3. Client Setup

3.1. Downloading the client daemon (dhcpcd)

Depending on your distribution you might have to download the DHCP client daemon. If you want to compile it from the source you package you need is called dhcpcd and the current version is 1.3.18. It is maintained by Sergei Viznyuk <sergei@phystech.com> and today it comes as a binary package with most distributions.

dhcpcd source can be downloaded from following locations

• ftp://ftp.phystech.com/pub/ (Primary site)

• http://www.cps.msu.edu/~dunham/out/

Then follow the instructions below. They should be the same.

3.2. Slackware

You can download the latest copy of the DHCPcd from any Metalab mirror or following:

• ftp://metalab.unc.edu/pub/Linux/system/network/daemons

• ftp://ftp.phystech.com/pub/ (Primary site)

Download the latest version of dhcpcd.tar.gz.

• Unpack it

  tar -zxvf dhcpcd-1.3.18pl1.tar.gz

• cd into the directory and make dhcpcd

  cd dhcpcd-1.3.18pl1

  make

• Install it (you have to run the following command as root)

  make install

This will create the directory /etc/dhcpc where DHCPcd will store the DHCP information and dhcpcd file will be copied into /usr/sbin.

In order to make the system initialize using DHCP during boot type:

cd /etc/rc.d

mv rc.inet1 rc.inet1.OLD

This will move the old network initialization script into rc.inet1.OLD. You now need to create the new rc.inet1 script. Following code is all you need:

#!/bin/sh
#
# rc.inet1      This shell script boots up the base INET system.

HOSTNAME=`cat /etc/HOSTNAME` #This is probably not necessary but I
                             #will leave it in anyways

# Attach the loopback device.
/sbin/ifconfig lo 127.0.0.1
/sbin/route add -net 127.0.0.0 netmask 255.0.0.0 lo

# IF YOU HAVE AN ETHERNET CONNECTION, use these lines below to configure the
# eth0 interface. If you're only using loopback or SLIP, don't include the
# rest of the lines in this file.

/usr/sbin/dhcpcd

Save it and reboot your computer.

When you are finished go the last step.

3.3. RedHat 6.x and Mandrake 6.x

DHCPcd configuration under RedHat 6.0+ is really easy. All you need to do is start the Control Panel by typing control-panel.

• Select "Network Configuration"

• Click on Interfaces

• Click Add

• Select Ethernet

• In the Edit Ethernet/Bus Interface select "Activate interface at boot time" as well as select "DHCP" as "Interface configuration protocol"

Please note that in RedHat 6.x Redhat as default includes a DHCP client called pump instead of above mentioned dhcpcd. CD-ROM does include dhcpcd RPM so if you have no luck with pump try with dhcpcd. After you install dhcpcd (e.g. rpm -i dhcpcd-1.3.17pl2-1.i386.rpm) you will have to make some changes.

Additional notes from Alexander Stevenson <alexander.stevenson@home.com>:

I had no luck with DHCPcd. What finally worked for me was "pump", which comes with Linux Mandrake 6.0 (and so I assume it is included with RedHat as well). The command I used was:

pump -i eth0 -h hostname

It didn't matter what "hostname" was, but without it the server would not respond.

I then changed the line in my /sbin/ifup script to reflect the change; the default version does not have the -h switch, and so didn't work for me.

Basically, if you're using linuxconf, and after setting the adapter to "DHCP" it still doesn't work, try adding a "-h hostname" to the pump line in the /sbin/ifup script. My script now looks like this:

...
if [ -n "$PUMP" ]; then
    echo -n "Determining IP information for $DEVICE..."
    if /sbin/pump -i $DEVICE -h hostname; then
        echo " done."
    else
        echo " failed."
        exit 1
    fi
else ...

Another more elegant way to add hostname field is provided by Aad van der Klaauw:

Currently i'm configuring a gateway system at home, needed to set the MAC address and use the '-h hostname' workaround. So I decided to *not* change the script but to use the configure file. In my /etc/sysconfig/network-scripts/ifcfg-eth0 I have added the following

DEVICE="eth0"
MACADDR="00:11:22:33:44:55"
DHCP_HOSTNAME="trigger_for_terayon"

Which will survive upgrades, and is imho a "cleaner" way.

That is it. Reboot your machine or type /sbin/ifup eth0 on the command line.

3.4. RedHat 5.x

DHCPcd configuration under RedHat 5.0+ is really easy. All you need to do is start the Control Panel by typing control-panel.

• Select "Network Configuration"

• Click on Interfaces

• Click Add

• Select Ethernet

• In the Edit Ethernet/Bus Interface select "Activate interface at boot time" as well as select "DHCP" as "Interface configuration protocol"

When you are finished go the last step.

