Re: [Dnsmasq-discuss] Still investigating delay on first dns query - more info
On Thu, Mar 26, 2020 at 12:02:45PM +, Simon Kelley wrote: > On 23/03/2020 13:25, Chris Green wrote: > > > > I'm running dnsmasq version 2.76 on a Raspberry Pi. The systems > > seeing the delay when they send a query are (mostly) running xubuntu > > 19.10. > > > > The delay only occurs when querying names on the LAN, requests for > > external names run normally. It makes no difference whether I give a fully > > qualified name or just the machine name (the domain gets added by the > > 'search' option in /etc/resolv.con anyway). > > > > It appears to be something to do with IPV6 and records (or lack > > of them) that causes the issue but I'm still stumped as to how to fix > > it. > > > > Having set 'log-queries=extra' in /etc/dnsmasq.conf I see the > > following in /var/log/syslog when I query (using 'host') the name > > 'esprimo' twice from my laptop after booting (booting the laptop that > > is). > > [snip log] > > > > So for some reason first time round the querying system asks > > repeatedly for the record, then waits 5 seconds, asks again and > > then gives up. But it only does this the first time it sends the > > query. (I suspect that the delay re-occurs after a long idle time but > > I can't reproduce the delay by clearing the systemd resolvctl cache) > > > > I realise this probably isn't directly a dnsmasq problem but I'd > > really appreciate any suggestions or workarounds that might help me > > fix this issue. I can easily add more debug flags or configuration if > > they might help. > > > > > Dnsmasq looks to be doing the right thing here, if one assumes that what > it sends is the same as what it logs (and I have not reason to believe > it isn't). > > Given the MX query, it looks like the originator may be a mail transfer > agent (sendmail, exim and friends). Can you determine what is making the > queries and maybe configure it not to use IPv6? > > Yes, thank you Simon. It just dawned on me (thinking about it in bed last night) that the log only shows what dnsmasq *sent* and not what was received or acted on at the other end. I think my next job is probably to set up wireshark or something like it and actually observer what is going in and out of the client system. -- Chris Green ___ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
Re: [Dnsmasq-discuss] Still investigating delay on first dns query - more info
On 23/03/2020 13:25, Chris Green wrote: > I'm still trying to work out why the first DNS query to dnsmasq > running on a server on my LAN suffers a 5 second delay but subsequent > requests don't see the delay. > > I'm running dnsmasq version 2.76 on a Raspberry Pi. The systems > seeing the delay when they send a query are (mostly) running xubuntu > 19.10. > > The delay only occurs when querying names on the LAN, requests for > external names run normally. It makes no difference whether I give a fully > qualified name or just the machine name (the domain gets added by the > 'search' option in /etc/resolv.con anyway). > > It appears to be something to do with IPV6 and records (or lack > of them) that causes the issue but I'm still stumped as to how to fix > it. > > Having set 'log-queries=extra' in /etc/dnsmasq.conf I see the > following in /var/log/syslog when