Strange ifconfig/ip-alias behavior

Strange ifconfig/ip-alias behavior

Post by dscordi » Thu, 17 Feb 2000 04:00:00

Wondering if anyone else has noticed this:

I'm running kernel 2.2.14 and the netbase that came with Debian 2.1 (I
think it's 1.3.4).  IP-Aliasing seems to work as described in the Howto,
but I've noticed something curious:  ifconfig doesn't list the aliased
interface.  I have eth0 set to no IP (set dynamically by pppoe), and
eth0:0 set to an internal IP address (192.168.x.x).  Route shows that
the net is handled by eth0 (which has no ip), when I think
it should be handled by eth0.0.

Any ideas?  I think ifconfig is a part of netbase, should I update
that?  And if so...where is it?

Thanks in advance,


Strange ifconfig/ip-alias behavior

Post by Malwar » Thu, 17 Feb 2000 04:00:00

Hi Shawn,

> but I've noticed something curious:  ifconfig doesn't list the aliased
> interface.  I have eth0 set to no IP (set dynamically by pppoe), and

This should be only a problem with out of date versions of the
net-tools. However the net-tools package is no longer the first choice.
While it is simple it can not handle all new features. With aliases even
later releases will shutdown all aliases and the base interface (eth0)
with "ifconfig down eth0:0". The package ip-route is the one to be used
while net-tools should stay installed in order not have to rewrite all
network related init scripts.



1. ipip tunneling in 2.1.x: strange ifconfig/pointopoint behavior

Can anyone offer me help in setting up an ipip tunnel under
a recent version of 2.1.x?

It seems the behavior of ifconfig has changed in 2.1.x.  I
can't seem to get ifconfig to set IFF_POINTOPOINT.  This
works for me in kernel 2.1.65, but I've tried several later
versions and none of them will allow me to do the following:

# ifconfig tunl0 netmask \

In 2.1.105, for example, this yields the following:

tunl0     Link encap:IPIP Tunnel  HWaddr  
          inet addr:  Mask:
          UP RUNNING NOARP  MTU:1480  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0

Furthermore, a "magic" route is added:   *   U     0      0        0 tunl0

This route is not at all what I need. should be
routed through tunl0, not  I haven't been able
to determine how to get ifconfig to not create "magic" routes
for me when i configure a device.

So, why am I messing with 2.1.x anyway?  Why can't I just use 2.0?
I need this to work in version at least 2.1.70 or greater, as the new
2.1.x smbfs support (added in 2.1.70) works with Pathworks 5, whereas
the older 2.0.x smbfs does not.

I've combed the docs, the kernel source, dejanews, altavista, you
name it, for about two weeks and have not turned up anything, so I
would be eternally grateful if someone could point me in the right

      Ben Armstrong                -.       Medianet Development Group,

      <URL:>    `-  Halifax, Nova Scotia, Canada

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