cancel
Showing results for 
Search instead for 
Did you mean: 
yarrum
Aspiring Contributor
367 Views
Message 1 of 10

Hub 6 and IPv6 loss on re-sync

I have a Hub 6A on firmware SG4B10002244.

If I power-cycle the unit, I get IPv6 enabled from the network. Some days later, a re-sync happens, and IPv6 becomes disabled. The only way to get IPv6 back is to power-cycle again (or do a reboot).

This is consistent and repeatable.

I can see from the Event Log that it appears to be a DHCPv6 problem.

 

I have read elsewhere on this forum that others are having similar issues, and some say the HH6 has a bug, other say the network IPv6 has glitches. Those posts all seem to be weeks/months old.

 

I'd like to check what the current status of this is - whether I should just be patient and wait for a known problem to be fixed, or whether this needs further attention (e.g. settings change) ?

 

0 Ratings
Reply
9 REPLIES 9
Distinguished Sage
365 Views
Message 2 of 10

Re: Hub 6 and IPv6 loss on re-sync

just be patient
0 Ratings
Reply
yarrum
Aspiring Contributor
350 Views
Message 3 of 10

Re: Hub 6 and IPv6 loss on re-sync

Thanks john46,

So, by that reply, I am to infer that my problem symptoms are recognised, known, and a fix is in hand? I realise this is a community forum, but has there been any official acknowledgement of the nature of the issue, scope, and possible date of resolution ?

 

0 Ratings
Reply
Checked2013
Expert
341 Views
Message 4 of 10

Re: Hub 6 and IPv6 loss on re-sync

I do find that the Hub 6 does take a lot longer to boot up. Once booted and connected to the internet I have found that it takes a min or two for it to get IPv6.

 

You may want to look into why you are getting re-syncs?

0 Ratings
Reply
yarrum
Aspiring Contributor
335 Views
Message 5 of 10

Re: Hub 6 and IPv6 loss on re-sync

Checked2013,

I know exactly why I am getting re-syncs, but that is not the question here. I can force a re-sync (disconnect/connect) on demand, and 100% of the time, I lose IPv6.

The only way to get v6 back is to reboot. It is so consistent and predictable that I'm sure it is a bug somewhere.

Obviously I don't want to cause reboots frequently, because it damages the DLM rating (I'm already hurting from this), but I need IPv6 for development uses.

So, on one hand, BT are saying their v6 rollout is complete, so I get onboard. The only problem is that it's flaky, and that's not good. So, I'm looking for an official line from BT about this issue.

 

0 Ratings
Reply
Distinguished Sage
328 Views
Message 6 of 10

Re: Hub 6 and IPv6 loss on re-sync


@yarrum wrote:

Thanks john46,

So, by that reply, I am to infer that my problem symptoms are recognised, known, and a fix is in hand? I realise this is a community forum, but has there been any official acknowledgement of the nature of the issue, scope, and possible date of resolution ?

 


no information known at this time

0 Ratings
Reply
Checked2013
Expert
323 Views
Message 7 of 10

Re: Hub 6 and IPv6 loss on re-sync

The only answer that is logical is either to wait until BT gets around to fixing this issue or fix the issue you have with the re-syncs so that you don't have a problem by having to reboot all the time because of the re-syncs

0 Ratings
Reply
smf22
Recognised Expert
294 Views
Message 8 of 10

Re: Hub 6 and IPv6 loss on re-sync


@yarrum wrote:

The only way to get v6 back is to reboot. It is so consistent and predictable that I'm sure it is a bug somewhere.

Obviously I don't want to cause reboots frequently, because it damages the DLM rating (I'm already hurting from this), but I need IPv6 for development uses.

So, on one hand, BT are saying their v6 rollout is complete, so I get onboard. The only problem is that it's flaky, and that's not good. So, I'm looking for an official line from BT about this issue.

