IPv6 has stopped working

General discussion
1

IPv6 has worked fine on my Omnia since I got it - until the last few days. Now the dashboard reports “Connected: NO”. A laptop plugged directly into the cable modem gets an IPv6 address just fine.

I don’t have anything special in my configs, it’s pretty much out of the box:

type config interface 'wan'
        option ipv6 '1'
        option device 'eth2'
        option proto 'dhcp'

config interface 'wan6'
        option device '@wan'
        option proto 'dhcpv6'
        option reqaddress 'try'
        option reqprefix 'auto'

I do see this in the log:

Nov 21 23:06:46 turris odhcp6c[9716]: Failed to send RS (Address not available)
Nov 21 23:06:46 turris odhcp6c[9716]: Failed to send SOLICIT message to ff02::1:2 (Address not available)
Nov 21 23:06:47 turris odhcp6c[9716]: Failed to send SOLICIT message to ff02::1:2 (Address not available)

ip tells me:

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 state UNKNOWN qlen 1000
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1508 state UP qlen 1024
    inet6 fe80::da58:d7ff:fe01:205c/64 scope link 
       valid_lft forever preferred_lft forever
4: eth2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 state UP qlen 1024
    inet6 fe80::da58:d7ff:fe01:205d/64 scope link 
       valid_lft forever preferred_lft forever
14: br-guest-turris: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 state UP qlen 1000
    inet6 fd78:bb31:9f8:10::1/64 scope global noprefixroute 
       valid_lft forever preferred_lft forever
    inet6 fe80::4f0:21ff:fe45:c6a4/64 scope link 
       valid_lft forever preferred_lft forever
24: br-lan: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 state UP qlen 1000
    inet6 fd78:bb31:9f8::1/60 scope global noprefixroute 
       valid_lft forever preferred_lft forever
    inet6 fe80::da58:d7ff:fe01:205c/64 scope link 
       valid_lft forever preferred_lft forever
25: wlan0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 state UP qlen 1000
    inet6 fe80::6f0:21ff:fe45:d16d/64 scope link 
       valid_lft forever preferred_lft forever
26: wlan1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 state UP qlen 1000
    inet6 fe80::6f0:21ff:fe45:c6a4/64 scope link 
       valid_lft forever preferred_lft forever
27: guest_turris_1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 state UP qlen 1000
    inet6 fe80::4f0:21ff:fe45:c6a4/64 scope link 
       valid_lft forever preferred_lft forever

Has anybody seen anything like this?

Thanks!

2

OK, I kept on searching and found a solution…Comcast made a change and I had to adapt the firewall to match…the magic answer was at:

with the specific solution at:

Deleting this line:

	option src_ip 'fc00::/6'

From the Allow-DHCPv6 rule in /etc/config/firewall did the trick.

Sorry for the noise, I should have kept digging first.

3

Actually you found a “bug” (wrong configuration) that has been solved in OpenWrt since some time but is still open for TurrisOS.
Bug: Firewall: Default Allow-DHCPv6 rule option src_ip 'fc00::/6' prevents receiving ipv6 DHCP from ISP · Issue #5066 · openwrt/openwrt · GitHub → firewall: config: remove restictions on DHCPv6 allow rule by sdhz151 · Pull Request #26 · sdhz153/openwrt · GitHub

It hast the following changes:

From b089ceff2e8148e4e4a54c44d27eac5758d1f333 Mon Sep 17 00:00:00 2001
From: Tiago Gaspar <tiagogaspar8@gmail.com>
Date: Wed, 4 May 2022 10:36:07 +0100
Subject: [PATCH] config: remove restictions on DHCPv6 allow rule

Remove restrictions on source and destination addresses, which aren't
specified on RFC8415, and for some reason in openwrt are configured
to allow both link-local and ULA addresses.
As cleared out in issue #5066 there are some ISPs that use Gloabal
Unicast addresses, so fix this rule to allow them.

Fixes: #5066

Signed-off-by: Tiago Gaspar <tiagogaspar8@gmail.com>
---
 root/etc/config/firewall | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/root/etc/config/firewall b/root/etc/config/firewall
index f4a3322..b9a4647 100644
--- a/root/etc/config/firewall
+++ b/root/etc/config/firewall
@@ -54,13 +54,11 @@ config rule
 	option target		ACCEPT
 
 # Allow DHCPv6 replies
-# see https://dev.openwrt.org/ticket/10381
+# see https://github.com/openwrt/openwrt/issues/5066
 config rule
 	option name		Allow-DHCPv6
 	option src		wan
 	option proto		udp
-	option src_ip		fc00::/6
-	option dest_ip		fc00::/6
 	option dest_port	546
 	option family		ipv6
 	option target		ACCEPT
-- 
2.34.1

So if others find this thread - maybe also remove the option dest_ip-part.

4

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