.. _services: Services ======== DHCP ---- Multiple DHCP Servers can be run from a single machine. Each DHCP service is identified by a `shared-network-name`. DHCP Server Example ^^^^^^^^^^^^^^^^^^^ In this example, we are offering address space in the 172.16.17.0/24 network, which is on eth1, and pppoe0 is our connection to the internet. We are using the network name `dhcpexample`. Prerequisites ^^^^^^^^^^^^^ Configuring the PPPoE interface is assumed to be done already, and appears on `pppoe0` Interface Configuration ^^^^^^^^^^^^^^^^^^^^^^^ .. code-block:: sh set interface eth1 address 172.16.17.1/24 Multiple ranges can be defined and can contain holes. .. code-block:: sh set service dhcp-server shared-network-name dhcpexample authoritative set service dhcp-server shared-network-name dhcpexample subnet 172.16.17.0/24 default-router 172.16.17.1 set service dhcp-server shared-network-name dhcpexample subnet 172.16.17.0/24 dns-server 172.16.17.1 set service dhcp-server shared-network-name dhcpexample subnet 172.16.17.0/24 lease 86400 set service dhcp-server shared-network-name dhcpexample subnet 172.16.17.0/24 range 0 start 172.16.17.100 set service dhcp-server shared-network-name dhcpexample subnet 172.16.17.0/24 range 0 stop 172.16.17.199 Failover ^^^^^^^^ VyOS provides support for DHCP failover: .. code-block:: sh set service dhcp-server shared-network-name 'LAN' subnet '192.168.0.0/24' failover local-address '192.168.0.1' set service dhcp-server shared-network-name 'LAN' subnet '192.168.0.0/24' failover name 'foo' set service dhcp-server shared-network-name 'LAN' subnet '192.168.0.0/24' failover peer-address '192.168.0.2' .. note:: `name` must be identical on both sides! The primary and secondary statements determines whether the server is primary or secondary .. code-block:: sh set service dhcp-server shared-network-name 'LAN' subnet '192.168.0.0/24' failover status 'primary' or .. code-block:: sh set service dhcp-server shared-network-name 'LAN' subnet '192.168.0.0/24' failover status 'secondary' .. note:: In order for the primary and the secondary DHCP server to keep their lease tables in sync, they must be able to reach each other on TCP port 647. If you have firewall rules in effect, adjust them accordingly. Static mappings MAC/IP ^^^^^^^^^^^^^^^^^^^^^^ .. code-block:: sh set service dhcp-server shared-network-name dhcpexample subnet 172.16.17.0/24 static-mapping static-mapping-01 ip-address 172.16.17.10 set service dhcp-server shared-network-name dhcpexample subnet 172.16.17.0/24 static-mapping static-mapping-01 mac-address ff:ff:ff:ff:ff:ff Explanation ^^^^^^^^^^^ * :code:`set service dhcp-server shared-network-name dhcpexample authoritative` This says that this device is the only DHCP server for this network. If other devices are trying to offer DHCP leases, this machine will send 'DHCPNAK' to any device trying to request an IP address that is not valid for this network. * :code:`set service dhcp-server shared-network-name dhcpexample subnet 172.16.17.0/24 default-router 172.16.17.1` This is a configuration parameter for the subnet, saying that as part of the response, tell the client that I am the default router for this network * :code:`set service dhcp-server shared-network-name dhcpexample subnet 172.16.17.0/24 dns-server 172.16.17.1` This is a configuration parameter for the subnet, saying that as part of the response, tell the client that I am the DNS server for this network. If you do not want to run a DNS server, you could also provide one of the public DNS servers, such as google's. You can add multiple entries by repeating the line. * :code:`set service dhcp-server shared-network-name dhcpexample subnet 172.16.17.0/24 lease 86400` Assign the IP address to this machine for 24 hours. It is unlikely you'd need to shorten this period, unless you are running a network with lots of devices appearing and disappearing. * :code:`set service dhcp-server shared-network-name dhcpexample subnet 172.16.17.0/24 start 172.16.17.100 stop 172.16.17.199` Make the IP Addresses between .100 and .199 available for clients. DHCPv6 server ------------- VyOS provides DHCPv6 server functionality which is described in this section. In order to use the DHCPv6 server it has