Summary: Solaris 2.6 interface groups

From: Mark Trotter (
Date: Thu Nov 13 1997 - 14:11:58 CST

Well it looks like I had it correct in my orignal post but I did not know
that after you set /dev/ip ip_enable_group_ifs to 0 the last interface
defined is the one used. One thing that was not clear was if last
interface was leo:254 or if it meant last defined, after some testing it
appears that what is meant is last defined.

 I setup the following script to setup the aliases:
I want this machine to be FROM XXX.XXX.XXX.10
Machine boots up as XXX.XXX.XXX.11 in /etc/hosts(or depending on how you
setup your box /etc/hostname.le0). Once a patch for this is made I just
have to swap .11 and .10 and I am where I want to be.
ndd -set /dev/ip ip_enable_group_ifs 0

/sbin/ifconfig le0:2 XXX.XXX.XXX.12 up

/sbin/ifconfig le0:3 XXX.XXX.XXX.13 up

/sbin/ifconfig le0:1 XXX.XXX.XXX.10 up

As a side note: I need an external CDROM and a tape backup (8mm) for a
sparc 5. I am trying to keep costs down and I know about the SUN/PC/CDROM
FAQ but I have not found any good information on tape drives is there such
a faq? Also where besides sun express do people get sun/generic sun


Date: Tue, 4 Nov 1997 14:31:27 -0800 (PST)
From: Mark Trotter <>
Subject: Solaris 2.6 interface groups

I have just setup a machine with Solaris 2.6. The machine has a few
virtual hosts on it. Whenever I make a connection from the machine
(telnet) the machine "randomly" picks one of the virtual interfaces and
says I am from "". I have tracked it down
to this in the ifconfig man page:
     If an interface (logical or physical) shares an IP prefix
     with another interface, these interfaces are collected into
     an interface group. IP uses an interface group to rotate
     source address selection when the source address is unspeci-
     fied, and in the case of multiple physical interfaces in the
     same group, to scatter traffic across different IP addresses
     on a per-IP-destination basis. (See netstat(1M) for per-
     IP-destination information.)

     This feature may be disabled by using ndd(1M).

The problem is that I can not figure out what needs to be changed.

I believe it might be /dev/ip ip_enable_group_ifs but setting that to 0
did not seem to change the behavior.

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