Posted: Fri Aug 05, 2022 16:31 Post subject: [3rd party ISSUE] IPv6 radvd error.
I've been having problems with my IPv6 installation. Among other things, I figured out that if I have Static DNS 1 and Static DNS 2 entered on the Setup-IPv6 page, radvd wasn't able to run correctly. I think it was getting initial DNS entries from the upstream router advertisement, but I'm not sure. Once I removed the static DNS entries from the interface radvd runs again and clients on my local network receive router advertisements.
root@Netgear-R7000:~# radvd --debug=5 -C /tmp/radvd.conf
[Aug 05 08:00:06] radvd (19543): too many addresses in RDNSS section
[Aug 05 08:00:06] radvd (19543): exiting, failed to read config file
This seems like a bug in radvd to me. Here's the announcement I'm seeing from my ISP router.
Code:
root@Netgear-R7000:~# radvdump
#
# radvd configuration generated by radvdump 2.19
# based on Router Advertisement from fe80::22c:c8ff:fe42:24bf
# received by interface vlan2
#
RDNSS (Recursive DNS server) definitions are of the form:
RDNSS ip [ip] [ip] { list of rdnss specific options
};
That's a reasonable attitude to take, but I'd say that DDWRT should somehow figure out if there are going to be too many RDNSS entries when it creates the /tmp/radvd.conf file and not create a file that's going to crash radvd.
It would be different if I was creating a custom configuration for the Router Advertisement Daemon, but I was only enabling it, not creating a custom configuration.
Joined: 31 Jul 2021 Posts: 2146 Location: All over YOUR webs
Posted: Sat Aug 06, 2022 8:38 Post subject:
@WCBonner
radvd (like many DD-WRT components) is not maintained/developed by DD-WRT so your request while fair and indeed radvd should not crash but instead error out gracefully does not belong in these boards.
Rather this belongs at https://github.com/radvd-project/radvd more specifically you should open a request at https://github.com/radvd-project/radvd/issues/new and follow the projects requirements if any to file the report. Ensure first no existing issue upstream already covers the report, if one exists you should file a proper report and not a me too report which will likely be disregarded.
Once that is solved upstream, next time a radvd has a release which contains the fix, will be pulled into DD-WRT and the issue solved that way, otherwise, the issue will remain DD-WRT side forever.
Or, you compare the tree in DD-WRT and the upstream tree and see that some upstream patches aren't applied that could be culprit. _________________ "The woods are lovely, dark and deep,
But I have promises to keep,
And miles to go before I sleep,
And miles to go before I sleep." - Robert Frost
"I am one of the noticeable ones - notice me" - Dale Frances McKenzie Bozzio
Or not, DD-WRT is running stable radvd 2.19 anything on upstream master after the fact no longer applies post 2.19 and DD-WRT and therefore moot. And this isn't like dnsqmasq which is running master alpha code and not a specific public release.
Also to note, it seems that DD-WRT is the only custom firmware still using radvd to begin with. So, maybe there's also a possibility to remove a problematic package and change how router advertisements are handled for IPv6 - instead using dnsmasq or dhcp6c/dhcp6s, and decrease firmware image sizes (or not). _________________ "The woods are lovely, dark and deep,
But I have promises to keep,
And miles to go before I sleep,
And miles to go before I sleep." - Robert Frost
"I am one of the noticeable ones - notice me" - Dale Frances McKenzie Bozzio
Is the method of using dnsmasq instead of radvd to go to Setup->IPv6 and disable the Router Advertisement Daemon (radvd), then go to Services->Services, find the Dnsmasq Infrastructure section, and add enable-ra to a line in the Additional Options section?
After doing that, should I be able to see router advertisements on my client machine via the radvdump command that look very similar to the current advertisements I'm seeing?
Joined: 31 Jul 2021 Posts: 2146 Location: All over YOUR webs
Posted: Sat Aug 06, 2022 17:00 Post subject:
dale_gribble39 wrote:
Also to note, it seems that DD-WRT is the only custom firmware still using radvd to begin with. So, maybe there's also a possibility to remove a problematic package and change how router advertisements are handled for IPv6 - instead using dnsmasq or dhcp6c/dhcp6s, and decrease firmware image sizes (or not).
Sausage factory, it will reduce very very little to nothing, we and this is after I started doing my work and in relation to it, removed outdated and no longer used components in the past and reduction was zero on final FW image and even amount of blocks used. and besides its not me you need to convince.
In any case I dont see this bug report upstream and I wont do it as I dont have a way to duplicate, so another bug for the ages and this is the only important question here the rest of the sausage factory is meaningless.
Is the method of using dnsmasq instead of radvd to go to Setup->IPv6 and disable the Router Advertisement Daemon (radvd), then go to Services->Services, find the Dnsmasq Infrastructure section, and add enable-ra to a line in the Additional Options section?
It required more than just the simple enable-ra to get advertisements showing up on my clients and global IPv6 addresses to be configured. I got things working by adding these three lines. I copied them from elsewhere, so don't fully understand what I've done, but am happy with the results. I was able to do it without the ra-param line. The ra-param line seemed to increase the frequency of announcements, making my network faster to configure IPv6.
Joined: 31 Jul 2021 Posts: 2146 Location: All over YOUR webs
Posted: Sat Aug 06, 2022 17:53 Post subject:
WCBonner wrote:
It required more than just the simple enable-ra to get advertisements showing up on my clients and global IPv6 addresses to be configured. I got things working by adding these three lines. I copied them from elsewhere, so don't fully understand what I've done, but am happy with the results. I was able to do it without the ra-param line. The ra-param line seemed to increase the frequency of announcements, making my network faster to configure IPv6.
Im glad you managed to solve it sort of, however, are you prepared to do a radvd bug report upstream or are you happy with unsolved bugs as a result of no action?
It required more than just the simple enable-ra to get advertisements showing up on my clients and global IPv6 addresses to be configured. I got things working by adding these three lines. I copied them from elsewhere, so don't fully understand what I've done, but am happy with the results. I was able to do it without the ra-param line. The ra-param line seemed to increase the frequency of announcements, making my network faster to configure IPv6.
Im glad you managed to solve it sort of, however, are you prepared to do a radvd bug report upstream or are you happy with unsolved bugs as a result of no action?
I opened an issue on GitHub before I spent the time figuring out dnsmasq router advertisements. I didn't find something similar in any previous issues, open or closed. I'm hoping that I'll receive a response of some sort. If I have time in the next week, I may browse the code and see if I can provide a solution. https://github.com/radvd-project/radvd/issues/182
