Bind failures following update/reboot w/ 9.18.1

[Philip Prindeville]

My MTU is 1500 bytes, so I don't think that's the problem.

But UDP can fragment via IP...


> On May 13, 2022, at 10:34 AM, Greg Choules <gregchoules+bindusers at googlemail.com> wrote:
> 
> Hi Philip.
> Can you run packet captures? I'm running 9.18.0 (close enough?) in Docker and just traced what happens going from "dnssec-validation no;" to "dnssec-validation auto;" It makes a DNSKEY query for "." to one of the roots. The response size was over 900 bytes, so depending on what UDP payload size is advertised there might need to be some retrying over TCP. But you'll only know whether that is happening from a pcap.
> So I'd say.. check EDNS payload size, check what your firewall(s) is/are prepared to let through, check whether DNS/TCP is allowed at all, check if something is doing IP fragmentation (though I wouldn't expect this to come into play with a packet ~1k).
> 
> I hope some of that is useful.
> Cheers, Greg
> 
> On Fri, 13 May 2022 at 17:07, Philip Prindeville <philipp_subx at redfish-solutions.com> wrote:
> After rebooting my OpenWRT router with Bind 9.18.1 yesterday, I started seeing a lot of:
> 
> 
> May 12 19:24:06 OpenWrt named[11061]: validating ./NS: no valid signature found
> May 12 19:24:06 OpenWrt named[11061]: validating net/DS: no valid signature found
> May 12 19:24:06 OpenWrt named[11061]: no valid RRSIG resolving './NS/IN': 192.203.230.10#53
> May 12 19:24:06 OpenWrt named[11061]: no valid RRSIG resolving 'net/DS/IN': 8.8.4.4#53
> May 12 19:24:06 OpenWrt named[11061]: validating com/DS: no valid signature found
> May 12 19:24:06 OpenWrt named[11061]: no valid RRSIG resolving 'com/DS/IN': 8.8.4.4#53
> May 12 19:24:06 OpenWrt named[11061]: validating net/DS: no valid signature found
> May 12 19:24:06 OpenWrt named[11061]: no valid RRSIG resolving 'net/DS/IN': 66.232.64.10#53
> May 12 19:24:06 OpenWrt named[11061]: validating com/DS: no valid signature found
> May 12 19:24:06 OpenWrt named[11061]: no valid RRSIG resolving 'com/DS/IN': 66.232.64.10#53
> 
> 
> In my options, I had:
> 
> dnssec-validation auto;
> 
> But had to turn this off.  It had been working.  This is a production firewall/router.
> 
> What troubleshooting should I do to fix this?
> 
> I had tried:
> 
> rndc managed-keys refresh
> rndc managed-keys sync
> 
> But don't understand why that would have been necessary unless the root keys got updated recently.
> 
> Scrolling to the very top of the logs I see:
> 
> May 12 19:24:04 OpenWrt named[11061]: managed-keys-zone: Unable to fetch DNSKEY set '.': timed out
> 
> Thanks,
> 
> -Philip
> 
> 
> -- 
> Visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list
> 
> ISC funds the development of this software with paid support subscriptions. Contact us at https://www.isc.org/contact/ for more information.
> 
> 
> bind-users mailing list
> bind-users at lists.isc.org
> https://lists.isc.org/mailman/listinfo/bind-users