Re: Forcing ISC DHCPd to only bind to one interface?

[Jason Costomiris <jcostom jasons org>]

On Fri, Feb 08, 2002 at 03:02:53PM -0800, David Talkington wrote:
: Find the script that starts dhcpd, and provide as arguments the 
: interfaces you want it to listen to.  It's that easy.

Ah, but it's not that easy at all.

# cat /etc/sysconfig/dhcpd 
# Command line options here
DHCPDARGS=" eth1 "

the process table does indeed show the running process as 
/usr/sbin/dhcpd eth1.

>From /var/log/messages:
Feb  9 00:42:00 elvis dhcpd: Listening on LPF/eth1/00:04:5a:68:61:31/x.y.z.0/24
Feb  9 00:42:00 elvis dhcpd: Sending on   LPF/eth1/00:04:5a:68:61:31/x.y.z.0/24

This certainly suggests that it is only listening on the eth1 interface.
However:

# netstat -an |grep 67
udp        0      0 0.0.0.0:67              0.0.0.0:*

Thus you can see the daemon still binds to all interfaces.

# rpm -q dhcp
dhcp-3.0-6

The same behavior was shown with all other versions of ISC dhcpd tested,
including the standard 2.0pl5 that ships with RH 7.2.

-- 
Jason Costomiris <><           |  Technologist, geek, human.
jcostom {at} jasons {dot} org  |  http://www.jasons.org/ 
          Quidquid latine dictum sit, altum viditur.
                    My account, My opinions.