Cisco IP address Unnumbered...

[UnixSkunk]

Hi, all..I'm curious if anyone knows if it is possible to set up an unnumbered interface on an Ethernet interface? To be exact, I have 2 ethernet interfaces, and I want to do this..

interface Ethernet1/0
ip address 10.0.0.2 255.255.255.192

interface Ethernet1/1
ip unnumbered Ethernet1/0

It keeps telling me the following...
Point-to-point (non-multi-access) interfaces only

I know there is still a vast amount I dont know about Ciscos. Does anyone have a suggestion for how I can make this work? Can I make this work?

Many thanks.


UnixSkunk - Not everything is black and white.

 

[jneiberger]

I will use a phrase that I learned from one of my mentors: What problem are you trying to solve?

 

[UnixSkunk]

I have a Cisco router with 5 interfaces. 0/0, 1/0, 1/1, 1/2, 1/3.

I only have 5 IP addresses. I'm trying to setup 1/0 with an IP address. I want to setup 1/1 as IP unnumbered to save a static IP address. And I want to setup one of the interfaces as a NAT'd interface.

Someone set my remote site up so its Networkdrop -> Switch -> Router. I'm trying to figure out how to reconfigure the router so its Networkdrop -> Router -> Switch, which is the way it should be.

Thanks again.


UnixSkunk - Not everything is black and white.

 

[jneiberger]

You could probably do this with IRB, integrated routing and bridging. You'd create a Bridge Virtual Interface and then move the IP address from your current ethernet interface over to the BVI. Then you bridge the two ethernet interfaces together.

I haven't had time to really think this through, though, so proceed at your own risk. Look up IRB on Cisco's site to get the configuration details. It's pretty simple to setup and may allow you to do what you're trying to do.

 

[JOAMON]

Are four of the ports switch ports on a HWIC?

 

[KiscoKid]

You can't run unnumbered on ethernet interfaces (or any multi-access interface for that matter). You can only run it on point to point interfaces.

 

[UnixSkunk]

Many thanks to everyone who responded. We eventually just started running DHCP, and NAT on the router, and assigned it its own 192.168 address at one of the inside interfaces. Everything seems to work pretty well after that.

UnixSkunk - Not everything is black and white.