Using DHCPv6 with SLC5

Submitted by emartell on Wed, 12/11/2013 - 09:23

Problem description: using DHCPv6 on SLC5 at CERN requires some tweaking of the network configuration files, due to a RedHat bug ( and the way devices are authorized to connect to the network at CERN (i.e. by MAC address identification). There's also a problem with the default dhcpv6 client which uses a DUID not compatible with the CERN's need.

Solution: Follow these steps:

1) ip6tables drops the dhcpv6 lease packets from the DHCPv6 servers. In /etc/sysconfig/ip6table add this line (before the REJECTs):

-A RH-Firewall-1-INPUT -m state --state NEW -m udp -p udp --dport 546 --sport 547 -s fe80::/10 -d fe80::/10 -j ACCEPT

2) The default DUID is not good for CERN. The DUID  is in the file /var/lib/dhcpv6/dhcp6c_duid and can be created with this perl script. Execute these commands as root:

cd /var/lib/dhcpv6
rm client6.leases*
chmod 700
./ -t now -m 00:15:5D:FF:4B:37
(use the MAC addres of the eth interface registered in landb)

3) Enable the dhcpv6 client at boot time

To the file  /etc/sysconfig/network-scripts/ifcfg-eth0 add the line

Be sure to remove the line IPV6INIT=yes in case it's there

4) Enable IPv6 networking

To the file  /etc/sysconfig/network add these lines

5) Restart ip6table and the network service, or reboot the server








Operating System