Cisco 7613 problem

Unanswered Question
Mar 4th, 2009

We are having 3 7613 Router and facing problem of high CPU .We are having 700 P2P GRE Tunnels in each Router. All of them are in OSPF.Most of the time the router CPU remains 80 to 90 %.In "Show Process Sorted " it shows that 40% of utilization is due to interrupt.Show run also makes the CPU to 100% and takes 20 to 30 second to get the output. Can anybody help me?

I have this problem too.
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Paolo Bevilacqua Wed, 03/04/2009 - 02:24

Wich SUP you have ? 700 ospf links may exceeded capabilities of the box, have you designed the network under cisco's recommendations /

Anupam Datta Thu, 03/05/2009 - 03:17

WE are using SUP 720. Earlier we were running with two 3845 box.But those box were not able to handle more. Cisco has did an audit lst year and recommended for this box in this environment and suggested for implementing MGre-DMVPN instead of P2P GRE.but the situation is very critical where we are not being able to terminate more than one TSP Backhaul VPN link in this box.If we put second VPN Backhaul link it remains 100 % constantly and the box stops traffic transmission. We are having Four TSP Bachaul VPN link where in each VPN, having approax 150 to 180 P2P GRE Tunnels.WE are worried that if the box is capable to handle those many GRE and OSPF or not?Secondly why Interrupt is taking so high CPU ?In One VPN Link with 180 GRE , the process is 70 to 80% Average , where as in a 3845 with same no of GRE and OSPF it is running with CPU 20 to 30 %.Last three months we are suffering for this and tried a lot to fix it but nothing worked.Can anybody tell me if there is any way forward.Another information -We have taken IPSec VPN SPA also .GRE's are acselerated by the VPN SPA without cryto or IPsec.Still it is the behaviour of the box.

Paolo Bevilacqua Thu, 03/05/2009 - 05:21

I think you need to involve Cisco again and get their design recommendation, like tiering the network, analyzing exactly where the CPU hits happens, etc.

Anupam Datta Thu, 03/05/2009 - 09:51

Yah, You are right.We are trying to involve Cisco for RCA. But one thing is not understandable to me,is that- Why 3845 running with 20 to 30 % ,in the same senario 7613 is going 70 to 80 %?What is the difference between 3845 and 7613 in-respect of handling OSPF & GRE ?Can anybody tell me that if we migrate it to Single AS iBGP instead of OSPF and eliminate GRE's by creating iBGP neighbors through WAN interfaces.Then it will work fine or not ? What is the maximum number of iBGP peers tested or recomended?


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