Issue with HSRP

[dfrane]

Hi All,

I have a problem with setting up HSRP with 2 routers and 1 L3 switch. For some reason, HSRP is failing to establish between the 2 routers. I've run debug standby on both routers and it looks like they're both sending their hello but are unable to see each other's message therefore electing themselves as "active" routers respectively. I've checked the configuration on all 3 devices prior and their connectivity, I don't seem to find any problem. I'm thinking that something is blocking the ICMP hellos from both routers. Hopefully, anyone can point out if I might've overlooked something. Thanks in advance! Please see attached file for the simple setup. 

Note: I'm using GNS3 as testing.

[pman]

I would recommend focusing on switch configuration.
First check if the switch sees the mac of the R1 and R2 Ethernet0/0 interface with 

show mac address

command.

You can see the mac of both R1 and R2 in interface Ethernet0/0 using

show interface Ethernet0/0

.

You may find it necessary to configure the switch interfaces that connected to R1 and R2 as switchport mode access

Additionally please post the output of 

show standby brief

 command from both R1 and R2,

and

show mac address-table

 from the switch.

Thanks.

[dfrane]

Both mac address of the routers are seen by the switch. I notice that R1's ARP entry on the switch is the virtual MAC of HSRP this is not true for R2. R2's ARP entry on the switch is the physical interface, although both switches are running HSRP. 

[Jon Marshall · Accepted solution]

On your switch try

no ip igmp snooping

. 

Jon

[dfrane]

Thank you very much Jon! i disabled this on the switch and ran debug and re-enabled the interface on active router participating in HSRP. they received each other's hello. 

[MHM Cisco World]

share

show interface brief

in both router and L3SW

[paul driver]

Hello

Make sure the port speed/duplex settings are correct between rtr and switchports and you can ping between the rtrs?

ping xxxx
sh interface

Also apply the following on the switchports
switch

int x/x
description link to rtr
switchport mode access
switchport access vlan 1
spanning-tree portfast
no shut

[Richard Burts]

The output of

show cdp neighbor

from all 3 devices might shed some light on this issue, particularly whether the devices see each other, and if so are they on the expected interfaces? 

It might also be helpful to see the output of

show interface status 

from the switch with an indication of which interfaces connect the switch to the routers.