You might think that EIGRP being around for so long is not getting any attention from
Cisco, not true. EIGRP is still being developed and in later releases you can run what
is called named configuration. Doing this you can put all EIGRP config under one named
instance, even v6 which is different from the old syntax. If you are on Twitter you should
follow Donnie Savage @diivious. He works for Cisco and is usually present at Cisco Live
presenting on the development of EIGRP.
We start out with the following topology.
So we start out by defining our instance and calling it corp
R2#conf t Enter configuration commands, one per line. End with CNTL/Z. R2(config)#router eigrp corp
From there we have the following options:
R2(config-router)#? Router configuration commands: address-family Enter Address Family command mode default Set a command to its defaults exit Exit from routing protocol configuration mode no Negate a command or set its defaults service-family Enter Service Family command mode shutdown Shutdown this instance of EIGRP
From here we can shutdown the process or configure different address families.
We start by setting up IPv4 in the global table.
R2(config-router)#address-family ipv4 autonomous-system 12 R2(config-router-af)#? Address Family configuration commands: af-interface Enter Address Family interface configuration default Set a command to its defaults eigrp EIGRP Address Family specific commands exit-address-family Exit Address Family configuration mode help Description of the interactive help system maximum-prefix Maximum number of prefixes acceptable in aggregate metric Modify metrics and parameters for address advertisement neighbor Specify an IPv4 neighbor router network Enable routing on an IP network no Negate a command or set its defaults shutdown Shutdown address family timers Adjust peering based timers topology Topology configuration mode R2(config-router-af)#network 184.108.40.206 255.255.255.0
From here we define networks, setup static neighbors and configure EIGRP parameters.
We will use regular syntax on R2 for setting up EIGRP.
R2(config-if)#router eigrp 12 R2(config-router)#no auto R2(config-router)#net 220.127.116.11 0.0.0.255
The session comes up.
%DUAL-5-NBRCHANGE: EIGRP-IPv4 12: Neighbor 18.104.22.168 (FastEthernet1/0) is up: new adjacency
R2 is announcing it’s loopback. Lets see if we receive that.
R1#sh ip route eigrp | be Gateway Gateway of last resort is not set 22.214.171.124/32 is subnetted, 1 subnets D 126.96.36.199 [90/2662400] via 188.8.131.52, 00:00:23, FastEthernet1/0
What more can we configure under the address-family?
R1(config-router-af)#af-interface f1/0 R1(config-router-af-interface)#? Address Family Interfaces configuration commands: authentication authentication subcommands bandwidth-percent Set percentage of bandwidth percentage limit bfd Enable Bidirectional Forwarding Detection dampening-change Percent interface metric must change to cause update dampening-interval Time in seconds to check interface metrics default Set a command to its defaults exit-af-interface Exit from Address Family Interface configuration mode hello-interval Configures hello interval hold-time Configures hold time next-hop-self Configures EIGRP next-hop-self no Negate a command or set its defaults passive-interface Suppress address updates on an interface shutdown Disable Address-Family on interface split-horizon Perform split horizon summary-address Perform address summarization
We configure all EIGRP interface commands under the af-interface. We can setup
authentication of the peering.
R1(config-router-af)#af-interface f1/0 R1(config-router-af-interface)#authentication mode ? hmac-sha-256 HMAC-SHA-256 Authentication md5 Keyed message digest R1(config-router-af-interface)#authentication mode md5 R1(config-router-af-interface)#authentication key-chain EIGRP %DUAL-5-NBRCHANGE: EIGRP-IPv4 12: Neighbor 184.108.40.206 (FastEthernet1/0) is down: authentication mode changed %DUAL-5-NBRCHANGE: EIGRP-IPv4 12: Neighbor 220.127.116.11 (FastEthernet1/0) is up: new adjacency
What’s new here is that sha-256 is now also supported. From this af-interface mode
we can configure timers and BFD as well.
Now we will configure IPv4 in a VRF called 13.
R1(config)#vrf definition 13 R1(config-vrf)#rd 13:13 R1(config-vrf)#int f1/1 R1(config-if)#no sh R1(config-if)#vrf forwarding 13 R1(config-if)#ip add 18.104.22.168 255.255.255.0 R1(config-router)#address-family ipv4 vrf 13 autonomous-system 13 R1(config-router-af)#net 22.214.171.124 0.0.0.255 %DUAL-5-NBRCHANGE: EIGRP-IPv4 13: Neighbor 126.96.36.199 (FastEthernet1/1) is up: new adjacency
Do we receive any prefixes?
R1#sh ip route vrf 13 | be Gate Gateway of last resort is not set 188.8.131.52/32 is subnetted, 1 subnets D 184.108.40.206 [90/2662400] via 220.127.116.11, 00:00:31, FastEthernet1/1 18.104.22.168/8 is variably subnetted, 2 subnets, 2 masks C 22.214.171.124/24 is directly connected, FastEthernet1/1 L 126.96.36.199/32 is directly connected, FastEthernet1/1
Which we do. Nothing strange here, just a new syntax for defining VRFs compared
to the old ip vrf syntax.
Finally we will configure IPv6 peering as well. Because EIGRP sends packets from
link local address we don’t even need to configure a global IPv6 address.
R1(config-router)#int f2/0 R1(config-if)#ipv6 enable R1(config-if)#no sh R1(config-if)#router eigrp corp R1(config-router)#address-family ipv6 autonomous-system 14 R1(config-router-af)#af-interface default R1(config-router-af-interface)#no shut
Only difference here is that instead of defining network we use the interface command
instead to enable it on all active IPv6 interfaces.
R1#sh ipv6 route eigrp IPv6 Routing Table - default - 2 entries Codes: C - Connected, L - Local, S - Static, U - Per-user Static route B - BGP, R - RIP, H - NHRP, I1 - ISIS L1 I2 - ISIS L2, IA - ISIS interarea, IS - ISIS summary, D - EIGRP EX - EIGRP external, ND - ND Default, NDp - ND Prefix, DCE - Destination NDr - Redirect, O - OSPF Intra, OI - OSPF Inter, OE1 - OSPF ext 1 OE2 - OSPF ext 2, ON1 - OSPF NSSA ext 1, ON2 - OSPF NSSA ext 2, l - LISP D 2001::/64 [90/2662400] via FE80::C803:82FF:FE80:1C, FastEthernet2/0
And that’s about it. Named configuration is made to unify configuration under
one instance and remove the commands that we used to type under the interface
like authentication and such. It’s now all done under the address-family.
In future posts I will look at Multi Topology Routing (MTR).