router 2501

[WINSQLIIS]

could you tell me how do I configure two network on the same interface?
I have Cisco 2501 router and it has only one ethernet interface. I am trying to assign a scond network to the same interface and route the two networks.
please help if you can, I am looking for the command I can use.

 

[hexn]

This is an interesting situation, and there really is no solution.

You can assign a secondary IP address to an ethernet interface like so:

ip address 10.0.0.1 255.0.0.0 secondary

However, you will find that you cant route between the primary and secondary interfaces, but they will both work as gateways.

Perhaps Cisco implmented that to FORCE you to buy a router with more ethernet interfaces.

So YES you can assign more than 1 IP or network to an interface, but NO you cannot route between them.

Unless the later versions of IOS have fixed such a thing. If anyone knows anyway around this, I would love to know.

 

[IPKONFIG]

It's called routing on a stick. But you can only do that with fast ethernet ports, which your 2501 does not have. I'd suggest that you purchase a 2514 from E-Bay at $800/router. That will give you 2 ethernet ports and your home LAN will be set. The routing on a stick was first developed for vlans, and is used with caching engines. You can read all about "routing on a stick" at

http://www.cisco.com/univercd/cc/td/doc/product/webscale/webcache/ce17/ver17/wc17plan.htm#3813

Enjoy.

 

[wybnormal]

Well.. both are right... but lets clarify a few things.

Secondary interfaces work very well but have some limits in routing as was pointed out.

As far as the router on a stick goes, that is for trunking of VLANs over a single interface in order to have the router route between the vlans. And you need a 2620 or a 2621 router(fastethernet) but the 2610/11 can do 802.1q (no ISL) over the 10 1/2 port assuming you have the right IOS load. When you configure the vlans over the ethernet interface, you configure something called "sub-interfaces".. it would look something like this:

interface fastethernet 0/0.2

Notice the 0.2 ? that is the second subinterface on port fa0/0 Each subinterface is it's own logical interface and treated as a physical interface by the router.

As you can see, there are all kinds of choices.

MikeS
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