 


A problem with IPv6 on the Hub 6 was acknowledged by @DanielS in March 2016 in message 43 of the post How do I re-enable IPv6 on my HH6?. That post doesn't mention the firmware level being used specifically, but the version SG4B10002244 you're using has been the latest since Nov/Dec 2016 so I would assume the OP of that post was using the same version as you.

 

As you say the Hub has IPv6 operating OK if you perform a reboot it's possible that the problem is related to the Hub renewing the IPv6 'lease' on the WAN for the delegated prefix. The IPv6 address prefix is requested by the Hub using DHCPv6 and the client will renew that lease after a certain period. From a packet capture from when my router connects it would seem with BT that period is 7 days (604800 seconds) as seen by the T1 value in the capture.

 

DHCPv6
    Message type: Reply (7)
    [snip]
    Identity Association for Prefix Delegation
        Option: Identity Association for Prefix Delegation (25)
        Length: 41
        Value: 0000000000093a8000127500001a001912cc030012cc0300...
        IAID: 00000000
        T1: 604800
        T2: 1209600
        IA Prefix
            Option: IA Prefix (26)
            Length: 25
            Value: 12cc030012cc0300382a0023c55501bd0000000000000000...
            Preferred lifetime: 315360000
            Valid lifetime: 315360000
            Prefix length: 56
            Prefix address: 2a00:23c5:5501:bd00::

When the Hub is rebooted the DHCPv6 exchange is slightly different so this may be why a reboot resolves the problem for you. 

 

You mentioned in message 1 that you could see DHCPv6 messages in the log. Can you post those messages here as I'd be interested to see what they are. 

 

Regards

0 Ratings
Reply
yarrum
Aspiring Contributor
272 Views
Message 9 of 10

Re: Hub 6 and IPv6 loss on re-sync

smf22,

The logs are long, and contain identifying information, so I'll extract what seems relevant. Note that the logs are newest at the top.


On reboot, I get:


