHRP packets on + this interface are discarded unless the secret password is present. Maximum + length of the secret is 8 characters. + +.. cfgcmd:: set protocols nhrp tunnel dynamic-map
+ nbma-domain-name + + Specifies that the :abbr:`NBMA (Non-broadcast multiple-access network)` + addresses of the next hop servers are defined in the domain name + nbma-domain-name. For each A record opennhrp creates a dynamic NHS entry. + + Each dynamic NHS will get a peer entry with the configured network address + and the discovered NBMA address. + + The first registration request is sent to the protocol broadcast address, and + the server's real protocol address is dynamically detected from the first + registration reply. + +.. cfgcmd:: set protocols nhrp tunnel holding-time + + Specifies the holding time for NHRP Registration Requests and Resolution + Replies sent from this interface or shortcut-target. The holdtime is specified + in seconds and defaults to two hours. + +.. cfgcmd:: set protocols nhrp tunnel map cisco + + If the statically mapped peer is running Cisco IOS, specify the cisco keyword. + It is used to fix statically the Registration Request ID so that a matching + Purge Request can be sent if NBMA address has changed. This is to work around + broken IOS which requires Purge Request ID to match the original Registration + Request ID. + +.. cfgcmd:: set protocols nhrp tunnel map nbma-address
+ + Creates static peer mapping of protocol-address to :abbr:`NBMA (Non-broadcast + multiple-access network)` address. + + If the IP prefix mask is present, it directs opennhrp to use this peer as a + next hop server when sending Resolution Requests matching this subnet. + + This is also known as the HUBs IP address or FQDN. + +.. cfgcmd:: set protocols nhrp tunnel map register + + The optional parameter register specifies that Registration Request should be + sent to this peer on startup. + + This option is required when running a DMVPN spoke. + +.. cfgcmd:: set protocols nhrp tunnel multicast + + Determines how opennhrp daemon should soft switch the multicast traffic. + Currently, multicast traffic is captured by opennhrp daemon using a packet + socket, and resent back to proper destinations. This means that multicast + packet sending is CPU intensive. + + Specfying nhs makes all multicast packets to be repeated to each statically + configured next hop. + + Synamic instructs to forward to all peers which we have a direct connection + with. Alternatively, you can specify the directive multiple times for each + protocol-address the multicast traffic should be sent to. + + .. warning:: It is very easy to misconfigure multicast repeating if you have + multiple NHSes. + +.. cfgcmd:: set protocols nhrp tunnel non-caching + + Disables caching of peer information from forwarded NHRP Resolution Reply + packets. This can be used to reduce memory consumption on big NBMA subnets. + + .. note:: Currently does not do much as caching is not implemented. + +.. cfgcmd:: set protocols nhrp tunnel redirect + + Enable sending of Cisco style NHRP Traffic Indication packets. If this is + enabled and opennhrp detects a forwarded packet, it will send a message to + the original sender of the packet instructing it to create a direct connection + with the destination. This is basically a protocol independent equivalent of + ICMP redirect. + +.. cfgcmd:: set protocols nhrp tunnel shortcut + + Enable creation of shortcut routes. + + A received NHRP Traffic Indication will trigger the resolution and + establishment of a shortcut route. + +.. cfgcmd:: set protocols nhrp tunnel shortcut-destination + + This instructs opennhrp to reply with authorative answers on NHRP Resolution + Requests destinied to addresses in this interface (instead of forwarding the + packets). This effectively allows the creation of shortcut routes to subnets + located on the interface. + + When specified, this should be the only keyword for the interface. + +.. cfgcmd:: set protocols nhrp tunnel shortcut-target
