[c-nsp] bridgeing /dhcp problems

[Roy]

Steven Lamb wrote:
> I am new to this forum and not very seasoned with Cisco equip. I am the 
> Systems Admin of a small Iowa ISP we have recently had to had the capability 
> of OC3 to our network so that we can carry enough bandwidth. for this 
> purpose we purchased a Cisco 7120 OC3  Router off of eBay. the equipment 
> seems to work as best I can tell. It is currently running version 12.3 of 
> the IOS. More info available in the Config that I have also posted.
>
> here is what I have going on currently on our network.
>
> we have one rack of servers connected to a hub as well as 2 Cisco routers 
> ( a 2620 and the new7120) currently the 2620 will handle all of the outbound 
> traffic until we can switch people over to the new Router.
>
> here is the scenario I am having problems with. The teleco I work with has I 
> believe a teliant 5000 that they are handing off to me via fiber a point to 
> point vc which carries a single DSL customer. I take that vc on a sub 
> interface of my OC3 interface which is in a bridge group. when the OC3 was 
> the only interface in the bridge group I was unable to ping the rest of my 
> router from the DSL modem, so I added the FE port to the bridge this allows 
> a statically assigned machine off of the modem to ping and get to the rest 
> of the world. however the problem I am running into is when they try to 
> DHCP. some times I get a quick response from my DHCP server and some times I 
> get a slow response 2+ min. also regardless of how long it takes for the 
> DHCP to come back sometimes the modem will not know how to get out to the 
> rest of the world. I don't really know what to check or change to resolve 
> these two problems. what info other than the config would be useful to see?
>
>
> ...
>
>
>   
You should be using RBE instead of IRB. 

http://www.cisco.com/en/US/tech/tk175/tk817/tsd_technology_support_protocol_home.html