to be enabled first: .. code-block:: sh set service dhcpv6-server To restart the DHCPv6 server (operational mode): .. code-block:: sh restart dhcpv6 server To show the current status of the DHCPv6 server use: .. code-block:: sh show dhcpv6 server status Show statuses of all assigned leases: .. code-block:: sh show dhcpv6 server leases DHCPv6 server options ^^^^^^^^^^^^^^^^^^^^^ DHCPv6 server preference value ****************************** Clients receiving advertise messages from multiple servers choose the server with the highest preference value. The range for this value is `0...255`. Set a preference value for the DHCPv6 server: .. code-block:: sh set service dhcpv6-server preference Delete a preference: .. code-block:: sh set service dhcpv6-server preference Show current preference: .. code-block:: sh show service dhcpv6-server preference Specify address lease time ************************** The default lease time for DHCPv6 leases is 24 hours. This can be changed by supplying a `default-time`, `maximum-time` and `minimum-time` (all values in seconds): .. code-block:: sh set service dhcpv6-server shared-network-name subnet lease-time {default | maximum | minimum } Reset the custom lease times: .. code-block:: sh delete service dhcpv6-server shared-network-name subnet lease-time {default | maximum | minimum} Show the current configuration: .. code-block:: sh show service dhcpv6-server shared-network-name subnet lease-time {default | maximum | minimum} Specify NIS domain ****************** A Network Information (NIS) domain can be set to be used for DHCPv6 clients: .. code-block:: sh set service dhcpv6-server shared-network-name subnet nis-domain To Delete the NIS domain: .. code-block:: sh delete service dhcpv6-server shared-network-name subnet nis-domain Show a configured NIS domain: .. code-block:: sh show service dhcpv6-server shared-network-name subnet nis-domain Specify NIS+ domain ******************* The procedure to specify a Network Information Service Plus (NIS+) domain is similar to the NIS domain one: .. code-block:: sh set service dhcpv6-server shared-network-name subnet nisplus-domain To Delete the NIS+ domain: .. code-block:: sh delete service dhcpv6-server shared-network-name subnet nisplus-domain Show a configured NIS domain: # show service dhcpv6-server shared-network-name subnet nisplus-domain Specify NIS server address ************************** To specify a NIS server address for DHCPv6 clients: .. code-block:: sh set service dhcpv6-server shared-network-name subnet nis-server Delete a specified NIS server address: .. code-block:: sh delete service dhcpv6-server shared-network-name subnet nis-server Show specified NIS server addresses: .. code-block:: sh show service dhcpv6-server shared-network-name subnet nis-server Specify NIS+ server address *************************** To specify a NIS+ server address for DHCPv6 clients: .. code-block:: sh set service dhcpv6-server shared-network-name subnet nisplus-server Delete a specified NIS+ server address: .. code-block:: sh delete service dhcpv6-server shared-network-name subnet nisplus-server Show specified NIS+ server addresses: .. code-block:: sh show service dhcpv6-server shared-network-name subnet nisplus-server Specify a SIP server address for DHCPv6 clients *********************************************** By IPv6 address ############### A Session Initiation Protocol (SIP) server address can be specified for DHCPv6 clients: .. code-block:: sh set service dhcpv6-server shared-network-name subnet sip-server-address Delete a specified SIP server address: .. code-block:: sh delete service dhcpv6-server shared-network-name subnet sip-server-address Show specified SIP server addresses: .. code-block:: sh show service dhcpv6-server shared-network-name subnet sip-server-address By FQDN ####### A name for SIP server can be specified: .. code-block:: sh set service dhcpv6-server shared-network-name subnet sip-server-name Delete a specified SIP server name: .. code-block:: sh delete service dhcpv6-server shared-network-name subnet sip-server-name Show specified SIP server names: .. code-block:: sh show service dhcpv6-server shared-network-name subnet sip-server-name Simple Network Time Protocol (SNTP) server