EIGRP ***** DUAL The *Diffusing Update ALgorithm*, a *Bellman-Ford* based routing algorithm used by EIGRP. EIGRP -- Routing Information Protocol is widely deployed interior gateway routing protocol. EIGRP was developed in the 1990's. EIGRP is a *distance-vector* protocol and is based on the *DUAL* algorithms. As a distance-vector protocol, the EIGRP router send updates to its neighbors as networks change, thus allowing the convergence to a known topology. *eigrpd* supports EIGRP as described in RFC7868 Starting and Stopping eigrpd ============================ The default configuration file name of *eigrpd*'s is "eigrpd.conf". When invocation *eigrpd* searches directory /etc/frr. If "eigrpd.conf" is not there next search current directory. If an integrated config is specified configuration is written into "frr.conf". The EIGRP protocol requires interface information maintained by *zebra* daemon. So running *zebra* is mandatory to run *eigrpd*. Thus minimum sequence for running EIGRP is: # zebra -d # eigrpd -d Please note that *zebra* must be invoked before *eigrpd*. To stop *eigrpd*, please use :: kill *cat /var/run/eigrpd.pid* Certain signals have special meanings to *eigrpd*. +--------------------+-------------------------------------------------------------+ | Signal | Meaning | +====================+=============================================================+ | SIGHUP & SIGUSR1 | Rotate the log file | +--------------------+-------------------------------------------------------------+ | SIGINT & SIGTERM | Sweep all installed EIGRP routes and gracefully terminate | +--------------------+-------------------------------------------------------------+ *eigrpd* invocation options. Common options that can be specified (Common Invocation Options). EIGRP Configuration =================== router eigrp (1-65535) [vrf NAME] The *router eigrp* command is necessary to enable EIGRP. To disable EIGRP, use the *no router eigrp (1-65535)* command. EIGRP must be enabled before carrying out any of the EIGRP commands. Specify vrf NAME if you want eigrp to work within the specified vrf. no router eigrp (1-65535) [vrf NAME] Disable EIGRP. network NETWORK no network NETWORK Set the EIGRP enable interface by *network*. The interfaces which have addresses matching with *network* are enabled. This group of commands either enables or disables EIGRP interfaces between certain numbers of a specified network address. For example, if the network for 10.0.0.0/24 is EIGRP enabled, this would result in all the addresses from 10.0.0.0 to 10.0.0.255 being enabled for EIGRP. The *no network* command will disable EIGRP for the specified network. Below is very simple EIGRP configuration. Interface *eth0* and interface which address match to *10.0.0.0/8* are EIGRP enabled. ! router eigrp 1 network 10.0.0.0/8 ! passive-interface (IFNAME|default) no passive-interface IFNAME This command sets the specified interface to passive mode. On passive mode interface, all receiving packets are ignored and eigrpd does not send either multicast or unicast EIGRP packets except to EIGRP neighbors specified with *neighbor* command. The interface may be specified as *default* to make eigrpd default to passive on all interfaces. The default is to be passive on all interfaces. How to Announce EIGRP route =========================== redistribute kernel redistribute kernel metric (1-4294967295) (0-4294967295) (0-255) (1-255) (1-65535) no redistribute kernel *redistribute kernel* redistributes routing information from kernel route entries into the EIGRP tables. *no redistribute kernel* disables the routes. redistribute static redistribute static metric (1-4294967295) (0-4294967295) (0-255) (1-255) (1-65535) no redistribute static *redistribute static* redistributes routing information from static route entries into the EIGRP tables. *no redistribute static* disables the routes. redistribute connected redistribute connected metric (1-4294967295) (0-4294967295) (0-255) (1-255) (1-65535) no redistribute connected Redistribute connected routes into the EIGRP tables. *no redistribute connected* disables the connected routes in the EIGRP tables. This command redistribute connected of the interface which EIGRP disabled. The connected route on EIGRP enabled interface is announced by default. redistribute ospf redistribute ospf metric (1-4294967295) (0-4294967295) (0-255) (1-255) (1-65535) no redistribute ospf *redistribute ospf* redistributes routing information from ospf route entries into the EIGRP tables. *no redistribute ospf* disables the routes. redistribute bgp redistribute bgp metric (1-4294967295) (0-4294967295) (0-255) (1-255) (1-65535) no redistribute bgp *redistribute bgp* redistributes routing information from bgp route entries into the EIGRP tables. *no redistribute bgp* disables the routes. Show EIGRP Information ====================== show ip eigrp [vrf NAME] topology Display current EIGRP status. eigrpd> **show ip eigrp topology** # show ip eigrp topo EIGRP Topology Table for AS(4)/ID(0.0.0.0) Codes: P - Passive, A - Active, U - Update, Q - Query, R - Reply r - reply Status, s - sia Status P 10.0.2.0/24, 1 successors, FD is 256256, serno: 0 via Connected, enp0s3 show ip eigrp [vrf NAME] interface Display the list of interfaces associated with a particular eigrp instance. ..index:: show ip eigrp [vrf NAME] neighbor ..clicmd:: show ip eigrp [vrf NAME] neighbor Display the list of neighbors that have been established within a particular eigrp instance. EIGRP Debug Commands ==================== Debug for EIGRP protocol. debug eigrp packets Debug eigrp packets "debug eigrp" will show EIGRP packets that are sent and received. debug eigrp transmit Debug eigrp transmit events "debug eigrp transmit" will display detailed information about the EIGRP transmit events. show debugging eigrp Display *eigrpd*'s debugging option. "show debugging eigrp" will show all information currently set for eigrpd debug.