EIGRP named configuration

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 12.12.12.0 255.255.255.0

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 12.12.12.0 0.0.0.255

The session comes up.

%DUAL-5-NBRCHANGE: EIGRP-IPv4 12: Neighbor 12.12.12.2 (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

      2.0.0.0/32 is subnetted, 1 subnets
D        2.2.2.2 [90/2662400] via 12.12.12.2, 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 12.12.12.2 (FastEthernet1/0) is down: authentication mode changed
%DUAL-5-NBRCHANGE: EIGRP-IPv4 12: Neighbor 12.12.12.2 (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 13.13.13.1 255.255.255.0
R1(config-router)#address-family ipv4 vrf 13 autonomous-system 13
R1(config-router-af)#net 13.13.13.0 0.0.0.255
%DUAL-5-NBRCHANGE: EIGRP-IPv4 13: Neighbor 13.13.13.3 (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

      3.0.0.0/32 is subnetted, 1 subnets
D        3.3.3.3 [90/2662400] via 13.13.13.3, 00:00:31, FastEthernet1/1
      13.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
C        13.13.13.0/24 is directly connected, FastEthernet1/1
L        13.13.13.1/32 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).