ipv6 broken: radvd: can't join ipv6-allrouters on <interface>

[Irata]

I can confirm this must be an issue.

I have exactly the same situation, after around 6-7 hours of running, radvd spams the logs with "can't join ipv6-allrouters". IPv6 stops works as all clients release their IPv6 address since no more router advertisements are ever sent.
As an interim fix, I stop and start radvd via cron every 6 hours, a click of restart does not fix it. It has to be a stop, sleep 1 second, and a start. Is there some memory leak in radvd? Or binding and not releasing to the interface? There is radvd 2.18 available now with numerous fixes.

This issue does unfortunately break IPv6 when using un-managed router advertisements.

I have turned up logging levels, but it does not add anything more related to radvd.

[strangegopher]

@Irata thank you, good to know that I am not the only one.
Can someone from pfsense team let us know if a bug report needs to be opened?

[Irata]

@strangegopher thanks, glad I found your post as I also thought it was just me!

It happens on all interfaces at the same time, so I took a packet capture on a quiet subnet - but nothing of interest again, can just see when the router advertisements stop.

Sadly my restart workaround using cron has side effects, any active IPv6 connections are dropped each time it runs. And one Android device even disconnects from WiFi each time radvd is restarted, it treats a loss of IPv6 as a network problem, bizarre but true.

Be interested to hear if anyone using radvd and IPv6 does not have this issue? Check Routing logs in System Logs.

I'm at a loss what else to do. It's interesting that a periodic restart masks the problem, does that point to radvd being the problem?

[maverick_slo]

I don't have this issue.
I'm on 2.5 with uptime 3 days.

[strangegopher]

@maverick_slo do u have ipv6?

[maverick_slo]

Since 2013

[arafey]

I've been having this problem as well and I also noticed that it's about 6 hours before IPv6 suddenly breaks. This should definitely be fixed before 2.5.0 is released.

[crimper]

I am having the same issue. IPv6 would stop working within 24 hours. I backup the config.xml from the 2.5 and restored the file to a 2.4.4_p2 and it does not have the problem.

[Irata]

I'm not sure how to find what's common.

I'm running pfsense within VMware ESXi and have this issue. Are others with this issue the same?

I can also confirm the latest 2.4 branch does not have this issue with the same config.

[strangegopher]

I am running it on baremetal dell box but I am using chelsio 10G sfp+ nic.

[strangegopher]

@jimp sorry for the ping but do u have any idea why ipv6 stops working?

[motific]

How is it on a fresh 2.5 install with the old config?

I’ve just had some bad behaviour with radvd not responding at all (not quite the same as your issue) and that has cleared it.

[kiokoman]

i have similar behavior on my log

Jun 6 21:32:29 	radvd 	66014 	resuming normal operation
Jun 6 21:32:29 	radvd 	66014 	attempting to reread config file
Jun 6 18:57:34 	radvd 	66014 	resuming normal operation
Jun 6 18:57:34 	radvd 	66014 	attempting to reread config file
Jun 6 14:01:49 	radvd 	65728 	version 2.17 started 
Jun 6 14:00:39 	radvd 	67952 	can't join ipv6-allrouters on igb2
Jun 6 14:00:39 	radvd 	67952 	can't join ipv6-allrouters on ath0_wlan0
Jun 6 14:00:33 	radvd 	67952 	can't join ipv6-allrouters on igb2
Jun 6 14:00:22 	radvd 	67952 	can't join ipv6-allrouters on igb2
Jun 6 14:00:20 	radvd 	67952 	can't join ipv6-allrouters on ath0_wlan0
Jun 6 14:00:08 	radvd 	67952 	can't join ipv6-allrouters on igb2
Jun 6 14:00:01 	radvd 	67952 	can't join ipv6-allrouters on ath0_wlan0
Jun 6 13:59:53 	radvd 	67952 	can't join ipv6-allrouters on ath0_wlan0
Jun 6 13:59:53 	radvd 	67952 	can't join ipv6-allrouters on igb2
Jun 6 13:59:40 	radvd 	67952 	can't join ipv6-allrouters on ath0_wlan0
Jun 6 13:59:36 	radvd 	67952 	can't join ipv6-allrouters on igb2
Jun 6 13:59:30 	radvd 	67952 	can't join ipv6-allrouters on igb2
Jun 6 13:59:25 	radvd 	67952 	can't join ipv6-allrouters on ath0_wlan0

igb0 is wan
igb1 is lan
on igb2 i have only 1 pc, a server connected with static ipv6
on ath0_wlan0 i have a couple of notebook with windows 10 and a couple of android phone

[Irata]

A fresh install causes the same error for me, once stateless IPv6 is setup. I can't find a stable working system whatever I do, other than back to 2.4.

Because I'm using an ESXi testbed, it's easy to spin up new installs.

I do think there is something fundamental here, given the reports from wide ranging setups.

[kiokoman]

the error is generated from device-bsd44.c, a patch it's inside the port of radvd for freebsd
tracking back there was similar problem. related Bug #2878 https://redmine.pfsense.org/issues/2878 from 2013

/* XXX: See pfSense ticket #2878 */
+	setsockopt(sock, IPPROTO_IPV6, IPV6_LEAVE_GROUP, &mreq, sizeof(mreq));
+
+	if (setsockopt(sock, IPPROTO_IPV6, IPV6_JOIN_GROUP,
+			&mreq, sizeof(mreq)) < 0) {
+		flog(LOG_ERR, "can't join ipv6-allrouters on %s", iface->props.name);
+		return (-1);
+ }

maybe it's time for a new ticket
https://redmine.pfsense.org/issues/9577

[strangegopher]

idk if we open a ticket devs might just ignore it, first we should get devs on the forums to tell us if we need to open a bug.

[motific]

@strangegopher - they're aware of it, one of the devs referred to the ticket in a thread with an issue I'm having.

[maverick_slo]

Now it hit me too:

Jun 29 07:17:29 radvd 62926 can't join ipv6-allrouters on hn0.10
Jun 29 07:15:22 radvd 62926 can't join ipv6-allrouters on hn0.10
Jun 29 07:15:00 radvd 62926 can't join ipv6-allrouters on hn0.9
Jun 29 07:13:07 radvd 62926 can't join ipv6-allrouters on hn0.7
Jun 29 07:12:47 radvd 62926 can't join ipv6-allrouters on hn0.10
Jun 29 07:11:25 radvd 62926 can't join ipv6-allrouters on hn0.8
Jun 29 07:11:23 radvd 62926 can't join ipv6-allrouters on hn0.9
Jun 29 07:10:22 radvd 62926 can't join ipv6-allrouters on hn0.10
Jun 29 07:08:10 radvd 62926 can't join ipv6-allrouters on hn0.10

[kiokoman]

welcome to the party !

[Irata]

@maverick_slo made any changes recently, or added any new IPv6 devices?