address for DHCPv6 clients ********************************************************************* A SNTP server address can be specified for DHCPv6 clients: .. code-block:: sh set service dhcpv6-server shared-network-name subnet sntp-server-address Delete a specified SNTP server address: .. code-block:: sh delete service dhcpv6-server shared-network-name subnet sntp-server-address Show specified SNTP server addresses: .. code-block:: sh show service dhcpv6-server shared-network-name subnet sntp-server-address DHCPv6 address pools ^^^^^^^^^^^^^^^^^^^^ DHCPv6 address pools must be configured for the system to act as a DHCPv6 server. The following example describes a common scenario. Example 1: DHCPv6 address pool ****************************** A shared network named `NET1` serves subnet `2001:db8:100::/64` which is connected to `eth1`, a DNS server at `2001:db8:111::111` is used for name services. The range of the address pool shall be `::100` through `::199`. The lease time will be left at the default value which is 24 hours. .. code-block:: sh set service dhcpv6-server shared-network-name NET1 subnet 2001:db8:100::/64 address-range start 2001:db8:100::100 stop 2001:db8:100::199 set service dhcpv6-server shared-network-name NET1 subnet 2001:db8:100::/64 name-server 2001:db8:111::111 Commit the changes and show the configuration: .. code-block:: sh commit show service dhcpv6-server shared-network-name NET1 { subnet 2001:db8:100::/64 { address-range { start 2001:db8:100::100 { stop 2001:db8:100::199 } } name-server 2001:db8:111::111 } } Static mappings ^^^^^^^^^^^^^^^ In order to map specific IPv6 addresses to specific hosts static mappings can be created. The following example explains the process. Example 1: Static IPv6 MAC-based mapping **************************************** IPv6 address `2001:db8:100::101` shall be statically mapped to a device with MAC address `00:15:c5:b7:5e:23`, this host-specific mapping shall be named `client1`. .. note:: The MAC address identifier is defined by the last 4 byte of the MAC address. .. code-block:: sh set service dhcpv6-server shared-network-name NET1 subnet 2001:db8:100::/64 static-mapping client1 ipv6-address 2001:db8:100::101 set service dhcpv6-server shared-network-name NET1 subnet 2001:db8:100::/64 static-mapping client1 identifier c5b75e23 Commit the changes and show the configuration: .. code-block:: sh show service dhcp-server shared-network-name NET1 shared-network-name NET1 { subnet 2001:db8:100::/64 { name-server 2001:db8:111::111 address-range { start 2001:db8:100::100 { stop 2001:db8:100::199 { } } static-mapping client1 { ipv6-address 2001:db8:100::101 identifier c5b75e23 } } } DHCP Relay ---------- If you want your router to forward DHCP requests to an external DHCP server you can configure the system to act as a DHCP relay agent. The DHCP relay agent works with IPv4 and IPv6 addresses. All interfaces used for the DHCP relay must be configured. See https://wiki.vyos.net/wiki/Network_address_setup. DHCP relay example ^^^^^^^^^^^^^^^^^^ .. figure:: _static/images/service_dhcp-relay01.png :scale: 80 % :alt: DHCP relay example DHCP relay example In this example the interfaces used for the DHCP relay are eth1 and eth2. The router receives DHCP client requests on eth1 and relays them through eth2 to the DHCP server at 10.0.1.4. Configuration ^^^^^^^^^^^^^ Enable DHCP relay for eth1 and eth2: .. code-block:: sh set service dhcp-relay interface eth1 set service dhcp-relay interface eth2 Set the IP address of the DHCP server: .. code-block:: sh set service dhcp-relay server 10.0.1.4 The router should discard DHCP packages already containing relay agent information to ensure that only requests from DHCP clients are forwarded: .. code-block:: sh set service dhcp-relay relay-options relay-agents-packets discard Commit the changes and show the results: .. code-block:: sh commit show service dhcp-relay interface eth1 interface eth2 server 10.0.1.4 relay-options { relay-agents-packets discard } The DHCP relay agent can be restarted with: .. code-block:: sh restart dhcp relay-agent DHCPv6 relay example ^^^^^^^^^^^^^^^^^^^^ .. figure:: _static/images/service_dhcpv6-relay01.png :scale: 80 % :alt: DHCPv6 relay example DHCPv6 