Router with 2 (or more) interfaces in same network

sthaug at sthaug at
Tue Nov 11 17:57:26 UTC 2003

> You _used_ to be able to do this (oh, over two years ago?). The address
> was assigned to the interface, and the error from trying to add a duplicate
> route was simply ignored, no route got added anywhere. You can figure out
> when the change was made by examining the code or by seeing when the 
> maillists started to get flooded by people who could no longer do,
>   # ifconfig if0 inet
>   # ifconfig if0 alias
> When they meant,
>   # ifconfig if0 inet
>   # ifconfig if0 alias netmask 0xffffffff

There is a difference, of course - Cisco is perfectly happy to let
you do

int fa0
 ip addr
 ip addr secondary

I never could understand why this should be impossible in FreeBSD.

But I guess this discussion is no longer NANOG relevant :-)

Steinar Haug, Nethelp consulting, sthaug at

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