Tue Apr 18 18:29:55 2023 daemon.err odhcpd[1840]: Failed to send to ff02::1%lan@br-lan (Network unreachable)
Tue Apr 18 18:30:11 2023 daemon.err odhcpd[1840]: Failed to send to ff02::1%lan@br-lan (Network unreachable)
Tue Apr 18 18:30:27 2023 daemon.err odhcpd[1840]: Failed to send to ff02::1%lan@br-lan (Network unreachable)
Tue Apr 18 18:30:43 2023 daemon.err odhcpd[1840]: Failed to send to ff02::1%lan@br-lan (Network unreachable)
Tue Apr 18 18:30:59 2023 daemon.err odhcpd[1840]: Failed to send to ff02::1%lan@br-lan (Network unreachable)
Tue Apr 18 18:31:15 2023 daemon.err odhcpd[1840]: Failed to send to ff02::1%lan@br-lan (Network unreachable)
Tue Apr 18 18:31:31 2023 daemon.err odhcpd[1840]: Failed to send to ff02::1%lan@br-lan (Network unreachable)
Hundreds of them, every 16 seconds...
I just installed OpenWrt a few days ago, on v22.03.4.
I have a Raspberry Pi set up running Pi-hole and Unbound on a LAN port on the router (Archer C7 v2).
I looked at these threads, but I still don't have an answer as to what to do to fix this issue.
I turned off IPv6 in a few places, and I'd like to turn it off everywhere in OpenWrt (I wish there was a master switch for this in the OpenWrt GUI...), but I'm not sure where all the places are to turn it off.
Is your goal to truly not use IPv6 at all or just turn it off for the purposes of troubleshooting this issue?
The ff02::1 address is IPv6 multicast for all nodes on a local segment. If you truly want IPv6 disabled on your network, you likely will want to stop & disable the odhcpd service.
However, I am not aware of what repercussions there are (if any) with disabling that service entirely.
Sounds like it is an IPv6 issue, then, I'm guessing, given that "The ff02::1 address is IPv6 multicast for all nodes on a local segment." and other info supports this notion.
Based on that thread you linked, it looks like I can do the following?
uci set 'network.lan.ipv6=0'
uci set 'network.wan.ipv6=0'
uci set 'dhcp.lan.dhcpv6=disabled'
/etc/init.d/odhcpd disable
/etc/init.d/odhcpd stop
uci commit
That looks legitimate if your goal is to disable IPv6. I generally would recommend against disabling IPv6 these days, but I am still fuzzy on your ultimate goal so perhaps I am speaking out of turn.
Haha, my goal is to find out the cause of these errors. If they're a result of IPv6, then, yes, I want to completely disable IPv6 in OpenWrt. I'm fine with IPv6 being disabled on my network.
Actually, I'll just give it a try with those commands I posted and double check the syntax, thanks for the link to that thread.
I feel like this was a chicken--egg situation. Perhaps I misunderstood, but it sounded like the errors began when you started trying to disable IPv6 (for whatever reason). But then you wanted to avoid the errors, so you have to go the extra mile to fully disable IPv6.
If that was the case, my recommendation would have been to just undo whatever you started modifying that was disabling IPv6 and just embrace it, at least in a LL (and perhaps ULA) setup. Basically the old "if it ain't broke, don't fix it" stance.
But it's your network and if disabling IPv6 is the goal, give those commands a shot and let us know how it goes.
I dunno, maybe I wasn't clear. But I did title this thread using the words "syslog errors":
Syslog errors "network unreachable" (failed to send packet: Network unreachable), but network is fine?
I provided this info:
I turned off IPv6 in a few places...
...after I posed the question asking about the cause of the syslog errors because the links I'd provided suggested that it might be an IPv6 issue, but I wasn't sure, hence the original question.
And I posted this:
No, but I hadn't looked at syslog before now.
...in response to your question "Were you seeing these errors prior to attempting to disable any IPv6 functionality?" I'd obviously read the syslog before starting this thread, so that shouldn't lead to any confusion.
Anyway, I will give those commands a try and see if the errors in the syslog will go away (which will hopefully achieve my goal of finding out the errors in the syslog, hehe).
Thanks again for the link to that thread, I think that they'll fix it. I do appreciate your help.
ip -6 addr show dev br-lan scope link
shows nothing.
But, interestingly, after disabling IPv6, I performed a speed test and got a highest-ever speed of 273.05Mbps. Even faster than I had with the stock TP-Link firmware on my Archer C7 v2 (a high of 270). I'd been suck around 200-220 for awhile after installing OpenWrt 22.03.4. I wonder if there's any correlation with disabling IPv6?
But, boy oh boy, would it ever be nice to just have a master switch in the OpenWrt web GUI that we could toggle "on / off" to "Turn Off IPv6 Completely"... That would be very nice.
It's 2023. We have waited for such a long time that many ISP provide IPv6 connectivity and at leased lot of bigger networks run dual stack. Disabling IPv6 is not a recommended option.
I would propose you go a few steps back and ensure that the default IPv6 settings are restored. The defaults are just fine and work out of the box. (Even if you have no IPv6 upstream everything works just fine.)
