We are running HSRP between a RSM and a 4700 router. The RSM is routing all our VLANs, and the 4700 handles all our ISDN lines.
We are running MRTG to monitor these routers, and we found that the CPU utilization on the 4700 tend to mirror that of the RSM, ie. If the RSM's CPU goes up to 15%, the 4700's will go up to 15% as well.
To me, this sounds wrong. If the RSM routes all the VLANs, then surely the 4700 will just cruise almost all day long?
We had the case recently where the RSM's CPU went up to 100%, but we couldn't find the process that was killing the CPU!! Needless to say, the 4700 followed soon. After the RSM was rebooted, it stayed at below 10% CPU, and the 4700 gradually went down as well.
Any thoughts on what it could be that can kill a RSM like that (and, of course, the HSRP issue)?
Do you have the HSRP active side set to the RSM ? If the standby router is actually the rsm and not the isdn router than all your traffic would be routed out the isdn side and then back over to the RSM side . Are you tracking a serial interface to make it fallover and then have a default route pointing towards the isdn side ?
Thanks for the replies! HSRP is active on the RSM, and on standby on the 4700. Both routers are actually our LAN routers (except for the 4700 which does ISDN as well), and both have exactly the same VLANs configured on them.
I have double checked to make sure that all VLANs are active on the RSM, and standby on the 4700.
I am actually using MRTG to monitor the CPU utilization of these routers - no other interfaces are monitored...
[toc:faq]The ProblemOn traditional switches whenever we have a trunk
interface we use the VLAN tag to demultiplex the VLANs. The switch needs
to determine which MAC Address table to look in for a forwarding
decision. To do this we require the switch to do...
[toc:faq]Introduction:Netdr is a tool available on a RSP720, Sup720 or
Sup32 that allows one to capture packets on the RP or SP inband. The
netdr command can be used to capture both Tx and Rx packets in the
software switching path. This is not a substitut...
IntroductionOSPF, being a link-state protocol, allows for every router
in the network to know of every link and OSPF speaker in the entire
network. From this picture each router independently runs the Shortest
Path First (SPF) algorithm to determine the b...