relay example In this example DHCPv6 requests are received by the router on eth1 (`listening interface`) and forwarded through eth2 (`upstream interface`) to the external DHCPv6 server at 2001:db8:100::4. Configuration ************* Set eth1 to be the listening interface for the DHCPv6 relay: .. code-block:: sh set service dhcpv6-relay listen-interface eth1 Set eth2 to be the upstream interface and specify the IPv6 address of the DHCPv6 server: .. code-block:: sh set service dhcpv6-relay upstream-interface eth2 address 2001:db8:100::4 Commit the changes and show results: .. code-block:: sh commit show service dhcpv6-relay listen-interface eth1 { } upstream-interface eth2 { address 2001:db8:100::4 } Show the current status of the DHCPv6 relay agent: .. code-block:: sh show dhcpv6 relay-agent status The DHCPv6 relay agent can be restarted with: .. code-block:: sh restart dhcpv6 relay-agent Additional parameters ^^^^^^^^^^^^^^^^^^^^^ DHCP relay agent options ************************ Set the maximum hop count before packets are discarded. Range 0...255, default 10. * :code:`set service dhcp-relay relay-options hop-count 'count'` Set maximum size of DHCP packets including relay agent information. If a DHCP packet size surpasses this value it will be forwarded without appending relay agent information. Range 64...1400, default 576. * :code:`set service dhcp-relay relay-options max-size 'size'` Set the port used to relay DHCP client messages. Range 1...65535, default 67. After setting a different port, requests are still accepted on port 67 but replies are forwarded to 255.255.255.255 port 0 instead of 68. * :code:`set service dhcp-relay relay-options port 'port'` Four policies for reforwarding DHCP packets exist: * **append:** The relay agent is allowed to append its own relay information to a received DHCP packet, disregarding relay information already present in the packet. * **discard:** Received packets which already contain relay information will be discarded. * **forward:** All packets are forwarded, relay information already present will be ignored. * **replace:** Relay information already present in a packet is stripped and replaced with the router's own relay information set. * :code:`set service dhcp-relay relay-options relay-agents-packet 'policy'` DHCPv6 relay agent options ************************** Set listening port for DHCPv6 requests. Default: 547. * :code:`set service dhcpv6-relay listen-port 'port'` Set maximum hop count before packets are discarded. Default: 10. * :code:`set service dhcpv6-relay max-hop-count 'count'` If this is set the relay agent will insert the interface ID. This option is set automatically if more than one listening interfaces are in use. * :code:`set service dhcpv6-relay use-interface-id-option` DNS Forwarding -------------- Use DNS forwarding if you want your router to function as a DNS server for the local network. There are several options, the easiest being 'forward all traffic to the system DNS server(s)' (defined with set system name-server): .. code-block:: sh set service dns forwarding system Manually setting DNS servers for forwarding: .. code-block:: sh set service dns forwarding name-server 8.8.8.8 set service dns forwarding name-server 8.8.4.4 Manually setting DNS servers with IPv6 connectivity: .. code-block:: sh set service dns forwarding name-server 2001:4860:4860::8888 set service dns forwarding name-server 2001:4860:4860::8844 Setting a forwarding DNS server for a specific domain: .. code-block:: sh set service dns forwarding domain example.com server 192.0.2.1 Example 1 ^^^^^^^^^ Router with two interfaces eth0 (WAN link) and eth1 (LAN). A DNS server for the local domain (example.com) is at 192.0.2.1, other DNS requests are forwarded to Google's DNS servers. .. code-block:: sh set service dns forwarding domain example.com server 192.0.2.1 set service dns forwarding name-server 8.8.8.8 set service dns forwarding name-server 8.8.4.4 set service dns forwarding listen-on 'eth1' Example 2 ^^^^^^^^^ Same as example 1 but with additional IPv6 addresses for Google's public DNS servers: .. code-block:: sh set service dns forwarding domain example.com server 192.0.2.1 set service dns forwarding name-server 8.8.8.8 set service