20:41:29, 12 Apr.,ppp1:The WAN DHCPv6 Client Process has successfully been launched on Vlan 36
20:41:29, 12 Apr.,BR_LAN: Allocated prefix = fdaa:bbcc:ddee::/64 (valid time = 4293967296 / preferred time = 4293967296)
20:41:29, 12 Apr.,BR_LAN: Allocated prefix = 2a00:23c5:6584:ff00::/64 (valid time = 2026291200 / preferred time = 2026291200)
20:41:29, 12 Apr.,BR_LAN: Allocated address = 2a00:23c5:6584:ff00:a608:f5ff:fe89:5d59 (valid time = 2026291200 / preferred time = 2026291200)
20:41:29, 12 Apr.,BR_LAN: Allocated prefix = 2a00:23c5:6584:ff00::/64 (valid time = 2026291200 / preferred time = 2026291200)
20:41:29, 12 Apr.,ppp1: Allocated prefix = 2a00:23c5:6584:ff01::/64 (valid time = 2026291200 / preferred time = 2026291200)
20:41:29, 12 Apr.,ppp1: Allocated prefix = 2a00:23c5:6584:ff00::/56 (valid time = 2026291200 / preferred time = 2026291200)
20:41:29, 12 Apr.,ppp1: Allocated address = 2a00:23c5:6584:ff01:a608:f5ff:fe89:5d57 (valid time = 2026291200 / preferred time = 2026291200)
20:41:29, 12 Apr.,ppp1: Allocated prefix = 2a00:23c5:6584:ff01::/64 (valid time = 2026291200 / preferred time = 2026291200)
20:41:29, 12 Apr.,ppp1:WAN DHCPv6 Mode : Statefull
20:41:28, 12 Apr.,BR_LAN: Allocated prefix = fdaa:bbcc:ddee::/64 (valid time = 4293967296 / preferred time = 4293967296)
20:41:28, 12 Apr.,BR_LAN: Allocated prefix = 2a00:23c5:6584:ff00::/64 (valid time = 2026291200 / preferred time = 2026291200)
20:41:28, 12 Apr.,BR_LAN: Allocated address = 2a00:23c5:6584:ff00:a608:f5ff:fe89:5d59 (valid time = 2026291200 / preferred time = 2026291200)
20:41:28, 12 Apr.,BR_LAN: Allocated prefix = 2a00:23c5:6584:ff00::/64 (valid time = 2026291200 / preferred time = 2026291200)
20:41:28, 12 Apr.,ppp1: Allocated prefix = 2a00:23c5:6584:ff01::/64 (valid time = 2026291200 / preferred time = 2026291200)
20:41:28, 12 Apr.,ppp1: Allocated prefix = 2a00:23c5:6584:ff00::/56 (valid time = 2026291200 / preferred time = 2026291200)
20:41:28, 12 Apr.,ppp1: Allocated address = 2a00:23c5:6584:ff01:a608:f5ff:fe89:5d57 (valid time = 2026291200 / preferred time = 2026291200)
20:41:28, 12 Apr.,ppp1: Allocated prefix = 2a00:23c5:6584:ff01::/64 (valid time = 2026291200 / preferred time = 2026291200)
20:41:28, 12 Apr.,ppp1:The WAN DHCPv6 Client Process has successfully been launched on Vlan 36
20:41:28, 12 Apr.,BR_LAN: Allocated prefix = fdaa:bbcc:ddee::/64 (valid time = 4293967296 / preferred time = 4293967296)
20:41:28, 12 Apr.,BR_LAN: Allocated prefix = 2a00:23c5:6584:ff00::/64 (valid time = 2026291200 / preferred time = 2026291200)
20:41:28, 12 Apr.,BR_LAN: Allocated prefix = fdaa:bbcc:ddee::/64 (valid time = 4293967296 / preferred time = 4293967296)
20:41:28, 12 Apr.,BR_LAN: Revoked prefix = 2a00:23c5:6584:ff00::/64 (valid time = 2026291200 / preferred time = 2026291200)
20:41:28, 12 Apr.,BR_LAN: Allocated address = 2a00:23c5:6584:ff00:a608:f5ff:fe89:5d59 (valid time = 2026291200 / preferred time = 2026291200)
20:41:28, 12 Apr.,BR_LAN: Allocated prefix = 2a00:23c5:6584:ff00::/64 (valid time = 2026291200 / preferred time = 2026291200)
20:41:28, 12 Apr.,ppp1: Allocated prefix = 2a00:23c5:6584:ff01::/64 (valid time = 2026291200 / preferred time = 2026291200)
20:41:28, 12 Apr.,ppp1: Allocated prefix = 2a00:23c5:6584:ff00::/56 (valid time = 2026291200 / preferred time = 2026291200)
20:41:28, 12 Apr.,ppp1: Allocated address = 2a00:23c5:6584:ff01:a608:f5ff:fe89:5d57 (valid time = 2026291200 / preferred time = 2026291200)
20:41:28, 12 Apr.,ppp1: Allocated prefix = 2a00:23c5:6584:ff01::/64 (valid time = 2026291200 / preferred time = 2026291200)
20:41:28, 12 Apr.,ppp1:WAN DHCPv6 Mode : Statefull
20:41:27, 12 Apr.,ppp1: Allocated prefix = 2a00:23c5:6584:ff00::/56 (valid time = 2026291200 / preferred time = 2026291200)
20:41:27, 12 Apr.,ppp1: Allocated prefix = 2a00:23c5:6584:ff00::/56 (valid time = 2026291200 / preferred time = 2026291200)
20:41:24, 12 Apr.,ppp1:The WAN DHCPv6 Client Process has successfully been launched on Vlan 36
00:03:39, 01 Jan.,ppp1:WAN DHCPv6 Mode : Statefull

After this, all other log info is LAN-side stuff. IPv6 is enabled and functional.


