I recently purchased my first cisco router and am using it at home with my new att dsl in san francisco. Up unitl now, I’ve used simple routers like entry level models from Linksys and Netgear. I switched to this basic cisco router hoping for better stability. Unfortunately, I’m having trouble configuring it.
The Router is a SB101 running IOS 12.4(10). I use SDM GUI to configure it. My problem relates to obtaining the IP address and gateway from the ATT dsl modem. When I set my interface Ethernet1 to “obtain an ip address automatically”, it fails to obtain an ip address. When I set it to a static ip, and enter it myself, the router runs fine.
I’m able to find out my assigned ip address by connecting my laptop directly to the dsl modem. The laptop, unlike the router, is able to obtain the assigned ip without any problem. Once I see what the laptop’s assigned ip is, i just reconnect the router to the modem and enter the fixed address for the router. This works fine until the dsl modem gets a new ip address and my router, with the fixed ip entered, does not get updated.
When I switch the router from fixed to dynamic ip, the only field it asks me for (in the sdm gui) is a isp’s hostname for dhcp. It says this is optional and I don’t have it (so i leave it blank). Perhaps this is a mistake. Perhaps my problem is something else. I read something about changing the maximum packet size (related to att dsl issues) but I don’t see this setting in my SDM GUI.
Can anyone help?