dns forwarding name-server 8.8.4.4 set service dns forwarding name-server 2001:4860:4860::8888 set service dns forwarding name-server 2001:4860:4860::8844 set service dns forwarding listen-on 'eth1' Dynamic DNS ----------- VyOS is able to update a remote DNS record when an interface gets a new IP address. In order to do so, VyOS includes ddclient_, a perl script written for this exact purpose. ddclient_ uses two methods to update a DNS record. The first one will send updates directly to the DNS daemon, in compliance with RFC2136_. The second one involves a third party service, like DynDNS.com or any other similar website. This method uses HTTP requests to transmit the new IP address. You can configure both in VyOS. VyOS CLI and RFC2136 ^^^^^^^^^^^^^^^^^^^^ First, create an RFC2136_ config node : .. code-block:: sh edit service dns dynamic interface eth0 rfc2136 Present your RNDC key to ddclient : .. code-block:: sh set key /config/dyndns/mydnsserver.rndc.key Set the DNS server IP/FQDN : .. code-block:: sh set server dns.mydomain.com Set the NS zone to be updated : .. code-block:: sh set zone mydomain.com Set the records to be updated : .. code-block:: sh set record dyn set record dyn2 You can optionally set a TTL (note : default value is 600 seconds) : .. code-block:: sh set ttl 600 This will generate the following ddclient config blocks: .. code-block:: sh server=dns.mydomain.com protocol=nsupdate password=/config/dyndns/mydnsserver.rndc.key ttl=600 zone=mydomain.com dyn server=dns.mydomain.com protocol=nsupdate password=/config/dyndns/mydnsserver.rndc.key ttl=600 zone=mydomain.com dyn2 You can also keep a different dns zone updated. Just create a new config node: .. code-block:: sh edit service dns dynamic interface eth0 rfc2136 VyOS CLI and HTTP dynamic DNS services ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ VyOS is also able to use any service relying on protocols supported by ddclient. To use such a service, you must define a login, a password, one or multiple hostnames, a protocol and a server. .. code-block:: sh edit service dns dynamic interface eth0 service HeNet set login my-login # set password my-password set host-name my-tunnel-id set protocol dyndns2 set server ipv4.tunnelbroker.net VyOS is also shipped with a list of known services. You don't need to set the protocol and server value as VyOS has defaults provided for those. These are the services VyOS knows about: * afraid * changeip * dnspark * dslreports * dyndns * easydns * namecheap * noip * zoneedit To use DynDNS for example: .. code-block:: sh edit service dns dynamic interface eth0 service dyndns set login my-login set password my-password set host-name my-dyndns-hostname It's possible to use multiple services : .. code-block:: sh edit service dns dynamic interface eth0 service dyndns set login my-login set password my-password set host-name my-dyndns-hostname edit service dns dynamic interface eth0 service HeNet set login my-login set password my-password set host-name my-tunnel-id set protocol dyndns2 set server ipv4.tunnelbroker.net ddclient behind NAT ^^^^^^^^^^^^^^^^^^^ By default, ddclient will update a dynamic dns record using the IP address directly attached to the interface. If your VyOS instance is behind NAT, your record will be updated to point to your internal IP. ddclient_ has another way to determine the WAN IP address. This is controlled by these two options: .. code-block:: sh set service dns dynamic interface eth0 use-web url set service dns dynamic interface eth0 use-web skip ddclient_ will load the webpage at `[url]` and will try to extract an IP address for the response. ddclient_ will skip any address located before the string set in `[skip]`. LLDP ---- The Link Layer Discovery Protocol (LLDP) is a vendor-neutral link layer protocol in the Internet Protocol Suite used by network devices for advertising their identity, capabilities, and neighbors on an IEEE 802 local area network, principally wired Ethernet.