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New Member

871 router placement/config question

I just started supporting a small law office and they have an 871 router. I had to factory reset the router b/c no one there knew the passwords and getting into ROMMON was not working correctly. So, anyway here is the basic setup and my question. From what I can gather the router had the IP of, but I'm not sure what interface that was assigned to? The WAN or the VLAN?

Internet --> AT&T DSL router ---> Wan port on 871..........FE0---->LAN Switch

AT&T DSL router is

The DC on the LAN switch is

So, what interface do I assign the IP to?

  • WAN Routing and Switching
Hall of Fame Super Gold

Re: 871 router placement/config question

When you "break into" a router via config-register change, you will be able to boot with no configuration set, skip auto-install, and look at the confing previously in place with "show startup".

Anyway, that address likely goes on VLAN1.

New Member

Re: 871 router placement/config question

I did that and must've typed something wrong b/c when I changed the password I probably forgot to type copy start run before I did the copy run start. So, I'm back to square one with the router.

Thanks for the tip on IP placement.

Hall of Fame Super Gold

Re: 871 router placement/config question

I stand corrected, it is actually more likely that the address goes on Fa4.

But what is confusing is "dcd switch .253" that is the same subnet.

Also, for best perfornaces, you should set the ISP modem in bridge, so to receive a public IP on the 871.

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New Member

Re: 871 router placement/config question

And that's why I'm confused. I can't understand why they would have the IP's the way they do. private to private on both sides.

It makes no sense.

It's like he was using the router only for VPN connections?