How to completely disable IPv6 support on unRaid? I tried this guide but after reboot the sysctl.conf is reset to default.

My network settings tab

Ifconfig result :

root@Tower:/# ifconfig
bond0: flags=5443<UP,BROADCAST,RUNNING,PROMISC,MASTER,MULTICAST>  mtu 9000
        inet6 fe80::76d4:35ff:fe57:10af  prefixlen 64  scopeid 0x20<link>
        ether 74:d4:35:57:10:af  txqueuelen 1000  (Ethernet)
        RX packets 796  bytes 192124 (187.6 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 981  bytes 947091 (924.8 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

br0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 9000
        inet 192.168.2.12  netmask 255.255.255.0  broadcast 192.168.2.255
        inet6 fe80::8c4d:40ff:fe0c:1dff  prefixlen 64  scopeid 0x20<link>
        ether 74:d4:35:57:10:af  txqueuelen 1000  (Ethernet)
        RX packets 792  bytes 177654 (173.4 KiB)
        RX errors 0  dropped 6  overruns 0  frame 0
        TX packets 953  bytes 941117 (919.0 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

eth0: flags=6211<UP,BROADCAST,RUNNING,SLAVE,MULTICAST>  mtu 9000
        ether 74:d4:35:57:10:af  txqueuelen 1000  (Ethernet)
        RX packets 11719  bytes 9582220 (9.1 MiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 9500  bytes 6130516 (5.8 MiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        inet6 ::1  prefixlen 128  scopeid 0x10<host>
        loop  txqueuelen 1000  (Local Loopback)
        RX packets 4  bytes 312 (312.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 4  bytes 312 (312.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

 

The above assignments are just link local addresses and IPv6 is not actively used. Perfectly okay.

 

Sadly its not okay in my case. My router only shows unraid box using ipv6 and not ipv4 which blocks me from port forwarding anything from unraid.

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Edited January 2, 20188 yr by vyreks

I would say that is a badly designed router if it takes IPv6 link local addresses over DHCP assigned IPv4 addresses.

 

I do not recommend to switch-off IPv6 on unRAID and better check your router settings first, but the way to disable IPv6 on unRAID is

sysctl net.ipv6.conf.all.disable_ipv6 = 1
sysctl net.ipv6.conf.default.disable_ipv6 = 1

 

Edited January 2, 20188 yr by bonienl

It is a badly designed router but sadly i cannot change it because it's ISP provided one. IPv6 still comes back after reboot so I will probably have to set up some kind of janky ass forwarding from other device to unraid just to make it work. Thanks for tips.

Have you tried giving your unRAID server a static IPv4 address instead? You'll need to reduce the size of your router's DHCP pool in order to free up one since it currently uses 192.168.2.2 to 192.168.2.254.

I did try it. Router is smarter than static ip though. It catches ipv6 first and shows that instead of ipv4, even though unraid is perfectly reachable via the static ip I set.