[1] The protocol is formally referred to by the IEEE as Station and Media Access Control Connectivity Discovery specified in IEEE 802.1AB and IEEE 802.3-2012 section 6 clause 79. LLDP performs functions similar to several proprietary protocols, such as `Cisco Discovery Protocol`_, `Foundry Discovery Protocol`_, Nortel Discovery Protocol and Link Layer Topology Discovery. Information gathered ^^^^^^^^^^^^^^^^^^^^ Information gathered with LLDP is stored in the device as a management information database (MIB_) and can be queried with the Simple Network Management Protocol (SNMP_) as specified in RFC 2922. The topology of an LLDP-enabled network can be discovered by crawling the hosts and querying this database. Information that may be retrieved include: * System name and description * Port name and description * VLAN name * IP management address * System capabilities (switching, routing, etc.) * MAC/PHY information * MDI power * Link aggregation Configuration ^^^^^^^^^^^^^ * Enable service with: :code:`set service lldp` Options ******* * Configure a Define management-address: :code:`set service lldp management-address ` * Define listening interfaces :code:`set service lldp interface ` * LLDPd also implements an SNMP subagent. To Enable SNMP queries of the LLDP database: :code:`set service lldp snmp enable` * Enable optional/other protocols :code:`set service lldp legacy-protocols cdp` Supported legacy protocols: * ``cdp`` - Listen for CDP for Cisco routers/switches * ``edp`` - Listen for EDP for Extreme routers/switches * ``fdp`` - Listen for FDP for Foundry routers/switches * ``sonmp`` - Listen for SONMP for Nortel routers/switches Display neighbors ^^^^^^^^^^^^^^^^^ * Display with: ``show lldp neighbors`` Exemple: .. code-block:: sh vyos@vyos:~# show lldp neighbors Capability Codes: R - Router, B - Bridge, W - Wlan r - Repeater, S - Station D - Docsis, T - Telephone, O - Other Device ID Local Proto Cap Platform Port ID --------- ----- ----- --- -------- ------- swA309 eth0 LLDP ? Cisco IOS Software, GigE0/33 * Options: * ``detail`` - Show lldp neighbors detail * ``interface`` - Show LLDP for specified interface Troubleshooting ^^^^^^^^^^^^^^^ Use operationnal command ``show log lldp`` to display logs. mDNS Repeater ------------- Starting with VyOS 1.2 a `Multicast DNS`_ (mDNS) repeater functionality is provided. Multicast DNS uses the 224.0.0.51 address, which is "administratively scoped" and does not leave the subnet. It re-broadcast mDNS packets from one interface to other interfaces. This enables support for e.g. Apple Airplay devices across multiple VLANs. To enable mDNS repeater you need to configure at least two interfaces. To re- broadcast all mDNS packets from `eth0` to `eth1` and vice versa run: .. code-block:: sh set service mdns repeater interface eth0 set service mdns repeater interface eth1 mDNS repeater can be temporarily disabled without deleting the service using .. code-block:: sh set service mdns repeater disable .. note:: You can not run this in a VRRP setup, if multiple mDNS repeaters are launched in a subnet you will experience the mDNS packet storm death! UDP broadcast relay ------------------- Certain vendors use broadcasts to identify their equipemnt within one ethernet segment. Unfortunately if you split your network with multiple VLANs you loose the ability of identifying your equiment. This is where "UDP broadcast relay" comes into play! It will forward received broadcasts to other configured networks. Every UDP port which will be forward requires one unique ID. Currently we support 99 IDs! Example #1: To forward all broadcast packets received on `UDP port 1900` on `eth3`, `eth4` or `eth5` to all other interfaces in this configuration. .. code-block:: sh set service broadcast-relay id 1 description 'SONOS' set service broadcast-relay id 1 interface 'eth3' set service broadcast-relay id 1 interface 'eth4' set service broadcast-relay id 1 interface 'eth5' set service broadcast-relay id 1 port '1900' Example #2: To Forward all broadcasts packets received on `UDP port 6969` on `eth3` or `eth4` to the other interface in this configuration. .. code-block:: sh set service broadcast-relay id 2 description 'SONOS MGMT' set service broadcast-relay id 2 interface 'eth3' set service broadcast-relay id 2 interface 'eth4' set service broadcast-relay id 2 port '6969' Disable Instance(s) ^^^^^^^^^^^^^^^^^^^ Each broadcast relay instance can be individually disabled without deleting the configured node by