Configure the Anycast IP Gateway Router

Before you begin

  • Create the VLAN.
  • Configure an IP address for the VLAN.
  • Create the Layer 2 I-SID.
  • Map the customer VLAN to the I-SID.
  • Optionally, if you associate the VLAN with a VRF (Layer 3 VSN), enable IP-VPN on that VRF.

About this task

Anycast IP Gateway routers advertise the configured routing interfaces, including the gateway MAC addresses and the gateway IP addresses. Associate the routing interfaces with Layer 2 VSNs, and configure each Anycast IP Gateway-enabled interface with a gateway IP and a gateway MAC.

Procedure

  1. Enter VLAN Interface Configuration mode:

    enable

    configure terminal

    interface vlan <1–4059>

  2. Optional: Add the interface to a Layer 3 VSN:
    vrf WORD<1-16>
    Note

    Note

    If you do not specify a VRF, the interface is added in the GRT.
  3. Configure the gateway IP and a gateway MAC:
    ip anycast-gateway {A.B.C.D} [vrid <1-255>]
  4. Enable Anycast IP Gateway on the VLAN:
    ip anycast-gateway enable
  5. Display the routable MAC entry for the gateway MAC:
    show vlan mac-address-entry <1-4059>
  6. Display the local ARP entry for the gateway IP and the gateway MAC:
    show ip arp vlan <1-4059>
  7. Display the static gateway MAC entry:
    show i-sid mac-address-entry <1-4059>

Example

Configure Anycast IP Gateway on VLAN 10, assuming all necessary prerequisites are complete:

Switch:1>enable
Switch:1#configure terminal
Enter configuration commands, one per line.  End with CNTL/Z.
Switch:1(config)#interface vlan 10
Switch:1(config-if)#ip anycast-gateway 192.0.2.254
Switch:1(config-if)#ip anycast-gateway enable
Switch:1(config-if)#exit
Switch:1(config)#show vlan mac-address-entry 10
========================================================================
                         Vlan Fdb
========================================================================
VLAN            MAC                               SMLT
ID    STATUS    ADDRESS            INTERFACE      REMOTE   TUNNEL
------------------------------------------------------------------------
10    self      00:00:5e:00:01:27  Port-mgmt      false    -
10    self      d8:84:66:f6:dd:01  Port-cpp       false    -
c: customer vid   u: untagged-traffic
2 out of 2 entries in all fdb(s) displayed.

Switch:1(config)#show i-sid mac-address-entry 10
===========================================================================================================
                                I-SID Fdb Table
===========================================================================================================
I-SID STATUS MAC-ADDRESS        INTERFACE TYPE  DEST-MAC          BVLAN DEST-SYSNAME AREA-ROLE AREA-NAME
-----------------------------------------------------------------------------------------------------------
10    self   00:00:5e:00:01:27  Port-mgmt LOCAL 00:00:00:00:00:00 0                  HOME      area-49.0010
10    self   d8:84:66:f6:dd:01  Port-cpp  LOCAL 00:00:00:00:00:00 0                  HOME      area-49.0010
c: customer vid   u: untagged-traffic
C: manually configured; D: discovered by FA or EPT
M: FA management; E: discovered by EAP; A: auto-sense
l: discover by local switch  r: discover by remote VIST switch
All 2 out of 2 Total Num of i-sid FDB Entries displayed

 
Switch:1(config)#show ip arp vlan 10
=============================================================================
                        IP Arp - GlobalRouter
=============================================================================
IP_ADDRESS      MAC_ADDRESS        VLAN  PORT     TYPE    TTL(10 Sec) TUNNEL
-----------------------------------------------------------------------------
192.0.2.15      d8:84:66:f6:dd:01  10    -        LOCAL   2160
192.0.2.254     00:00:5e:00:01:27  10    -        LOCAL   2160
192.0.2.255     ff:ff:ff:ff:ff:ff  10    -        LOCAL   2160
c: customer vid   u: untagged-traffic
3 out of 3 ARP entries displayed

Variable Definitions

The following table defines parameters for the ip anycast-gateway command.

Variable Value
A.B.C.D

Specifies the gateway IPv4 address. The gateway IP must be in different subnets for different interfaces, and must be the same on different routers for the same associated Layer 2 VSNs.

You can configure a different gateway IP from the VLAN IP, or as a One IP interface to use the same IP as the VLAN. For more information, see Create a One IP Anycast IP Gateway Interface.
enable Enables Anycast IP Gateway on the VLAN. The default is disabled.
vrid <1-255>

Specifies the virtual router ID, which defines the gateway MAC as a VRRP MAC. The gateway MAC must be the same on different routers for the same associated Layer 2 VSN.

If you do not specify the VRID as part of the command, the default value is VRID 39 (hexadecimal 27), which translates to the MAC of 00:00:5e:00:01:27.
9039040-00 Rev AB