eth4      Link encap:Ethernet  HWaddr 74:d4:35:e3:60:35
          inet addr:10.10.10.1  Bcast:10.10.10.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:11 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:0 (0.0 B)  TX bytes:2569 (2.5 KiB)
          Interrupt:105 Base address:0x8000

empire@linuxcnc:~$ sudo /sbin/sysctl -a | grep disable_ipv6
[sudo] password for empire:
net.ipv6.conf.all.disable_ipv6 = 0
net.ipv6.conf.default.disable_ipv6 = 0
net.ipv6.conf.lo.disable_ipv6 = 0
net.ipv6.conf.eth4.disable_ipv6 = 1
net.ipv6.conf.eth3.disable_ipv6 = 0
empire@linuxcnc:~$