using the following command: .. code-block:: sh set service broadcast-relay id disable In addition you can also disable the whole service without removing the configuration by: .. code-block:: sh set service broadcast-relay disable .. note:: You can run the UDP broadcast relay service on multiple routers connected to a subnet. There is **NO** UDP broadcast relay packet storm! SNMP ---- Simple Network Management Protocol (SNMP_) is an Internet Standard protocol for collecting and organizing information about managed devices on IP networks and for modifying that information to change device behavior. Devices that typically support SNMP include cable modems, routers, switches, servers, workstations, printers, and more. SNMP is widely used in network management for network monitoring. SNMP exposes management data in the form of variables on the managed systems organized in a management information base (MIB_) which describe the system status and configuration. These variables can then be remotely queried (and, in some circumstances, manipulated) by managing applications. Three significant versions of SNMP have been developed and deployed. SNMPv1 is the original version of the protocol. More recent versions, SNMPv2c and SNMPv3, feature improvements in performance, flexibility and security. SNMP is a component of the Internet Protocol Suite as defined by the Internet Engineering Task Force (IETF). It consists of a set of standards for network management, including an application layer protocol, a database schema, and a set of data objects. Overview and basic concepts ^^^^^^^^^^^^^^^^^^^^^^^^^^^ In typical uses of SNMP, one or more administrative computers called managers have the task of monitoring or managing a group of hosts or devices on a computer network. Each managed system executes a software component called an agent which reports information via SNMP to the manager. An SNMP-managed network consists of three key components: * Managed devices * Agent – software which runs on managed devices * Network management station (NMS) – software which runs on the manager A managed device is a network node that implements an SNMP interface that allows unidirectional (read-only) or bidirectional (read and write) access to node-specific information. Managed devices exchange node-specific information with the NMSs. Sometimes called network elements, the managed devices can be any type of device, including, but not limited to, routers, access servers, switches, cable modems, bridges, hubs, IP telephones, IP video cameras, computer hosts, and printers. An agent is a network-management software module that resides on a managed device. An agent has local knowledge of management information and translates that information to or from an SNMP-specific form. A network management station executes applications that monitor and control managed devices. NMSs provide the bulk of the processing and memory resources required for network management. One or more NMSs may exist on any managed network. .. figure:: _static/images/service_snmp_communication_principles_diagram.png :scale: 20 % :alt: Principle of SNMP Communication Image thankfully borrowed from https://en.wikipedia.org/wiki/File:SNMP_communication_principles_diagram.PNG which is under the GNU Free Documentation License .. note:: VyOS SNMP supports both IPv4 and IPv6. SNMP protocol versions ^^^^^^^^^^^^^^^^^^^^^^ VyOS itself supports SNMPv2_ (version 2) and SNMPv3_ (version 3) where the later is recommended because of improved security (optional authentication and encryption). SNMPv2 ^^^^^^ SNMPv2 is the original and most commonly used version. For authorizing clients, SNMP uses the concept of communities. Communities may have authorization set to read only (this is most common) or to read and write (this option is not actively used in VyOS). SNMP can work synchronously or asynchronously. In synchronous communication, the monitoring system queries the router periodically. In asynchronous, the router sends notification to the "trap" (the monitoring host). SNMPv2 does not support any authentication mechanisms, other than client source address, so you should specify addresses of clients allowed to monitor the router. Note that SNMPv2 also