Both RHEL 7 and 8 are IPv6 capable. These instructions are for RHEL 7, but they should be identical for RHEL 8.
Network Setup
- Enable IPv6 and assign the address in /etc/sysconfig/network-scripts/ifcfg-xxx, along with the IPv6 router.
IPV6INIT=yes IPV6_AUTOCONF=no IPV6_DEFROUTE=yes IPV6_FAILURE_FATAL=no IPV6_DEFAULTGW=2001:49c8:4000:120C::1 IPV6ADDR=2001:49c8:4000:120C::2221/64
- Restart the network service.
service network restart - Add AAAA records to DNS for your host.
- Firewall: In RHEL the IPv6 firewall is a completely different service from the IPv4 firewall, with its own configuration file. All the TCP/UDP ports that are opened for IPv4 must also be specified in a separate configuration file for IPv6. You may or may not have a default /etc/sysconfig/ip6tables file. To generate a default one, use the ip6tables “save” command.
Troubleshooting and Gotchas
Several of the basic network utilities have explicit IPv6 operations.
- ping has two separate binaries: “ping” and” ping6″. To test internet
connectivity, run “ping ipv6.google.com”. - nmap has a “-6” flag that makes it work over IPv6.
- The older “route” command doesn’t support IPv6. This command has been
deprecated for a while in favor of “ip route”. You can use
“ip – 6 route” to view the IPv6 route tables. - “nslookup” defaults to only looking up A records, whereas the “host”
command will return both A and AAAA.
If you are going to load an IPv6 numeric address in Firefox, you must wrap the
IP in brackets. “http://fd00:77/” does’t work in Firefox’s URL address bar,
but “http://[fd00:77]/” does.