05-31-2017 02:01 PM
What would be helpful is showing the effects of both states. The working and non working states.
Also if you're using Windows:
netsh interface ipv6 show neighbors
You might want to take a look at the routing table for the device having problems. Keep in mind on the neighbor table there should be a LL address that belong to Comcast, you should be able to ping the address as well with no problems.
If you suspect MTU issues, use ping to check the endpoints.
05-31-2017 02:16 PM
06-02-2017 11:34 AM - edited 06-02-2017 02:01 PM
To clarify my prevous comment:
I tried your exact config and no dice for me. It must be either my modem (sb-6183) or Comcast issue and
the er-x works fine with no hwnat (ipv4 and ipv6) as does my RB750GR3 (which isn't using hwnat - just a
different method to accomplish something similiar).
Thanks for your help. I appreciate it.
06-02-2017 01:36 PM
I'd like to just report in that I'm using ER-X with a motorolla surfboard 6141 modem, with hwnat *off*, and it's working ipv6 just fine.
Probably not useful, but an anecdote none the less.
06-03-2017 03:40 AM
I also have a SB-6141, I could test this out later in the week with the ER-X.
Another thing might want to keep in mind is that Comcast-wise the equipment behind your cable modem varies per location. This could cause problems with reproducing issues.
06-03-2017 11:00 AM
Here's what I see so far. Apparently, most ER-X users are working just fine on Comcast with hwnat enabled. Some, however, are having problems, apparently with LAN clients not getting (or losing) an IPv6 address. It
might help the ubnt folks if we had a little data from those NON-working systems.
Here are some of the differences we know of between "it works" and "it doesn't".
1) Geography. As @unknownzer pointed out, the upstream equipment at Comcast
in different geographies may vary, and there could be an interoperability
problem there. If so, you might expect the problem systems to be clustered.
An unexpected DHCP source port number was mentioned in an earlier thread,
2) Modems. There are reports of both problems and no problems with the SB6183.
We have had no apparent problem with hwnat enabled on both an SB6121 and an
SB6183. It's unclear whether anyone IS having a problem with hwnat enabled
on an SB6121 or SB6141 (or any other modem).
3) config.boot. @fibroce had problems using the same config.boot we use, and
we have not had problems. We have also both used the SB6183 with that
config.boot. See #1.
- Neighbor count or churn? No data.
- Comcast service tier? Little, if any, data.
I'd be curious to know from the ubnt folks how hwnat COULD interfere with IPv6
(or, maybe more specifically, DHCPv6).
06-03-2017 01:44 PM
1) I am in Johns Creek, GA (North metro Atlanta)
3) Running a slighty modified version of the one Steve Jenkins posted (on github) and here. Just
deleted the second network and changed the IP addresses. Works great with no hwnat.
4) On 300/30 Comcast residental tier. I get 361mb/s / 30 mb on speedtest.net. (using RB750GR3
neighbors - no data as I am not using er-x at moment. I can add that later.
06-03-2017 08:01 PM
As another reference point, I just updated my EdgeRouter X with the 1.9.7-alpha3 FW. I have hwnat enabled on a Comcast residential network in the Seattle, WA area. DHCPv6 seems to be working fine.
06-03-2017 08:29 PM
Steve must be using a different modem to get 1gb. The sb6183 is only
capable of around 430mb.
I loaded the 1.9.7 alpha3 firmware and still no ipv6 with hwnat enabled.
07-06-2017 07:08 PM
Unfortunately another "me too".
I'm running on Comcast with a SB6141 modem.
When I turn on hwnat I can't get an IPv6 address on boot.
Turning this off fixes it.
07-07-2017 06:20 AM
This doesn’t appear to be just a Comcast issue. I have a second location which is in Charter in the St. Louis area and the config is the same other than Charter gives a /56 PD and Comcast gives a /64. In both cases it stops working when HWNAT is enabled and the DHCPv6 traffic is being silently dropped (or ignored) by the ERX. The cable modems are different in both cases as well. An Arris 6190 in the Comcast case and an Arris TM1602 in the Charter case.
07-07-2017 06:26 AM
I have not experimented in the last week or so but Comcast ipv6 works fine with my rb-750gr3.
I still believe there is a solution for the ER-X and hwnat. I will continue the search.