Default router issue

So I have a strange issue with my 1841. I'm using it in a very simple scenario (home router on DSL line).

For some reason the router of last resort only gets set if I set FastEthernet0/1 address via dhcp. If I set it statically and then set router of last resort it doesn't show in show run config.

Anyone seen something like this? Is it a known bug in a slightly outdated version of IOS?

ROM: System Bootstrap, Version 12.3(8r)T6, RELEASE SOFTWARE (fc1)

I haven't read through all of the release notes for later versions of IOS. Is that where I should look to see bug notices or is there some place else I should check for that?

Thanks!

Charles

Reply to
Charles N Wyble
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If you set the Fa0/1 address manually are you also setting a default route? If not then there won't be one. A DHCP server will usually provide a default gateway as well as an IP address (as well a whole bunch of other stuff).

Sam

Reply to
Sam Wilson

Sam is right on point, if you are not running a routing protocol with the provider (which is never done on Residential service), then you router is getting its default gateway from the DHCP process. DHCP can provide many extra fields beyond an IP and Subnet Mask, such as DNS servers, default gateways, and tftp servers. As soon as you set a static, you must provide these variables on your own to each node on that same subnetwork (in this case, probably only your router, and DNS/ TFTP are probably not needed).

Reply to
Trendkill

Ah good point. I set the gateway but not the default route.

If not then there won't be one. A DHCP server will usually

Yes I know that. :) I have configured many DHCP servers/setups.

Thanks for the insight!

Charles

Reply to
Charles N Wyble

You may know this as well, but "ip default-gateway" isn't the same as a default route - IIRC it's only used when the box isn't configured as a router.

Sam

Reply to
Sam Wilson

Right.... that makes sense.

- IIRC it's only used when the box isn't configured as a

As far as I can tell, its used when the router isn't the last hop. I could be wrong though. :)

Charles

Reply to
Charles N Wyble

I don't think that's right. "ip default-gateway" is used when the box isn't being a router: either it's a switch and not a router at all, or you have a router being a bridge, or at least not an IP router, or during flash load helper (where a run-from-flash box is running a stripped down IOS while replacing the main IOS code).

Sam

Reply to
Sam Wilson

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