Re: IP aliasing

[Patrick Welche <prlw1%cam.ac.uk@localhost>]

On Wed, Jun 18, 2008 at 10:00:10AM -0400, DAve wrote:
> Good morning,
>
> I have been told by my Network Administrator that we will be changing IP  
> blocks for several key services very soon. I have three new DNS servers  
> running NetBSD on the new IP block already. I also have two legacy DNS  
> servers (also on NetBSD) that I need to drag along behind me for a few  
> more months.
>
> My new IP block is 65.124.104.X and my old IP block is 65.196.224.X. Is  
> it possible to have a single machine answer for both IPs on a single  
> interface? The network Gods claim they can route the traffic to me no  
> problem, but I am unsure how to configure the alias for the interface.
>
> Old address: 65.196.224.2
> Netmask: 255.255.255.0
> Gateway: 65.196.224.1
>
> New address: 65.124.104.25
> Netmask: 255.255.255.224
> Gateway: 65.124.104.1
>
> Is it even possible to alias the old address with the new gateway?

        ifconfig if0 inet 65.124.104.25 netmask 255.255.255.224
        ifconfig if0 inet 65.196.224.2 netmask 255.255.255.0 alias

should do the trick? (replacing if0 with bge0 wm0 nfe0 or whatever you have)

Your gateway is a specific router, so what is its ip number? 65.124.104.1?

        route change default 65.124.104.1

for the outbound traffic?

Cheers,

Patrick