On disconnect/reconnect, I get something that starts out essentially the same, but "preferred time" then changes to 0:

20:00:01, 12 Apr.,ppp1:The WAN DHCPv6 Client Process has successfully been launched on Vlan 36
20:00:01, 12 Apr.,ppp1: Allocated prefix = 2a00:23c5:6584:ff01::/64 (valid time = 2836032704 / preferred time = 0)
20:00:01, 12 Apr.,ppp1: Allocated prefix = 2a00:23c5:6584:ff00::/56 (valid time = 2836032704 / preferred time = 0)
20:00:01, 12 Apr.,ppp1: Allocated address = 2a00:23c5:6584:ff01:a608:f5ff:fe89:5d57 (valid time = 2026291200 / preferred time = 2026291200)
20:00:01, 12 Apr.,ppp1: Allocated prefix = 2a00:23c5:6584:ff01::/64 (valid time = 2026291200 / preferred time = 2026291200)
20:00:01, 12 Apr.,BR_LAN: Allocated prefix = fdaa:bbcc:ddee::/64 (valid time = 4293967296 / preferred time = 4293967296)
20:00:01, 12 Apr.,BR_LAN: Allocated prefix = 2a00:23c5:6584:ff00::/64 (valid time = 2836032704 / preferred time = 0)
20:00:01, 12 Apr.,BR_LAN: Allocated address = 2a00:23c5:6584:ff00:a608:f5ff:fe89:5d59 (valid time = 2026291200 / preferred time = 2026291200)
20:00:01, 12 Apr.,BR_LAN: Allocated prefix = 2a00:23c5:6584:ff00::/64 (valid time = 2026291200 / preferred time = 2026291200)
20:00:01, 12 Apr.,ppp1:WAN DHCPv6 Mode : Statefull
20:00:00, 12 Apr.,BR_LAN: Allocated prefix = fdaa:bbcc:ddee::/64 (valid time = 4293967296 / preferred time = 4293967296)
20:00:00, 12 Apr.,BR_LAN: Allocated prefix = 2a00:23c5:6584:ff00::/64 (valid time = 2836032704 / preferred time = 0)
20:00:00, 12 Apr.,ppp1: Allocated prefix = 2a00:23c5:6584:ff01::/64 (valid time = 2836032704 / preferred time = 0)
20:00:00, 12 Apr.,ppp1: Allocated prefix = 2a00:23c5:6584:ff00::/56 (valid time = 2836032704 / preferred time = 0)
20:00:00, 12 Apr.,ppp1: Allocated prefix = 2a00:23c5:6584:ff00::/56 (valid time = 2836032704 / preferred time = 0)
20:00:00, 12 Apr.,:The LAN DHCP Server is active
20:00:00, 12 Apr.,ppp1: Allocated prefix = 2a00:23c5:6584:ff01::/64 (valid time = 2026291200 / preferred time = 2026291200)
20:00:00, 12 Apr.,ppp1: Allocated prefix = 2a00:23c5:6584:ff00::/56 (valid time = 2026291200 / preferred time = 2026291200)
20:00:00, 12 Apr.,ppp1: Allocated address = 2a00:23c5:6584:ff01:a608:f5ff:fe89:5d57 (valid time = 2026291200 / preferred time = 2026291200)
20:00:00, 12 Apr.,ppp1: Allocated prefix = 2a00:23c5:6584:ff01::/64 (valid time = 2026291200 / preferred time = 2026291200)
20:00:00, 12 Apr.,ppp1: Allocated prefix = 2a00:23c5:6584:ff01::/64 (valid time = 2026291200 / preferred time = 2026291200)
20:00:00, 12 Apr.,ppp1: Allocated prefix = 2a00:23c5:6584:ff00::/56 (valid time = 2026291200 / preferred time = 2026291200)
20:00:00, 12 Apr.,ppp1: Allocated address = 2a00:23c5:6584:ff01:a608:f5ff:fe89:5d57 (valid time = 2026291200 / preferred time = 2026291200)
20:00:00, 12 Apr.,ppp1: Allocated prefix = 2a00:23c5:6584:ff01::/64 (valid time = 2026291200 / preferred time = 2026291200)
20:00:00, 12 Apr.,BR_LAN: Allocated prefix = fdaa:bbcc:ddee::/64 (valid time = 4293967296 / preferred time = 4293967296)
20:00:00, 12 Apr.,BR_LAN: Allocated prefix = 2a00:23c5:6584:ff00::/64 (valid time = 2026291200 / preferred time = 2026291200)
20:00:00, 12 Apr.,BR_LAN: Allocated address = 2a00:23c5:6584:ff00:a608:f5ff:fe89:5d59 (valid time = 2026291200 / preferred time = 2026291200)
20:00:00, 12 Apr.,BR_LAN: Allocated prefix = 2a00:23c5:6584:ff00::/64 (valid time = 2026291200 / preferred time = 2026291200)
20:00:00, 12 Apr.,BR_LAN: Allocated prefix = fdaa:bbcc:ddee::/64 (valid time = 4293967296 / preferred time = 4293967296)
20:00:00, 12 Apr.,BR_LAN: Allocated prefix = 2a00:23c5:6584:ff00::/64 (valid time = 2026291200 / preferred time = 2026291200)
20:00:00, 12 Apr.,BR_LAN: Allocated address = 2a00:23c5:6584:ff00:a608:f5ff:fe89:5d59 (valid time = 2026291200 / preferred time = 2026291200)
20:00:00, 12 Apr.,BR_LAN: Allocated prefix = 2a00:23c5:6584:ff00::/64 (valid time = 2026291200 / preferred time = 2026291200)
20:00:00, 12 Apr.,ppp1:The WAN DHCPv6 Client Process has successfully been launched on Vlan 36

