configuring same subnet cisco 3640 router

[jsantiago]

Hello:

I have a 3640 router with 4 wic-1dsu-t1 cards to connect 4 remote offices. The problem I'm having is that I need to have on the 3640 the same subnet on the fastethernet side in order to connect the 4 remote offices to my LAN. Every time I configure more than one fastethernet with the same subnet I get an overlap error. Can any one help.

[thisisshanky]

You cannot configure the same subnet address to multiple interfaces of a router (any router). Not understanding your requirement, Why are you trying to configure four addresses from the same subnet to four different FastE's ?

[jsantiago]

The reason I want to configure the same subnet is for the fastethernets to see my LAN. If I configure more than one fethernet with the same subnet I get an overlap error. I have tried using the IP Unnumbered command but this only works for serial interfaces. Is there a way to have fethernet under the same subnet? Any help.

[mark-obrien]

Shanky's correct, there is no way to have the same subnet on more than one interface. What do you mean by having these fastethernets "see" your LAN?

[dbellazetin]

It sounds like you are trying to bridge your offices together so that basically it looks like one giant flat network is that correct? So in every site the ip addresses will be in the same subnet? If this is the case than configure your 3640 to as a bridge and you will probably need to do this on all your remote site routers too.

If this is NOT what you are trying to do please be more descriptive in the over all goal that is to be accomplished.

config t

no ip routing

bridge 1 protocol ieee

int fa 0/0

no ip add

bridge-group 1

int fa 0/1

no ip add

bridge-group 1

int fa 0/2

no ip add

bridge-group 1

int fa 0/3

no ip add

bridge-group 1

int s 0/0

no ip add

bridge-group 1

int s 0/1

no ip add

bridge-group 1

int s 0/2

no ip add

bridge-group 1

int s 0/3

no ip add

bridge-group 1

end

wr mem