+ + Defines an off-NBMA network prefix for which the GRE interface will act as a + gateway. This an alternative to defining local interfaces with + shortcut-destination flag. + +.. cfgcmd:: set protocols nhrp tunnel shortcut-target
+ holding-time + + Specifies the holding time for NHRP Registration Requests and Resolution + Replies sent from this interface or shortcut-target. The holdtime is specified + in seconds and defaults to two hours. + +******* +Example +******* + + +This blueprint uses VyOS as the DMVPN Hub and Cisco (7206VXR) and VyOS as +multiple spoke sites. The lab was build using :abbr:`EVE-NG (Emulated Virtual +Environment NG)`. + +.. figure:: /_static/images/blueprint-dmvpn.png + :alt: DMVPN network + + DMVPN example network + +Each node (Hub and Spoke) uses an IP address from the network 172.16.253.128/29. + +The below referenced IP address `192.0.2.1` is used as example address +representing a global unicast address under which the HUB can be contacted by +each and every individual spoke. + +Configuration +============= + +Hub +--- + +.. code-block:: none + + set interfaces ethernet eth0 address 192.0.2.1/24 + + set interfaces tunnel tun100 address '172.16.253.134/29' + set interfaces tunnel tun100 encapsulation 'gre' + set interfaces tunnel tun100 local-ip '192.0.2.1' + set interfaces tunnel tun100 multicast 'enable' + set interfaces tunnel tun100 parameters ip key '1' + + set protocols nhrp tunnel tun100 cisco-authentication 'secret' + set protocols nhrp tunnel tun100 holding-time '300' + set protocols nhrp tunnel tun100 multicast 'dynamic' + set protocols nhrp tunnel tun100 redirect + set protocols nhrp tunnel tun100 shortcut + + set vpn ipsec esp-group ESP-HUB compression 'disable' + set vpn ipsec esp-group ESP-HUB lifetime '1800' + set vpn ipsec esp-group ESP-HUB mode 'tunnel' + set vpn ipsec esp-group ESP-HUB pfs 'dh-group2' + set vpn ipsec esp-group ESP-HUB proposal 1 encryption 'aes256' + set vpn ipsec esp-group ESP-HUB proposal 1 hash 'sha1' + set vpn ipsec esp-group ESP-HUB proposal 2 encryption '3des' + set vpn ipsec esp-group ESP-HUB proposal 2 hash 'md5' + set vpn ipsec ike-group IKE-HUB ikev2-reauth 'no' + set vpn ipsec ike-group IKE-HUB key-exchange 'ikev1' + set vpn ipsec ike-group IKE-HUB lifetime '3600' + set vpn ipsec ike-group IKE-HUB proposal 1 dh-group '2' + set vpn ipsec ike-group IKE-HUB proposal 1 encryption 'aes256' + set vpn ipsec ike-group IKE-HUB proposal 1 hash 'sha1' + set vpn ipsec ike-group IKE-HUB proposal 2 dh-group '2' + set vpn ipsec ike-group IKE-HUB proposal 2 encryption 'aes128' + set vpn ipsec ike-group IKE-HUB proposal 2 hash 'sha1' + + set vpn ipsec ipsec-interfaces interface 'eth0' + + set vpn ipsec profile NHRPVPN authentication mode 'pre-shared-secret' + set vpn ipsec profile NHRPVPN authentication pre-shared-secret 'secret' + set vpn ipsec profile NHRPVPN bind tunnel 'tun100' + set vpn ipsec profile NHRPVPN esp-group 'ESP-HUB' + set vpn ipsec profile NHRPVPN ike-group 'IKE-HUB' + +.. note:: Setting this up on AWS will require a "Custom Protocol Rule" for + protocol number "47" (GRE) Allow Rule in TWO places. Firstly on the VPC + Network ACL, and secondly on the security group network ACL attached to the + EC2 instance. This has been tested as working for