Re: [Cerowrt-devel] [Bloat] ipv6 not quite working for me on internal networks

[Dave Taht <dave.taht@gmail.com>]

On Thu, Jun 16, 2016 at 8:56 PM, Simon Dalley <dalley.simon@gmail.com> wrote:
> Hello,
>
> First, thanks for all the work to make cerowrt what it is.

Was. I am really encouraging everyone to update to lede at this point,
which has nearly everything that was "good" about cerowrt in it.

> I am having some difficulty with ipv6 on the "last hop", namely my internal
> network.
>
> Platform: Netgear WNDR3800
> Cerowrt version: CeroWrt Toronto 3.10.50-1 / LuCI Trunk (svn-r10459)
>
> AQUISS, my UK ISP, provides an ipv6 address range:
>     IPv6 Address 20xx:xxxx:xx55:ae00::/56

Are you getting this via dhcp-pd or is it static?

> Recommended MTU: 1458 bytes
>
> I can make ipv6 work when connecting PC host "centaur" directly to the cable
> modem and running pppd. ping6 ipv6.google.com etc works fine.

The "cable" modem is running over ppp???

>
> Reconnecting via the WNDR3800, everything ipv4 related works fine with
> "centaur" on the se00 subnet.
>
> I can also ping6 without problems from the WNDR3800:
>   root@cerowrt:~# ping6 ipv6.google.com
>   PING ipv6.google.com (2a00:1450:4009:80f::200e): 56 data bytes
>   64 bytes from 2a00:1450:4009:80f::200e: seq=0 ttl=53 time=15.576 ms
>   64 bytes from 2a00:1450:4009:80f::200e: seq=1 ttl=53 time=14.959 ms
>   64 bytes from 2a00:1450:4009:80f::200e: seq=2 ttl=53 time=15.156 ms
>   64 bytes from 2a00:1450:4009:80f::200e: seq=3 ttl=53 time=15.044 ms
>   ^C
>   --- ipv6.google.com ping statistics ---
>   4 packets transmitted, 4 packets received, 0% packet loss
>   round-trip min/avg/max = 14.959/15.183/15.576 ms
>
> but ping6 can't get through from centaur on se00:

A traceroute6 would be better. Try it from various source addresses on
the router.

Disabling the firewall for ipv6 is sometimes helpful also, for debugging.

You might also want a reqprefix of 56 in the wan stanza.

We did not have much chance to test against any other prefix sizes
than 64, 60, and 48.

>   root@centaur:/etc/network# ping6 ipv6.google.com
>   PING ipv6.google.com(lhr25s02-in-x200e.1e100.net) 56 data bytes
>   From lhr25s02-in-x200e.1e100.net icmp_seq=1 Destination unreachable: No
> route
>   From lhr25s02-in-x200e.1e100.net icmp_seq=2 Destination unreachable: No
> route
>   From lhr25s02-in-x200e.1e100.net icmp_seq=3 Destination unreachable: No
> route
>   From lhr25s02-in-x200e.1e100.net icmp_seq=4 Destination unreachable: No
> route
>   ^C
>   --- ipv6.google.com ping statistics ---
>   4 packets transmitted, 0 received, +4 errors, 100% packet loss, time
> 3024ms
>
> For your information, ipv6 routes on centaur are:
>   root@centaur:/etc/network# ip -6 route
>   20xx:xxxx:xx55:ae10::f48 dev eth0  proto kernel  metric 256  expires
> 84847sec pref medium
>   20xx:xxxx:xx55:ae10::/64 dev eth0  proto ra  metric 100  pref medium
>   20xx:xxxx:xx55:ae00::/56 via fe80::2cb0:5dff:fea6:94ad dev eth0  proto ra
> metric 100  pref medium
>   fe80::/64 dev eth0  proto kernel  metric 256  pref medium
>   default via fe80::2cb0:5dff:fea6:94ad dev eth0  proto static  metric 100
> pref medium
>
> and on the router are:
>   root@cerowrt:~# ip -6 route
>   default from :: via fe80::f60f:1bff:fe17:8d00 dev pppoe-ge00  proto static
> metric 1024
>   default from 20:xx:xxxx:xx00:55ae::/64 via fe80::f60f:1bff:fe17:8d00 dev
> pppoe-ge00  proto static  metric 1024

you should also have had a default from

20xx:xxxx:xx55:ae00::/56

I think.

ip -6 route add default from

>   20xx:xxxx:xx55:ae00::/64 dev gw00  proto kernel  metric 256
>   20xx:xxxx:xx55:ae01::/64 dev gw10  proto kernel  metric 256
>   20xx:xxxx:xx55:ae02::/64 dev sw00  proto kernel  metric 256
>   20xx:xxxx:xx55:ae03::/64 dev sw10  proto kernel  metric 256
>   20xx:xxxx:xx55:ae10::/60 dev se00  proto kernel  metric 256

This appears wrong to me in that ae10 should have been a /64

>   unreachable 20xx:xxxx:xx55:ae00::/56 dev lo  proto static  metric
> 2147483647  error -128
>   fe80::/64 dev se00  proto kernel  metric 256
>   fe80::/64 dev ifb0  proto kernel  metric 256
>   fe80::/64 dev sw10  proto kernel  metric 256
>   fe80::/64 dev sw00  proto kernel  metric 256
>   fe80::/64 dev gw10  proto kernel  metric 256
>   fe80::/64 dev gw00  proto kernel  metric 256
>   fe80::/64 dev ge00  proto kernel  metric 256
>   fe80::/10 dev pppoe-ge00  metric 1
>   fe80::/10 dev pppoe-ge00  proto kernel  metric 256
>
> I'm stumped. Can anybody help?
>
> regards, Simon
>
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-- 
Dave Täht
Let's go make home routers and wifi faster! With better software!
http://blog.cerowrt.org