HSRP Problems

[radiomen]

I have a problem with one customer, here is the issue.

Setup:

I have customer#1 with 2 LAN extensions (separate PVC’s) coming from a carrier xylan switch terminating on a 4006 switch on the same VLAN. The customer has 2 routers at their end and they are running HSRP on the LAN extension; everything works perfectly I can ping each router and the HSRP address as well.

Customer number#2 has one LAN extension coming from the same carrier Xylan switch terminating on the same 4006 with the same VLAN as customer #1.

Issue:

When I cross over the Xylan switch from the new customer#2 to the 4006, customer#1 HSRP address goes down, I can still ping each router for customer#1 but not the HSRP address.

As soon as I disconnect the LAN extension for customer#2 the HSRP starts working again for customer#1.

1. I tested customer#2 router on our network before delivery they where no problems what so ever with customer#1 HSRP.

2. I disable the router for customer#2 and as soon as I connect the carrier Xylan switch to our 4006 the same issue the HSRP goes down.

Note: I contact the carrier and they told me that their switches are configured properly in bridge mode. I tested this configuration using the same VLAN and the same settings etc etc, the only thing added now to the picture is the Xylan switch from the carrier.

Any suggestions will be appreciated.

Thank you.

[rais.ahmad]

Could this be your problem and solution?

Q. Can I configure more than one standby group with the same group number?

A. Yes. However, Cisco does not recommend it on lower-end platforms such as the 4x00 series and earlier. If the same group number is assigned to multiple standby groups, it creates a non-unique MAC address. This is seen as the router's own MAC address and it is filtered out if more than one router in a LAN becomes active. This behavior may change in future releases of Cisco IOS®.

Note: 4x00 series and earlier do not have the hardware required to support more than one MAC address at a time on Ethernet interfaces. However, the Cisco 2600 and Cisco 3600 do support multiple MAC addresses on all Ethernet and Fast Ethernet interfaces.

Thanks.

[kaustav.gupta]

Hi,

Are HSRP configured at ur 4k6 or cust end routers..

I cud not make out "When I cross over the Xylan switch from the new customer#2 to the 4006, customer#1 HSRP address goes down"

Cud u clarify

Regs

Kas

[radiomen]

Thanks for your reply,

The customer is running HSRP via 2 LAN extensions terminating on the same vlan. We are not running HSRP here.

As soon I connect the port from the xylan that’s when the problem begins

[kaustav.gupta]

Hi,

Can u provide me a detailed network diagram ...

regs

Kas

[radiomen]

Here it is. all routers are on the same vlan,

Even when i turn off the router from customer#2 and i plug in the cable from the carrier switch to the 4006 the hsrp goes down, L2 affecting L3 ????? THK.

[kaustav.gupta · Accepted solution]

Hi,

Can u make fa 2/17 member of a new VLAN .. Make the port live by connecting the Cust # 2 in the new VLAN and ping the HSRP IP

Regs

[radiomen]

I made a few changes, I move all the circuits to a new 4507 switch but the problem continued until I apply the access list to each of the interfaces from customer #1 to the 4507 switch. I only allow access for the customers router and subnet. And it work.

Thanks for your help.