IP routing subnet mask bug?

[Steve Dyer]

In article <397 at itcatl.UUCP> robin at itcatl.UUCP (Robin Cutshaw) writes:
>Guess I should have included more detail.  I am using ifconfig with
>netmask 255.0.0.0 and broadcast MYNET.255.255.255.  ifconfig shows
>the netmask to be ff000000 but it actually arp's 000000ff...

Uh, I don't know what you mean by "arp"ing 000000ff, but...  I'd ask:

What's your (Class A) net number for MYNET?  Strictly speaking, most systems
derived from the 4.x network code don't require you to specify a netmask if
your network convention is the same as the "natural" netmask for your network
number.

Urgh--that's awkwardly phrased.
Class A networks (001-127.h.h.h) have a "natural" netmask of 255.0.0.0.
Class B networks (128-191.n.h.h) have a "natural" netmask of 255.255.0.0, and
class C networks (192-223.n.n.h) have a "natural" netmask of 255.255.255.0.

I'm running with a class A net address (net 18) with a netmask of 255.255.0.0
(16 bits of host) with AIX PS/2, and it works flawlessly.  I suspect you're
neglecting to mention some bit of information here.

-- 
Steve Dyer
dyer at ursa-major.spdcc.com aka {ima,harvard,rayssd,linus,m2c}!spdcc!dyer
dyer at arktouros.mit.edu, dyer at hstbme.mit.edu