Subject: Re: network interfaces(my fault)
To: Unix Wizard <>
From: Frederick Bruckman <>
List: netbsd-users
Date: 03/11/2001 15:10:57
> > You can't have two interfaces with the same address! In fact, you
> > can't even have two interfaces on the same machine on the same
> > network. How would it know which interface to send a packet out on?
> >
> > It's a bug that you were even be able to do that!
> >
> > Maybe if you tell us exactly what you're trying to accomplish (dhcp
> > client and gateway for a cable modem?), folks here could help you
> > design a network that makes sense.

On Sun, 11 Mar 2001, Unix Wizard wrote:
> Sorry Folks,
> I typed it by hand  output of the commands, duh?! Mistyped IP one ne2 in my
> e-mail.Accept my appologies..
> Okay correction
> IP for ne2
> IP for ne3

There's your problem! They're both on network 192.168.0/24, so how
can the router have both in the routing table, and if it did, how
would it know which one to use?

> It's going to be a GATEWAY, but for simplicity let's look at it as a regular
> workstation with 2 NIC's
> Connected to a switch. While ne2 is working, and ne3 is not.

Assuming that the external address is imposed by your cable modem,
just pick a different network for your internal interface (say,
192.168.100). "defaultroute" as defined in /etc/rc.conf or /etc/mygate
should remain on your external interface. By the way, if you didn't
know this already, all you have to do to enable the change is execute
"/etc/rc.d/network restart".

By the way, this discussion would be easier for others to follow if
you would quote judiciously, preserve the attributions, and have your
response _follow_ the text your responding to. [Top posting is for
MCSEE's and other mental defectives. :-)]