I see that "netstat -ib" shows the same bytes for an alias as the link
itself:

1.5.1_BETA/i386:
ne0   1500  <Link>        00:50:45:6e:34:2a  790994855  171464759
ne0   1500  fe80::        fe80::240:5ff:fe6  790994855  171464759
ne0   1500  192.168       rainier            790994855  171464759
ne0   1500  192.168.0.207 192.168.0.207      790994855  171464759

1.4.2/i386:
fxp0  1500  <Link>        00:b0:c7:08:99:8c 3617679533  196657410
fxp0  1500  10.2/16       10.2.1.236        3617679533  196657410
fxp0  1500  10            10.2.3.26         3617679533  196657410

It seems like I read about this before, but a search at gnats and the
mailing list archives didn't find anything.

How can I easily find traffic per each alias?

Or should I use some IP Filter rule to count the traffic for each alias?

(I read that with Linux kernel 2.2 that this feature of counting alias
traffic was removed, because it was often wrong.)

In addition, is there some easy way to find out traffic routed through a
NetBSD system (by destination IP)?

I am curious about this, because I wrote a simple tool to analyze traffic
-- and I want to be able to also analyze traffic to network address
aliases and traffic going through the gateway (by IP). 9I guess i should
have a closer look at where mrtg or snmp gets this info.) Here is an
example report:  
http://www.reedmedia.net/software/analyze_interface_bytes/example-20011010.txt
(I plan on changing the name.)

Thanks,

   Jeremy C. Reed
   http://www.reedmedia.net/