Subject: problems with interface aliases.
To: None <tech-net@NetBSD.ORG>
From: Mike Mestnik <mmestnik@visi.com>
List: tech-net
Date: 10/20/2006 16:41:16
An old article, but an unanswered one.

http://mail-index.netbsd.org/tech-net/1997/08/24/0000.html

The fix for broadcast pkts is to pass the netmask and broadcast
options.  I have not tested this and there is no way to set the ?unused?
NetworkID.

I have a bigger problem.  I am setting up two systems with identical
IPs for HA reasons.  Doing this prevents them from communication as
they once have, I'm ok with this.

Both systems are on different networks and both have different network
IDs.  123.89.89.89/24 and 123.24.24.24/24.  After adding the aliases
123.24.24.24/32 and 123.89.89.89/32 respectfully.  I add their alter egos
and put something in /etc/hosts so we can still use there names for
things like ssh, 123.89.89.90/32 and 123.24.24.25/32.

Darn, outgoing connections will not come from the alter ego as is
needed.  I put these routes in place, but no go.  Why is this not
working like a multi-homed setup?  Should I get another ethernet
connection to the same network?

# 123.89.89.0/24	123.89.89.89
# default		123.89.89.1
123.89.89.90		123.89.89.1
123.24.24.25		123.89.89.90

# 123.24.24.0/24	123.24.24.24
# default		123.24.24.1
123.24.24.25		123.24.24.1
123.89.89.90		123.24.24.25

Vary wicked and vary not functional.
Should have the effect I have previously seen in multi-homed setups
where the originating IP is taken, indirectly, from the route used
(123.89.89.0/24 and 123.24.24.0/24).

I think I have it, I'm just messing things up some how.  tcpdump is
not showing outbound on the one interface, there is no route to lo in
the path AFAICT.  What should I be looking for?

4.11-RELEASE FreeBSD

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