Subject: Re: alias addresses vs routing
To: None <>
From: der Mouse <mouse@Rodents.Montreal.QC.CA>
List: tech-net
Date: 02/21/2006 18:33:42
>> # ifconfig ex0
>> # ifconfig ex0 alias

>> Note in particular the lack of a route to 10.100/24 corresponding to
>> the "alias" address.

> if you delete the first address (the /30), the route for /24
> "reappears".  may be a bug in netstat?

That actually makes sense.

I just tried some experiments with all the addresses being aliases, to
avoid issues with the way an alias gets promoted to primary if the
primary address is deleted:

# ifconfig ne2

That address remained primary throughout the experiments.

If I add and then, netstat shows me a
route to the /30.  But if I add them in the other order, it shows me
the route to the /24 and fails to show the route to the /30.

I now suspect both routes are actually present, and the problem is some
kind of confusion in netstat over two routes with "the same
destination" (  Someday if I get the leisure I may dig into
the code and see if I can figure out what's up.

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