Create a One IP Anycast IP Gateway Interface

Before you begin

  • Create 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 and configure a CLIP interface in the VRF.

About this task

Configure the interface as a One IP interface, which means the gateway IP is the same as the VLAN IP. 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.

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 one-ip {A.B.C.D/X} [vrid <1-255>] [<0-511>]
  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. Verify that the local ARP entry is installed with the VLAN MAC address:
    show ip arp vlan <1-4059>

Example

Configure a One IP interface on VLAN 11, 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 11
Switch:1(config-if)#ip anycast-gateway one-ip 198.0.2.254/24
Switch:1(config-if)#ip anycast-gateway enable
Switch:1(config-if)#exit
Switch:1(config)#show vlan mac-address-entry 11
========================================================================
                         Vlan Fdb
========================================================================
VLAN            MAC                               SMLT
ID    STATUS    ADDRESS            INTERFACE      REMOTE   TUNNEL
-----------------------------------------------------------------------------
11    self      00:00:5e:00:01:27  Port-mgmt      false    -
11    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 11
===========================================================================================================
                                I-SID Fdb Table
===========================================================================================================
I-SID STATUS MAC-ADDRESS        INTERFACE TYPE  DEST-MAC          BVLAN DEST-SYSNAME AREA-ROLE AREA-NAME
-----------------------------------------------------------------------------------------------------------
11    self   00:00:5e:00:01:27  Port-mgmt LOCAL 00:00:00:00:00:00 0                  HOME      area-49.0010
11    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 11 
=============================================================================
                        IP Arp - VRF testvrf
=============================================================================
IP_ADDRESS    MAC_ADDRESS        VLAN  PORT     TYPE    TTL(10 Sec) TUNNEL
-----------------------------------------------------------------------------
198.0.2.254   d8:84:66:f6:dd:01    11    -      LOCAL   2160
198.0.2.255   ff:ff:ff:ff:ff:ff    11    -      LOCAL   2160
c: customer vid   u: untagged-traffic
2 out of 2 ARP entries displayed

Variable Definitions

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

Variable Value
<0-511> Specifies a number by which to offset the MAC address from the chassis MAC address. This ensures that each IP address has a different MAC address. If you omit this variable, a unique MAC offset is automatically generated.
A.B.C.D/X

Specifies the gateway IPv4 address and subnet mask. 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.
enable Enables Anycast IP Gateway on the VLAN. The default is disabled.
vrid <1-255>

Specifies 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