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

Simon Dalley dalley.simon at gmail.com
Tue Jun 21 17:20:46 EDT 2016 

On 17/06/16 15:21, Dave Taht wrote:
> On Thu, Jun 16, 2016 at 8:56 PM, Simon Dalley<dalley.simon at 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.
Well, the nice thing about cerowrt "was" its improved list of setup 
defaults vs. openwrt, not least the routed-instead-of-bridged subnets 
which is so helpful on mixed wired/wireless. Has this been carried over 
into lede? Is there a recommended cerowrt-flavoured git branch in lede?
>> 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?
I had set the Network | Interfaces | GE00 check box "Enable IPv6 
negotiation on the PPP link" and the options below for the WAN6 
interface, but that didn't seem to do anything. Only when I added an 
explicit value for the "ipv6prefix" option did any global ipv6 addresses 
appear. In /etc/config/networks:
config interface 'wan6'
     option ifname '@ge00'
     option proto 'dhcpv6'
     option broadcast '1'
     option metric '2048'
     option reqprefix '56'
     option reqaddress 'try'
     option ip6prefix '20xx:xxxx:xx55:ae00::/56'

config interface 'ge00'
     option _orig_ifname 'ge00'
     option _orig_bridge 'false'
     option ifname 'ge00'
     option proto 'pppoe'
     option ipv6 '1'
     option username 'xxxxx at aquiss.com'
     option password 'xxxxx'
     option mtu '1458'


>> 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???
Sorry, I shouldn't have just glibly said "cable modem". It's actually a 
FTTC DSL modem, serving via PPPoE. When I was trying it directly from 
the PC, I set it up using pppoeconf under ubuntu.
>> 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 at 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.
 From centaur on se00:
root at centaur:/etc/network# traceroute6 ipv6.google.com
traceroute to ipv6.l.google.com (2a00:1450:400b:c00::71) from 
20xx:xxxx:xx55:ae02::f48, 30 hops max, 24 byte packets
  1  20xx:xxxx:xx55:ae02::1 (20xx:xxxx:xx55:ae02::1)  0.498 ms !N 0.559 
ms !N  0.438 ms !N

 From cerowrt using default interface:
root at cerowrt:/etc/config# traceroute6 ipv6.google.com
traceroute to ipv6.google.com (2a00:1450:4009:80e::200e), 30 hops max, 
16 byte packets
  1  fe80::f60f:1bff:fe17:8d00%pppoe-ge00 
(fe80::f60f:1bff:fe17:8d00%pppoe-ge00)  8.742 ms  8.763 ms  8.595 ms
  2  gi1-2.inx.dist.dsl.enta.net (2001:4d48:feed:58::a)  8.901 ms 8.512 
ms  8.410 ms
  3  te2-2.interxion.dsl.enta.net (2001:4d48:feed:4b::a)  8.825 ms 8.628 
ms  8.749 ms
  4  te2-3.interxion.core.enta.net (2001:4d48:feed:22::a)  9.024 ms 
7.482 ms  9.070 ms
  5  2001:4d48:ace::44 (2001:4d48:ace::44)  15.690 ms  17.611 ms 15.333 ms
  6  2001:4d48:ace::43 (2001:4d48:ace::43)  15.427 ms  15.566 ms 16.255 ms
  7  2001:4860:1:1:0:2114:0:5 (2001:4860:1:1:0:2114:0:5)  15.109 ms 
14.715 ms  14.300 ms
  8  2001:4860:1:1:0:2114:0:4 (2001:4860:1:1:0:2114:0:4)  14.467 ms 
15.516 ms  14.986 ms
  9  2001:4860::1:0:cd12 (2001:4860::1:0:cd12)  15.367 ms  15.571 ms 
15.638 ms
10  2001:4860::8:0:87b7 (2001:4860::8:0:87b7)  14.824 ms  24.848 ms 
15.119 ms
11  2001:4860::8:0:ac54 (2001:4860::8:0:ac54)  15.387 ms  29.964 ms 
15.637 ms
12  2001:4860::1:0:ab9d (2001:4860::1:0:ab9d)  16.347 ms  16.363 ms 
15.685 ms
13  2001:4860:0:1::1b27 (2001:4860:0:1::1b27)  16.147 ms  16.556 ms 
15.459 ms
14  2001:4860:0:1::1755 (2001:4860:0:1::1755)  15.657 ms  15.828 ms 
15.434 ms
15  lhr25s01-in-x200e.1e100.net (2a00:1450:4009:80e::200e)  15.515 ms  
15.551 ms  15.457 ms

 From cerowrt but using se00 interface's address:
root at cerowrt:/etc/config# traceroute6 -s 20xx:xxxx:xx55:ae02::1 
ipv6.google.com
traceroute to ipv6.google.com (2a00:1450:4009:80e::200e) from 
20xx:xxxx:xx55:ae02::1, 30 hops max, 16 byte packets
  1traceroute6: sendto: Operation not permitted


> Disabling the firewall for ipv6 is sometimes helpful also, for debugging.
I tried
     /etc/init.d/firewall stop

but that disabled all traffic. What's the recommended way of temporarily 
enabling everything?
> You might also want a reqprefix of 56 in the wan stanza.
Already done.
> We did not have much chance to test against any other prefix sizes
> than 64, 60, and 48.
>
>>    root at 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 at 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 at 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
I changed the "config interface 'se00'" option ip6assign back from '60' 
to '64'. Did not affect the routing problem. (I had earlier changed it 
to '60' to see if it made any difference.)
>>    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
>>
>> _______________________________________________
>> Bloat mailing list
>> Bloat at lists.bufferbloat.net
>> https://lists.bufferbloat.net/listinfo/bloat
>>
>

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