3.5. RedHat 4.x and Caldera OpenLinux 1.1/1.2

DHCPcd is included in the standard RedHat distribution as an RPM and you can find it on your distribution's CD-ROM in RPMS directory or you can download it from:

ftp://ftp.redhat.com/pub/redhat/redhat-4.2/i386/RedHat/RPMS/dhcpcd-0.6-2.i386.rpm

Install it with rpm -i dhcpcd-0.6-2.i386.rpm.

Alternatively you can compile your own version by following the steps outlined in the Slackware.

The following information was provided to me by nothing <nothing@cc.gatech.edu>.

Removed my static ip and name from /etc/resolv.conf. However, I did leave in the search line and my two nameserver lines (for some reason my dhcpcd never creates a /etc/dhcpc/resolv.conf, so I have to use a static /etc/resolv.conf).

In /etc/sysconfig/network I removed the HOSTNAME and GATEWAY entries. I left the other entries as is (NETWORKING, DOMAINNAME, GATEWAYDEV).

In /etc/sysconfig/network-scripts/ifcfg-eth0 I removed the IPADDR, NETMASK, NETWORK, and BROADCAST entries. I left DEVICE and ONBOOT as is. I changed the BOOTPROTO line to BOOTPROTO=dhcp.

Save the file. Reboot your computer.

When you are finished go the last step.

3.6. Debian

There is a deb package of DHCPcd (make sure it starts with dhcpcd) at:

http://ftp.debian.org/debian/dists/slink/main/binary-i386/net/

Or, follow the Slackware installation instructions.

To unpack the deb package type dpkg -i /where/ever/your/debian/packages/are/dhcpcd*deb.

It appears that there isn't a need for any DHCPcd configuration because:

The contents of the /etc/rc?.d/ dirs is then executed at boot time.

If you don't reboot after installing you should consider starting the daemon manually: /etc/init.d/dhcpcd start.

When you are finished go the last step.

3.7. LinuxPPC and MkLinux

Following section has been written by R. Shapiro

As of the "1999" (R5) release, Linuxppc is now almost completely compatible with Redhat 6, with one caveat (see below). In general the instructions are exactly the same as for the current release of RedHat 6.x and Mandrake 6.x.

The remaining problem is that Redhat 6 uses the 'pump' client for dhcp by default, and 'pump' doesn't work reliably in Linuxppc. To get around this, you should install the latest dhcpcd from Sergei Viznyuk, and then edit /sbin/ifup to use dhcpcd instead of pump.

Change

if [ "$BOOTPROTO" = bootp -o "$BOOTPROTO" = dhcp ]; then
     PUMP=true
 fi

 if [ -n "$PUMP" ]; then

with

 if [  "$BOOTPROTO" = bootp ]; then
       echo " done."
     else
       echo " failed."
       exit 1
     fi
 elif [ "$BOOTPROTO" = dhcp ]; then
     echo -n "Determining IP information for $DEVICE..."
     if /sbin/dhcpcd -d $DEVICE ; then
       if [ -f /etc/dhcpc/dhcpcd-${DEVICE}.exe ]; then
           /etc/dhcpc/dhcpcd-${DEVICE}.exe
       fi

and a coresponding changes for ifdown. Change

if [ "$BOOTPROTO" = bootp -o "$BOOTPROTO" = dhcp ]; then
....
fi

with

if [ "$BOOTPROTO" = bootp ]; then
fi

if [ "$BOOTPROTO" = dhcp ]; then
      if [ -f /var/run/dhcpcd-${DEVICE}.pid ]; then
              kill `cat /var/run/dhcpcd-${DEVICE}.pid`
              rm -f /var/run/dhcpcd-${DEVICE}.pid
      fi
fi

A working ppc rpm for dhcpcd is included on the Linuxppc 1999 cd; a slightly later rpm is available in the contrib directory on ftp://ftp.linuxppc.org/. Sources, which compile out of the box in Linuxppc 1999, are available from ftp://ftp.phystech.com/pub/dhcpcd-1.3.17-pl9.tar.gz.

3.8. Tying it all together

After your machine reboots your network interface should be configured. Type: ifconfig.

You should get something like this:

          lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Bcast:127.255.255.255  Mask:255.0.0.0
          UP BROADCAST LOOPBACK RUNNING  MTU:3584  Metric:1
          RX packets:302 errors:0 dropped:0 overruns:0 frame:0
          TX packets:302 errors:0 dropped:0 overruns:0 carrier:0 coll:0

eth0      Link encap:Ethernet  HWaddr 00:20:AF:EE:05:45
          inet addr:24.128.53.102  Bcast:24.128.53.255  Mask:255.255.254.0
          ^^^^^^^^^^^^^^^^^^^^^^^
          UP BROADCAST NOTRAILERS RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:24783 errors:1 dropped:1 overruns:0 frame:1
          TX packets:11598 errors:0 dropped:0 overruns:0 carrier:0 coll:96
          Interrupt:10 Base address:0x300 

If you have some normal number under inet addr you are set. If you see 0.0.0.0 don't despair, it is a temporary setting before dhcpcd acquires the IP address. If even after few minutes you are seeing 0.0.0.0 please check out Troubleshooting. DHCPcd is a daemon and will stay running as long as you have your machine on. Every three hours it will contact the DHCP server and try to renew the IP address lease. It will log all the messages in the syslog (on Slackware /var/adm/syslog, RedHat/OpenLinux /var/log/syslog).