supports no encryption and always sends data in plain text. Example ******* .. code-block:: sh # Define a community set service snmp community routers authorization ro # Allow monitoring access from the entire network set service snmp community routers network 192.0.2.0/24 set service snmp community routers network 2001::db8:ffff:eeee::/64 # Allow monitoring access from specific addresses set service snmp community routers client 203.0.113.10 set service snmp community routers client 203.0.113.20 # Define optional router information set service snmp location "UK, London" set service snmp contact "admin@example.com" # Trap target if you want asynchronous communication set service snmp trap-target 203.0.113.10 # Listen only on specific IP addresses (port defaults to 161) set service snmp listen-address 172.16.254.36 port 161 set service snmp listen-address 2001:db8::f00::1 SNMPv3 ^^^^^^ SNMPv3 is an updated version that, among other things, supports encryption and cryptographic authentication of clients. Example ******* .. code-block:: sh set service snmp v3 engineid '0x0aa0d6c6f450' set service snmp v3 group defaultgroup mode 'ro' set service snmp v3 group defaultgroup seclevel 'priv' set service snmp v3 group defaultgroup view 'defaultview' set service snmp v3 view defaultview oid '1' set service snmp v3 user testUser1 auth plaintext-key testUserKey1 set service snmp v3 user testUser1 auth type 'md5' set service snmp v3 user testUser1 engineid '0x0aa0d6c6f450' set service snmp v3 user testUser1 group 'defaultgroup' set service snmp v3 user testUser1 mode 'ro' set service snmp v3 user testUser1 privacy type aes set service snmp v3 user testUser1 privacy plaintext-key testUserKey1 After commit the resulting configuration will look like: .. note:: SNMPv3 keys won't we stored in plaintext. On ``commit`` the keys will be encrypted and the encrypted key is based on the engineid! .. code-block:: sh vyos@vyos# show service snmp v3 { engineid 0x0aa0d6c6f450 group defaultgroup { mode ro seclevel priv view defaultview } user testUser1 { auth { encrypted-key 0x3b68d4162c2c817b8e9dfb6f08583e5d type md5 } engineid 0x0aa0d6c6f450 group defaultgroup mode ro privacy { encrypted-key 0x3b68d4162c2c817b8e9dfb6f08583e5d type aes } } view defaultview { oid 1 { } } } TFTP ---- Trivial File Transfer Protocol (TFTP_) is a simple lockstep File Transfer Protocol which allows a client to get a file from or put a file onto a remote host. One of its primary uses is in the early stages of nodes booting from a local area network. TFTP has been used for this application because it is very simple to implement. Example ^^^^^^^ .. code-block:: sh # If you want to enable uploads, else TFTP server will act as read-only (optional) set service tftp-server allow-upload # Directory for TFTP server content set service tftp-server directory '/config/tftpboot' # On which addresses we want to listen for incoming TFTP connections? (mandatory) set service tftp-server listen-address '2001:db8:ffee::1' set service tftp-server listen-address '10.10.1.1' .. note:: Choose your ``directory`` location carefully or you will loose the content on image upgrades. Any directory under ``/config`` is save at this will be migrated. .. note:: Configuring a listen-address is essential for the service to work. The resulting configuration will look like: .. code-block:: sh vyos@vyos# show service tftp-server { allow-upload directory /config/tftpboot listen-address 2001:db8:ffee::1 listen-address 10.10.1.1 } .. _ddclient: http://sourceforge.net/p/ddclient/wiki/Home/ .. _RFC2136: https://www.ietf.org/rfc/rfc2136.txt .. _`Cisco Discovery Protocol`: https://en.wikipedia.org/wiki/Cisco_Discovery_Protocol .. _`Foundry Discovery Protocol`: https://en.wikipedia.org/wiki/Foundry_Discovery_Protocol .. _`Multicast DNS`: https://en.wikipedia.org/wiki/Multicast_DNS .. _SNMP: https://en.wikipedia.org/wiki/Simple_Network_Management_Protocol .. _SNMPv2: https://en.wikipedia.org/wiki/Simple_Network_Management_Protocol#Version_2 .. _SNMPv3: https://en.wikipedia.org/wiki/Simple_Network_Management_Protocol#Version_3 .. _MIB: https://en.wikipedia.org/wiki/Management_information_base .. _TFTP: https://en.wikipedia.org/wiki/Trivial_File_Transfer_Protocol