Changing dhcpcd to dhclient in startup scripts

S.Pole · 01-13-2011, 01:08 PM

I recently upgraded to a Intel i3 cpu and Intel H55 motherboard. This was from an old P4 machine that was running Slackware 13.0. The machine is a single connection to the internet through a cable modem.

I moved the hard drives over, and found that dhcpcd would not work with this board in either Slackware 13.0 or 13.1 (after updating). I tried both the Gigabit onboard Lan, an old PCI ethernet card, and installing the most recent version of dhcpcd. No luck.

Dhcpcd would negotiate the lease with my cable modem, assign an IP address. But after that the process stalled. The internet was unreachable, and no nameservers were printed in /etc/resolv.conf. Manually killing dhcpcd and entering: "dhclient -4 eth0" got me on the internet without a problem.

As this appears to be a lingering problem with dhcpcd, I am going to try to use dhclient permanently.

Has anyone else moved over to using dhclient? If you have modified your startup scripts in /etc/rc.d to use dhclient, could you please post them so I could see what approach you have taken?

piratesmack · 01-13-2011, 02:38 PM

I think the easiest way would be to install the Wicd network manager from the extra folder on your Slackware media. Make sure to read /usr/doc/wicd-1.7.0/README.SLACKWARE after installing.

You can change the DHCP client in Wicd's preferences.

rg3 · 01-13-2011, 04:15 PM

Code:

mv -i /etc/rc.d/rc.inet1 /etc/rc.d/rc.inet1.bak
cat >/etc/rc.d/rc.inet1 <<EOF
#!/bin/sh
/sbin/ifconfig lo 127.0.0.1
/sbin/route add -net 127.0.0.0 netmask 255.0.0.0 lo
/sbin/dhclient -4 eth0
EOF
chmod 755 /etc/rc.d/rc.inet1

S.Pole · 01-13-2011, 07:00 PM

Quote:

Originally Posted by rg3

Code:

mv -i /etc/rc.d/rc.inet1 /etc/rc.d/rc.inet1.bak
cat >/etc/rc.d/rc.inet1 <<EOF
#!/bin/sh
/sbin/ifconfig lo 127.0.0.1
/sbin/route add -net 127.0.0.0 netmask 255.0.0.0 lo
/sbin/dhclient -4 eth0
EOF
chmod 755 /etc/rc.d/rc.inet1

Many thanks. This worked like a charm. Thanks also for the link to Wicd. I'm going to install this from /extra and play around with it tonight.

What is the status of the dhcpcd project? Is it still the main dhcp, or is it losing ground to dhclient?

Theta13579 · 12-08-2011, 06:36 AM

rg3 · 12-09-2011, 11:22 AM

Now that you revived the thread it's worth pointing out my quick&dirty hack has a small problem. When the script is called with the "stop" argument it's supposed to bring the network down and it doesn't because it only tries to bring it up. Nowadays I use a script like this:

Code:

#!/bin/sh
start()
{
        # lo
        /sbin/ip addr add 127.0.0.1/8 dev lo
        /sbin/ip link set lo up
        /sbin/ip route add 127.0.0.0/8 dev lo

        # eth0
        /sbin/dhcpcd eth0
}

stop()
{
        # eth0
        /sbin/dhcpcd -k eth0

        # lo
        /sbin/ip route del 127.0.0.0/8
        /sbin/ip link set lo down
        /sbin/ip addr del 127.0.0.1/8 dev lo
}

case "$1" in
        stop|down)
                stop
                ;;
        restart)
                stop
                start
                ;;
        *)
                start
                ;;
esac

Of course, the call to dhcpcd can be replaced with dhclient -4 or whatever.

GazL · 12-09-2011, 11:50 AM

When you see something as simple as this you have to wonder why rc.inet1 and rc.wireless and the like have to be quite so long and complicated (and even they are simple compared to some of the other distro's sysconfig scripts). When the scripts used to 'make things easy' become more complicated than the few simple commands they are replacing then I think it's time to take a look at them.

One of the things I liked about OpenBSD is its simplistic approach to configuring network interfaces via its use of /etc/hosname.$interface. I think you've just prompted me to have a go at something similar.. Thanks for posting.