I am having problems getting IPv6 working on my network. It started when trying to get IPv6 to my Xbox One. I am getting IPv6 from my isp, who is Comcast. I have prefix on WAN6 but not on LAN.
This is my network config:
Reading comcast forums a bit about getting more than a /64 it appears that comcast can do this, but that you tend to get bound in with whatever your router originally requested, so you might need to get a comcast tech support person to "release" your subnet so you can request a /56 or a /60.
On your router in LuCI go to the interfaces tab, select the WAN6 interface, and make sure it is requesting a prefix of length 56. Then save and graceful reboot your router. If you still don't get a prefix, try dropping it to a length 60. If you still don't get a prefix, try putting it back to 56, save, and then call comcast and tell them you have multiple networks in your house and you need your ipv6 prefix to be larger than a /64, ask them to release your prefix so you can request a larger one. Ask them what size prefixes they hand out. Then once they've done that, try a reboot to get the /56 prefix. If that doesn't work, drop it to a /60. Any ISP that insists on giving out less than a /60 is broken. And comcast is not broken with respect to ipv6 they actually spearheaded the rollout.
this is on your router? (I'm guessing not, probably a desktop or laptop running linux on your lan?) I only see one ethernet eno1 and no VLAN devices. Are you routing from ethernet to wireless with zero wired LAN network?
Also I see no public prefixes at all, but I do see two different ULAs:
fd35:bad9:9ce5:0:: and fdbf:b03b:dab:0::
maybe one of your APs is also advertising a ULA? You should probably advertise just ONE ULA on your LAN.
I used putty to connect to the router with a mint linux computer that is hard wired to the switch. Do I need to be connected directly to router without switch?
eno1 has only a 192.168.1.232/24 ipv4 and a bunch of ULAs, this device has zero public IPs, how can it be your router? Perhaps you accidentally ran the "ip addr show" on the linux mint machine? ssh into the router again and run it on the router.
Edit: putty is a windows program, you probably want "ssh"
root@tubescreamer:~# ping6 -c 10 google.com
PING google.com (2607:f8b0:4004:801::200e): 56 data bytes
64 bytes from 2607:f8b0:4004:801::200e: seq=0 ttl=55 time=15.855 ms
64 bytes from 2607:f8b0:4004:801::200e: seq=1 ttl=55 time=11.894 ms
64 bytes from 2607:f8b0:4004:801::200e: seq=2 ttl=55 time=10.926 ms
64 bytes from 2607:f8b0:4004:801::200e: seq=3 ttl=55 time=11.330 ms
64 bytes from 2607:f8b0:4004:801::200e: seq=4 ttl=55 time=11.795 ms
64 bytes from 2607:f8b0:4004:801::200e: seq=5 ttl=55 time=11.157 ms
64 bytes from 2607:f8b0:4004:801::200e: seq=6 ttl=55 time=11.538 ms
64 bytes from 2607:f8b0:4004:801::200e: seq=7 ttl=55 time=11.039 ms
64 bytes from 2607:f8b0:4004:801::200e: seq=8 ttl=55 time=11.982 ms
64 bytes from 2607:f8b0:4004:801::200e: seq=9 ttl=55 time=12.086 ms
--- google.com ping statistics ---
10 packets transmitted, 10 packets received, 0% packet loss
round-trip min/avg/max = 10.926/11.960/15.855 ms
I've been reading about IPv6 and moved my router to OpenWRT so I can properly use IPv6, but I haven't yet found explanation on why we need a prefix bigger than /64.
Could somebody explain it or point to an article that do so? Why can't we create multiple networks with subnets shorter than /64, say it /70?
A /64 is the smallest possible subnet allowing SLAAC to work. While smaller subnets would be possible with DHCPv6 or manual assignment, they are not really viable and you'd be in a world of pain trying to use them.
SLAAC requires /64 since the host generates its own 64 bit interface identifiers. This identifier used to be an EUI-64 containing a MAC-48. But this is not recommended nowadays. Instead you use an temporary or permanent opaque bit string.
With dhcpv6 you can use other prefixes. But some devices such as android don't support dhcpv6 which means SLAAC is recommended for LANs.