the official AMI image on + the AWS Marketplace. (Locate the correct VPC and security group by navigating + through the details pane below your EC2 instance in the AWS console). + +Spoke +----- + +The individual spoke configurations only differ in the local IP address on the +``tun10`` interface. See the above diagram for the individual IP addresses. + +spoke01-spoke04 +^^^^^^^^^^^^^^^ + +.. code-block:: none + + crypto keyring DMVPN + pre-shared-key address 192.0.2.1 key secret + ! + crypto isakmp policy 10 + encr aes 256 + authentication pre-share + group 2 + crypto isakmp invalid-spi-recovery + crypto isakmp keepalive 30 30 periodic + crypto isakmp profile DMVPN + keyring DMVPN + match identity address 192.0.2.1 255.255.255.255 + ! + crypto ipsec transform-set DMVPN-AES256 esp-aes 256 esp-sha-hmac + mode transport + ! + crypto ipsec profile DMVPN + set security-association idle-time 720 + set transform-set DMVPN-AES256 + set isakmp-profile DMVPN + ! + interface Tunnel10 + ! individual spoke tunnel IP must change + ip address 172.16.253.129 255.255.255.248 + no ip redirects + ip nhrp authentication secret + ip nhrp map 172.16.253.134 192.0.2.1 + ip nhrp map multicast 192.0.2.1 + ip nhrp network-id 1 + ip nhrp holdtime 600 + ip nhrp nhs 172.16.253.134 + ip nhrp registration timeout 75 + tunnel source FastEthernet0/0 + tunnel mode gre multipoint + tunnel key 1 + ! + interface FastEthernet0/0 + ip address dhcp + duplex half + + +spoke05 +^^^^^^^ + +VyOS can also run in DMVPN spoke mode. + +.. code-block:: none + + set interfaces ethernet eth0 address 'dhcp' + + set interfaces tunnel tun100 address '172.16.253.133/29' + set interfaces tunnel tun100 local-ip 0.0.0.0 + set interfaces tunnel tun100 encapsulation 'gre' + set interfaces tunnel tun100 multicast 'enable' + set interfaces tunnel tun100 parameters ip key '1' + + set protocols nhrp tunnel tun100 cisco-authentication 'secret' + set protocols nhrp tunnel tun100 holding-time '300' + set protocols nhrp tunnel tun100 map 172.16.253.134/29 nbma-address '192.0.2.1' + set protocols nhrp tunnel tun100 map 172.16.253.134/29 register + set protocols nhrp tunnel tun100 multicast 'nhs' + set protocols nhrp tunnel tun100 redirect + set protocols nhrp tunnel tun100 shortcut + + set vpn ipsec esp-group ESP-HUB compression 'disable' + set vpn ipsec esp-group ESP-HUB lifetime '1800' + set vpn ipsec esp-group ESP-HUB mode 'tunnel' + set vpn ipsec esp-group ESP-HUB pfs 'dh-group2' + set vpn ipsec esp-group ESP-HUB proposal 1 encryption 'aes256' + set vpn ipsec esp-group ESP-HUB proposal 1 hash 'sha1' + set vpn ipsec esp-group ESP-HUB proposal 2 encryption '3des' + set vpn ipsec esp-group ESP-HUB proposal 2 hash 'md5' + set vpn ipsec ike-group IKE-HUB close-action 'none' + set vpn ipsec ike-group IKE-HUB ikev2-reauth 'no' + set vpn ipsec ike-group IKE-HUB key-exchange 'ikev1' + set vpn ipsec ike-group IKE-HUB lifetime '3600' + set vpn ipsec ike-group IKE-HUB proposal 1 dh-group '2' + set vpn ipsec ike-group IKE-HUB proposal 1 encryption 'aes256' + set vpn ipsec ike-group IKE-HUB proposal 1 hash 'sha1' + set vpn ipsec ike-group IKE-HUB proposal 2 dh-group '2' + set vpn ipsec ike-group IKE-HUB proposal 2 encryption 'aes128' + set vpn ipsec ike-group IKE-HUB proposal 2 hash 'sha1' + + set vpn ipsec ipsec-interfaces interface 'eth0' + + set vpn ipsec profile NHRPVPN authentication mode 'pre-shared-secret' + set vpn ipsec profile NHRPVPN authentication pre-shared-secret 'secret' + set vpn ipsec profile NHRPVPN bind tunnel 'tun100' + set vpn ipsec profile NHRPVPN esp-group 'ESP-HUB' + set vpn ipsec profile NHRPVPN ike-group 'IKE-HUB' + + -- cgit v1.2.3