Then the following basically repeats every minute, with the "valid time" counting down 60,000,000 each time. When it reaches zero, these logs stop.

20:02:01, 12 Apr.,BR_LAN: Allocated prefix = fdaa:bbcc:ddee::/64 (valid time = 4293967296 / preferred time = 4293967296)
20:02:01, 12 Apr.,BR_LAN: Allocated prefix = 2a00:23c5:6584:ff00::/64 (valid time = 2716032704 / preferred time = 0)
20:02:01, 12 Apr.,BR_LAN: Allocated address = 2a00:23c5:6584:ff00:a608:f5ff:fe89:5d59 (valid time = 2716032704 / preferred time = 0)
20:02:01, 12 Apr.,BR_LAN: Allocated prefix = 2a00:23c5:6584:ff00::/64 (valid time = 2716032704 / preferred time = 0)
20:02:01, 12 Apr.,ppp1: Allocated prefix = 2a00:23c5:6584:ff01::/64 (valid time = 2716032704 / preferred time = 0)
20:02:01, 12 Apr.,ppp1: Allocated prefix = 2a00:23c5:6584:ff00::/56 (valid time = 2716032704 / preferred time = 0)
20:02:01, 12 Apr.,ppp1: Allocated address = 2a00:23c5:6584:ff01:a608:f5ff:fe89:5d57 (valid time = 2716032704 / preferred time = 0)
20:02:01, 12 Apr.,ppp1: Allocated prefix = 2a00:23c5:6584:ff01::/64 (valid time = 2716032704 / preferred time = 0)
20:02:01, 12 Apr.,ppp1:The WAN DHCPv6 Client Process has successfully been launched on Vlan 36
20:02:01, 12 Apr.,BR_LAN:LAN Router Advertisement Setting Updated : M_flag = 0, O_flag = 1
20:02:00, 12 Apr.,BR_LAN: Allocated prefix = fdaa:bbcc:ddee::/64 (valid time = 4293967296 / preferred time = 4293967296)
20:02:00, 12 Apr.,BR_LAN: Allocated prefix = 2a00:23c5:6584:ff00::/64 (valid time = 2716032704 / preferred time = 0)
20:02:00, 12 Apr.,BR_LAN: Allocated address = 2a00:23c5:6584:ff00:a608:f5ff:fe89:5d59 (valid time = 2716032704 / preferred time = 0)
20:02:00, 12 Apr.,BR_LAN: Allocated prefix = 2a00:23c5:6584:ff00::/64 (valid time = 2716032704 / preferred time = 0)
20:02:00, 12 Apr.,ppp1: Allocated prefix = 2a00:23c5:6584:ff01::/64 (valid time = 2716032704 / preferred time = 0)
20:02:00, 12 Apr.,ppp1: Allocated prefix = 2a00:23c5:6584:ff00::/56 (valid time = 2716032704 / preferred time = 0)
20:02:00, 12 Apr.,ppp1: Allocated address = 2a00:23c5:6584:ff01:a608:f5ff:fe89:5d57 (valid time = 2716032704 / preferred time = 0)
20:02:00, 12 Apr.,ppp1: Allocated prefix = 2a00:23c5:6584:ff01::/64 (valid time = 2716032704 / preferred time = 0)
20:02:00, 12 Apr.,ppp1:WAN DHCPv6 Mode : Statefull
20:02:00, 12 Apr.,BR_LAN: Allocated prefix = fdaa:bbcc:ddee::/64 (valid time = 4293967296 / preferred time = 4293967296)
20:02:00, 12 Apr.,BR_LAN: Allocated prefix = 2a00:23c5:6584:ff00::/64 (valid time = 2716032704 / preferred time = 0)
20:02:00, 12 Apr.,ppp1: Allocated prefix = 2a00:23c5:6584:ff01::/64 (valid time = 2716032704 / preferred time = 0)
20:02:00, 12 Apr.,ppp1: Allocated prefix = 2a00:23c5:6584:ff00::/56 (valid time = 2716032704 / preferred time = 0)
20:02:00, 12 Apr.,ppp1: Allocated prefix = 2a00:23c5:6584:ff00::/56 (valid time = 2716032704 / preferred time = 0)

