CSM reporting failed ARP request

Unanswered Question
Jun 7th, 2007
User Badges:


We have a CSM on Catalyst 6509 SUP720, the IOS is 12.2(18)SXD7b.

We have a problem with load-balanced portal servers with the CSM. Checking Catalyst log we see the following messages:

Jun 7 06:17:42.145 UTC: %CSM_SLB-6-RSERVERSTATE: Module 4 server state changed: SLB-NETMGT: Server [ip address] failed ARP request

Jun 7 06:17:43.505 UTC: %CSM_SLB-6-RSERVERSTATE: Module 4 server state changed: SLB-NETMGT: Server [ip address]now responding to ARP requests

Jun 7 06:19:23.445 UTC: %CSM_SLB-6-GATEWAYSTATE: Module 4 gateway state changed: SLB-NETMGT: Gateway [ip address]failed ARP request

Jun 7 06:24:12.241 UTC: %CSM_SLB-6-GATEWAYSTATE: Module 4 gateway state changed: SLB-NETMGT: Gateway [ip address]now responding to ARP requests

At the begining, the message were on refer to failed ARP for the real servers, but now the CSM reports failed ARP request on the Gateways (Vlan Interfaces) too.

Any idea?? We don?t now if the problem is the network, or is the CSM Card or the IOS version.

The Catalyst 6500 is on Distribution Layer, connecting 4 Access switches (Enterasys) and 2 Core Cat6500 switches. The balanced servers are on a Access Enterasys N7 Switch.

Thanks in advance...


  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
Gilles Dufour Thu, 06/07/2007 - 11:45
User Badges:
  • Cisco Employee,

honestly, I do not think that's a csm issue.

Capture a portchannel trace and filter the arp messages.

See if the csm gets a response to its arp requests.

If not, find out why by sniffing at different places.


PEDRO AGUIRRE Fri, 06/08/2007 - 07:36
User Badges:

Hi Gilles, thanks for your quick response.

But, as well as the problem with missing ARP?s, we have very slow responses and sites pages are shown with missing objets every time we point to the CSM virtual address with 2 internet proxi servers on a CSM Serverfarm, while if we point to the Real IP Address of any proxi-sever, all is fine and fast.

Now we are pointing directly to real servers (not to the CSM virtual), and all is fine, but it is not the final idea.

It sounds like a problem with the Channel betwen the CSM and the Switch.

We made traces monitoring the PortChannel 260, and we saw very ARP request but just a few replys.

Is very strange that also the CSM is reporting missing ARP?s on Gateways, because this gateway is an interface Vlan into the MSFC!! The only way to disappear the log missing ARP messages is configuring static arp on CSM.

What you think about?.

The version on CSM is 4.2(2)




This Discussion