Hi there,
While I was looking "how to disable ipv6 under centos" I have found a gazzillion pages about how to do it and some of then even list things that i am not sure where they came from, so for the record I list most of them here in case someone else need them. Some of the methods involved the direct modification of system scripts, and I am against that so I wont list them here (removing the entire section of ipv6 calls in IFUP is not a good idea).
How to disable ipv6 support in Centos 4.x Pick any method, a combo or all of them
Method 1, add the line: alias net-pf-10 off to the /etc/modprobe.conf
Method 2 Add to /etc/sysconfig/network file: NOZEROCONF=yes # Bonus: Disable the ugly generation of 169.254 zeroconf networks. NETWORKING_IPV6=no
Note about method 2. I must mention the fact that I actually READ the entire ifup script and dependencies and I found that it calls at line 361: # if [ "${NETWORKING_IPV6}" = "yes" ]; then # /etc/sysconfig/network-scripts/ifup-ipv6 ${CONFIG}
However adding the NETWORKING_IPV6=NO has no effect whatsoever because even after a reboot the interfaces continue to load an ipv6 address. BTW it does the same for zeroconf and doesn`t work either.
Method 3: /etc/sysconfig/network-scripts/ifcfg-XXXXX file; IPV6INIT=no
So pick your best method or a combo and let us know which one worked for you: In my case Centos 4.3 2.6.9-34.EL i386 with a pair of 3COM 3c905CX lan boards did not responded to Method 1 and 2 and 3. So I'm still battling with this ipv6 thing.
Let me know your comments.
Cheers,