Cisco 1841 with HWIC-4ESW - ARP issue

[lstegemann]

A c1841 router gets loosing hardware addresses of hosts connected to ports of a HWIC-4ESW module inserted. Port shut / no shut without result, only a reload solves the issue for some days or weeks. The router has been exchanged already, including HWIC module, as well as the 3COM LAN switch connecting the hosts to the router. Does anybody have similar experience or an idea how to proceed?

[Peter Paluch]

Hello,

Can you be more specific about the router "losing hardware addresses"? Do the addresses disappear from the show mac address-table or from the show ip arp? Does the problem result in connectivity issues? Is it also possible to show us your network topology, e.g. in a simple diagram?

Best regards,

Peter

[lstegemann]

Hello Peter,

First of all thanks for your response.

The hardware addresses disappear out of the >show ip arp< output, substituted by a statement >incomplete<.

If this happens to the backup router, this one enters the HSRP active state, like the primary one, and of cause no user can work any more.

Please have a look at my little network diagram attached, I tried to draw.

router-03: primary

router-04: backup

The IP .9 is the router hsrp address, the switch doesn't have any IP.

Kind regards,

Lothar

[cadet alain]

Hi,

Is this normal the standby group is not the same on both routers?

Can you post sanitized config of 2 routers. I don't see any mention about the switching module in your diagram

Regards.

Alain.

[lstegemann]

Hi Alain,

You hit me. A colleague of mine changed the standby group number for test while I took the output. Does the second arp output meet your reply? I also added some config files.

Btw: Similar configurations run successfully on several other locations. I don't have access to the customer LAN switch.

Regards,

Lothar