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1841 config problems?



I'm a newbie on Routers and Cisco matter. I had been trying to set up a 1841 but I have several problems.

I have a network with a 2921 as Gateway and router for a hosted application subnet 10.20.0.X, also I have on the same network a 1841(a) for my email an internet. All this is a temporal connection. I'm setting now my primary connection with another 1841(b), I'll take out the router (a) from the network and just leave router (b) with the same IP address than router a for the LAN. I can't access router 2921, it's not mine.

On my tests, I used the router 1841(b) to test the primary connection for internet and email it works perfect. I can open pages so fast, and I'm receiveing emails. For those test I put on the router address When I made the swap address on the router b, I put on the router b the address that belongs to router a and just unplug the router a from the network.

At this point, the router b still routing fine the emails but the internet come so slow and just open few pages, like google, gmail, xo, but it doesn't open cisco, godaddy, ebay, yahoo and others.

Any idea where will be the problem? In advance thank you for any help.

2 Replies 2

Glenn Quesenberry
Cisco Employee
Cisco Employee

This Community forum is designed for the Cisco Small Business router series.  Your question will be best served and answered in the larger Cisco WAN routing & Switching community.  That is where you can locate information for the 18XX & 29XX router series rather than here.

Best Regards,

(Per your suggestion I have moved this thread in the Wan, routing and switching area - regards, Cindy)

Message was edited by: Cindy Toy, Cisco Small Business Support Community Manager

Richard Burts
Hall of Fame
Hall of Fame

There might be several issues that could impact you:

- if you unplug 1841A and configure 1841B with the same address now that address is associated with a different MAC address. If some devices have cached the MAC address in their ARP table they would have problems in communicating with the new 1841. This would be a temporary problem and would resolve itself as devices flush their ARP cache (depending on the length of their ARP timer).

- the symptoms that you describe might be caused by the need to fragment traffic to and from the Internet.

- it is possible that the limited traffic volume of your test was fine but that the full volume of your production traffic is saturating your new Internet connection. Can you tell us what kind of connection was your temporary connection and what kind of circuit is the new connection?

It might help us to figure things out if you would post the config from your 1841 (protecting passwords and any other sensitive information).




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