We have a Cisco 3845 router with OSPF running on GRE interface Tunnels (nb : 88).
There are also GRE/IPSEC interface tunnels (nb 88) with no routing protocol running on them. The pysical support is VSAT.
We encountered 3 times high CPU utilisation (above 90%) related to the OSPF process in a period of 3 weeks). Each time, it happened about 15 minutes after a large number of GRE/IPSEC tunnel interfaces went down in a small interval (a few-seconds).
IOS is 24-15.T3.
Here is the configuration of a GRE/IPSEC interface :
description *** VTI VPN VSAT Secours Ag 47 ***
ip address 172.23.47.1 255.255.255.0
keepalive 5 3
tunnel source 192.168.231.2
tunnel destination 172.25.47.2
tunnel mode ipsec ipv4
tunnel protection ipsec profile VTI-PROFILE
Any idea what is going wrong ?
Thank you in advance.