CUCM 8.6 running on VM getting alert KERNEL: assertion (!sk->sk_forward_alloc) failed at net/ipv4/af_inet.c (152)

[danterivera1]

Hi,

First time to post question here.

We have a CUCM 8.6 running in datacenter in Denver.  We have users located in 3 different sites, 1 in Watkins, 1 in Goldhill and the other one is in Canada.

Lately (past week) our users in Canada are experiencing difficulty in connecting to their VM, placing and receiving calls.  We checked the network and it looks clean.

No packet loss between Canada and the nexus.  The packet loss we are seeing are between the 10G link from Nexus to the VM.

We can see that the NIC running in VM is set to flexible.  We are also seeing this alert when we tried to login to VM...."KERNEL: assertion (!sk->sk_forward_alloc) failed at net/ipv4/af_inet.c (152).

We are thinking this could be the cause of the problem.  Any input would be greatly appreciated, thanks.

Regards,

Dante

[Manish Gogna]

Hi Dante,

This error is more of a cosmetic one as per the following bug

https://tools.cisco.com/bugsearch/bug/CSCts35326/?reffering_site=dumpcr

You should open a TAC case for issues with voicemail and calls. If you can provide some specific details about the exact issue like what type of calls are failing, frequency of failure, error message or announcement, IP phone models and firmware involved, call flow etc then someone might be able to respond on supportforums.

HTH

Manish

[danterivera1]

Hi mgogna,

Thanks very much for your reply.  I will try to collect further information.

Regards,

Dante

[rudyrajkumar]

Hi, did you find the root cause of this issue? We are seeing a similar problem which is affecting the client at a site level. We are seeing packet loss. The affected sites are fragmenting the REFER SIP message and we see that the first part of the fragmented packet (60 bytes) is being dropped consistently.

Thanks in advance!

[R0g22]

Where do you see the fragment drops ?

[rudyrajkumar]

We are working on getting captures setup on the Nexus 7k's. At the moment all we can say for sure is that the Nexus is receiving the correct packets and that it is being dropped before the physical NIC of the hosts.

FYI, CM is v9.1.2.16900-2 running on VMware 6.0

[rudyrajkumar]

Hi,

We have also determined that our 7k is receiving the packets from our WAN router and is dropping the packet on interface connecting to the UCS.

The specific packet is 60byte fragmented packet that is part of a SIP REFER message. This issue is only seen at sites that fragment the SIP REFER message.

Did you find a resolution to your problem?

Regards