One final thing. You need to specify your nameservers. There are two ways to do it, you can either ask your provider to provide you with the addresses of your name server and then put those in the /etc/resolv.conf or DHCPcd will obtain the list from the DHCP server and will build a resolv.conf in /etc/dhcpc.

I decided to use DHCPcd's resolv.conf by doing the following:

Back up your old /etc/resolv.conf: mv /etc/resolv.conf /etc/resolv.conf.OLD

If directory /etc/dhcpc doesn't exist create it: mkdir /etc/dhcpc

Make a link from /etc/dhcpc/resolv.conf to /etc/resolv.conf: ln -s /etc/dhcpc/resolv.conf /etc/resolv.conf

If that doesn't work try this (fix suggested by <nothing@cc.gatech.edu> with a little amendment by Henrik Stoerner):

This last step I had to perform only because my dhcpcd doesn't create an /etc/dhcpc/resolv.conf. In /etc/sysconfig/network-scripts/ifup I made the following changes (which are a very poor hack, but they work for me):

elif [ "$BOOTPROTO" = dhcp -a "$ISALIAS" = no ]; then
    echo -n "Using DHCP for ${DEVICE}... "
    /sbin/dhcpcd -c /etc/sysconfig/network-scripts/ifdhcpc-done ${DEVICE}
    echo "echo \$$ > /var/run/dhcp-wait-${DEVICE}.pid; exec sleep 30" | sh

    if [ -f /var/run/dhcp-wait-${DEVICE}.pid ]; then
	^^^^
        echo "failed."
        exit 1

I changed to:

elif [ "$BOOTPROTO" = dhcp -a "$ISALIAS" = no ]; then
    echo -n "Using DHCP for ${DEVICE}... "
    /sbin/dhcpcd
    echo "echo \$$ > /var/run/dhcp-wait-${DEVICE}.pid; exec sleep 30" | sh

    if [ ! -f /var/run/dhcp-wait-${DEVICE}.pid ]; then
	^^^^^^
       echo "failed."
       exit 1

Now sit back and enjoy :-).

3.9. Various notes

Following step(s) are not necessary but might be useful to some people:

1. If you need network connectivity only occasionally you can start dhcpcd from the command line (you have to be root to do this) with: /usr/sbin/dhcpcd.

   When you need to down (turn off) the network type /usr/sbin/dhcpcd -k.

3.10. Troubleshooting

If you have followed the steps outlined above and you are unable to access the network there are several possible explanations:

eth0: 3c509 at 0x300 tag 1, 10baseT port, address  00 20 af ee 11 11, IRQ 10.
3c509.c:1.07 6/15/95 becker@cesdis.gsfc.nasa.gov

        IFNAME=$[ {DEVICE} \
        "/sbin/dhcpcd -r -c /etc/"- etc etc.    

eth0: 3c509 at 0x300 tag 1, 10baseT port, address  00 20 af ee 11 11, IRQ 10.
		            ^^^^^^^^^^^^
3c509.c:1.07 6/15/95 becker@cesdis.gsfc.nasa.gov

DHCP received an unknown option 067 of length 005. The raw option data is 
given  below.

0000: 62 61 73 69 63            basic

3.11. Alternative DHCP client (ISC dhclient)

If you have not had success getting your Linux connection running with the dhcpcd you might want to try ISC dhclient. dhclient comes with the DHCP distribution from ISC which includes both a DHCP client and a DHCP server. Instructions on how to get and compile the DHCP distribution can be found here. When you are done with it please return to this section to configure the client.

With the current version of the DHCP client, you don't actually need a dhclient.conf. All you have to do is invoke dhclient e.g.: /sbin/dhclient.

This will configure all broadcast interfaces. If this doesn't work or you want to specify only one interface create a /etc/dhclient.conf file with this example configuration.

interface "eth0" {
  send dhcp-client-identifier 1:xx:xx:xx:xx:xx:xx;
  send dhcp-lease-time 86400;
}

Here we assume that the ethernet interface is eth0. If not change accordingly. Also replace xx:xx:xx:xx:xx with your ethernet address. This dhclient.conf makes the client look more like a Win95 client.