Cisco 1700 Problems

Nov 17, 2005 5 Replies
J

Hello everybody, long time listener.. first time caller hehehe. Anyway, I am IT manager for a small company. we recently had AT&T put in a full data T-1, they put a managed Cisco 1700 in and won't let us manage it at all. We recently began having a problem where internet access all but dissapears. The only recourse is to re-boot the router. AT&T looked at it and said the memory was full. Well this is now happening about every 4-8 hours. Very frustrating. AT&T seems stumped, and we are obviously frustrated. We only have about 15-20 users in the office, the router is doing NAT translation. I have one dude who uses Limewire all day... could this be causing the problem?



Jerry



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N

Without a config file there is not a lot to base a decision on. The Memory full sounds like BS to me, Unless your limewire user is allowing a large amout of connections or you have more that one P2P user. See if AT&T will give you a read only SNMP password so you can pull the config and then you can also use some monitoring tools to monitor the router. You can download from Solarwinds a toolkit and use the 30 Day eval version until you resolve your issue. If they wont give you the RO password you are stuck at taking their word for it and your best bet is to hammer them with the Service Level Agreement. Make them give you a solution. Also a router is no substitute for a good firewall. You might consider removing NAT from the router and putting in a small firewall. Netscreen or Sonicwall are good options for a small office. This would allievate most of the proscessing for the router and put you back in control of Internet access.

Good luck with AT&T

snipped-for-privacy@yahoo.com

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E

I have seen 1721 routers unable to timely expire old NAT entries due to buggy IOS.

An work-around was to tweak the timeout timers to very low values.

The final fix was to replace the IOS.

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J

Is there any way this could be related to settings on my local DNS server? I thought lookups were going kinda slow, and made some changes to the DNS settings on the LAN adapter on my DNS server, putting in some addresses of AT&T's external servers in a hope to speed up lookups. The problem came around shortly after. This morning I set it back the way it was, and all seems so far so good...

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J

Did you add the AT&T DNS servers as forwarders? i.e. if you local DNS server(s) cannot resolve the address, then and only then they would forward the request to AT&T's dns servers? If not, you may be overwhelming the router with DNS traffic.

John

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M

One easy way to consume hugh amount of router memory is to point default to an interfface instead of next hope. Ask AT&T to show you how they configured the default route on the managed router

ip route 0.0.0.0 0.0.0.0 ! this is the correct way

ip route 0.0.0.0 0.0.0.0 ! this is NOT good

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