Unanswered Question
Jan 4th, 2009

My border router which is in the LAN, of late has started giving erratic ping(1000ms) and timeout yet it is just in the LAN after a reset it come to normal (ping response becomes an average 5ms)but when the traffic goes thro it ping response degrades.We use static ip routes, AL and NATing(sorry but am not allow to post the configs) any ideas why it is so. i have checked loop back configs but none. Any help will be appreciated

I have this problem too.
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Danilo Dy Sun, 01/04/2009 - 21:44

1. Check the interfaces along the path if there is accumulating packet drops (also check the settings). Chances are, it could be a duplex mismatch.

2. When the ping reach 1000ms, login to the router and check the cpu util. If its high, check which process is taking a lot of cpu time.

John Blakley Mon, 01/05/2009 - 10:15

If this is happening consistently, I would configure netflow on the router to see if you can determine what traffic is going through the router. You can then block that traffic to see if it helps your throughput.



da3angwenyi Mon, 01/05/2009 - 10:34

Thanks John but i have all kinds of traffic( from clients) flowing thro the router i just need to pin which IP, AL, or config is causing the mess.From the records the issue happens like thrice in a day each time i do a reset things are normal.

John Blakley Mon, 01/05/2009 - 10:39

Netflow would show you the IP, but if resetting the router fixes it, then personally I wouldn't suspect a host. Does it happen at the same time every day?

da3angwenyi Mon, 01/05/2009 - 10:47

Thanks i will try netflow tho i have never configured it, give me time i try my hands on a demo router then on the BR because its critical each reset causes an uproar. The issue happens depending on traffic flow. The higher the traffic the faster it times out. Will get back to you once am done.


Edison Ortiz Mon, 01/05/2009 - 13:18


As others have indicated, NetFlow will help you identify what device(s) is/are causing the high bandwidth utilization which in turn is causing high CPU on the router.

Can you tell us what type of router and WAN speed this router have?

You may need to implement some kind of QoS to prevent this kind of behavior from occurring.




da3angwenyi Mon, 01/05/2009 - 20:54

The router 7400ASR with 2 FastEthernet ports and 2 gig interfaces.thanks for overwhelming support


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