 

 

0 Ratings
Reply
yarrum
Aspiring Contributor
235 Views
Message 10 of 10

Re: Hub 6 and IPv6 loss on re-sync

Ok, I have a theory.

On boot-up, the router doesn't have any IPv6 address, so it's happy with the one it's given.

On disconnect/reconnect, it has an "old" IPv6 address which it wants to deprecate when it has a new one with the new connection.

The problem is that the new one is the same as the old one, so the router is deprecating it straight away.

 

I think the logs I posted before were "too late" in the process. Some more entries. I think the key one is "WAN DHCPv6 Client Prefix" indicating that my box is getting a DHCPv6 reply (it is the only time this message appears):

 

19:59:25, 12 Apr.,ppp1: Allocated prefix = 2a00:23c5:6584:ff01::/64 (valid time = 2845032704 / preferred time = 0)
19:59:25, 12 Apr.,ppp1: Allocated prefix = 2a00:23c5:6584:ff00::/56 (valid time = 2026291200 / preferred time = 2026291200)
19:59:25, 12 Apr.,ppp1: Allocated prefix = 2a00:23c5:6584:ff00::/56 (valid time = 2026291200 / preferred time = 2026291200)
19:59:25, 12 Apr.,:WAN DHCPv6 Client Prefix : 2a00:23c5:6584:ff00::/56 (valid time = 315360000 / preferred time = 315360000)
19:59:13, 12 Apr.,:DHCP Confirmation of Request
19:58:58, 12 Apr.,ppp1: Allocated prefix = 2a00:23c5:6584:ff01::/64 (valid time = 2845032704 / preferred time = 0)
19:58:58, 12 Apr.,ppp1: Allocated prefix = 2a00:23c5:6584:ff00::/56 (valid time = 2845032704 / preferred time = 0)
19:58:58, 12 Apr.,ppp1: Allocated prefix = 2a00:23c5:6584:ff00::/56 (valid time = 2845032704 / preferred time = 0)
19:58:58, 12 Apr.,ppp1:The WAN DHCPv6 Client Process has successfully been launched on Vlan 36
19:58:58, 12 Apr.,:WAN: SENSING AUTO VDSL

 

0 Ratings
Reply