I query (using 'host') the name > 'esprimo' twice from my laptop after booting (booting the laptop that > is). > > First 'host esprimo':- > Mar 23 12:59:06 newdns dnsmasq[4256]: 54 192.168.1.92/56886 query[A] > esprimo.zbmc.eu from 192.168.1.92 > Mar 23 12:59:06 newdns dnsmasq[4256]: 54 192.168.1.92/56886 /etc/hosts > esprimo.zbmc.eu is 192.168.1.3 > Mar 23 12:59:06 newdns dnsmasq[4256]: 55 192.168.1.92/37906 query[] > esprimo.zbmc.eu from 192.168.1.92 > Mar 23 12:59:06 newdns dnsmasq[4256]: 55 192.168.1.92/37906 config > esprimo.zbmc.eu is NODATA-IPv6 > Mar 23 12:59:06 newdns dnsmasq[4256]: 56 192.168.1.92/37906 query[] > esprimo.zbmc.eu from 192.168.1.92 > Mar 23 12:59:06 newdns dnsmasq[4256]: 56 192.168.1.92/37906 config > esprimo.zbmc.eu is NODATA-IPv6 > Mar 23 12:59:06 newdns dnsmasq[4256]: 57 192.168.1.92/37906 query[] > esprimo.zbmc.eu from 192.168.1.92 > Mar 23 12:59:06 newdns dnsmasq[4256]: 57 192.168.1.92/37906 config > esprimo.zbmc.eu is NODATA-IPv6 > Mar 23 12:59:06 newdns dnsmasq[4256]: 58 192.168.1.92/37906 query[] > esprimo.zbmc.eu from 192.168.1.92 > Mar 23 12:59:06 newdns dnsmasq[4256]: 58 192.168.1.92/37906 config > esprimo.zbmc.eu is NODATA-IPv6 > Mar 23 12:59:06 newdns dnsmasq[4256]: 59 192.168.1.92/37906 query[] > esprimo.zbmc.eu from 192.168.1.92 > Mar 23 12:59:06 newdns dnsmasq[4256]: 59 192.168.1.92/37906 config > esprimo.zbmc.eu is NODATA-IPv6 > Mar 23 12:59:06 newdns dnsmasq[4256]: 60 192.168.1.92/37906 query[] > esprimo.zbmc.eu from 192.168.1.92 > Mar 23 12:59:06 newdns dnsmasq[4256]: 60 192.168.1.92/37906 config > esprimo.zbmc.eu is NODATA-IPv6 > Mar 23 12:59:06 newdns dnsmasq[4256]: 61 192.168.1.92/37906 query[] > esprimo.zbmc.eu from 192.168.1.92 > Mar 23 12:59:06 newdns dnsmasq[4256]: 61 192.168.1.92/37906 config > esprimo.zbmc.eu is NODATA-IPv6 > Mar 23 12:59:06 newdns dnsmasq[4256]: 62 192.168.1.92/37906 query[] > esprimo.zbmc.eu from 192.168.1.92 > Mar 23 12:59:06 newdns dnsmasq[4256]: 62 192.168.1.92/37906 config > esprimo.zbmc.eu is NODATA-IPv6 > Mar 23 12:59:06 newdns dnsmasq[4256]: 63 192.168.1.92/37906 query[] > esprimo.zbmc.eu from 192.168.1.92 > Mar 23 12:59:06 newdns dnsmasq[4256]: 63 192.168.1.92/37906 config > esprimo.zbmc.eu is NODATA-IPv6 > Mar 23 12:59:06 newdns dnsmasq[4256]: 64 192.168.1.92/37906 query[] > esprimo.zbmc.eu from 192.168.1.92 > Mar 23 12:59:06 newdns dnsmasq[4256]: 64 192.168.1.92/37906 config > esprimo.zbmc.eu is NODATA-IPv6 > Mar 23 12:59:06 newdns dnsmasq[4256]: 65 192.168.1.92/37906 query[] > esprimo.zbmc.eu from 192.168.1.92 > Mar 23 12:59:06 newdns dnsmasq[4256]: 65 192.168.1.92/37906 config > esprimo.zbmc.eu is NODATA-IPv6 > Mar 23 12:59:06 newdns dnsmasq[4256]: 66 192.168.1.92/37906 query[] > esprimo.zbmc.eu from 192.168.1.92 > Mar 23 12:59:06 newdns dnsmasq[4256]: 66 192.168.1.92/37906 config > esprimo.zbmc.eu is NODATA-IPv6 > Mar 23 12:59:06 newdns dnsmasq[4256]: 67 192.168.1.92/37906 query[] > esprimo.zbmc.eu from 192.168.1.92 > Mar 23 12:59:06 newdns dnsmasq[4256]: 67 192.168.1.92/37906 config > esprimo.zbmc.eu is NODATA-IPv6 > Mar 23 12:59:06 newdns dnsmasq[4256]: 68 192.168.1.92/37906 query[] > esprimo.zbmc.eu from 192.168.1.92 > Mar 23 12:59:06 newdns dnsmasq[4256]: 68 192.168.1.92/37906 config > esprimo.zbmc.eu is NODATA-IPv6 > Mar 23 12:59:06 newdns dnsmasq[4256]: 69 192.168.1.92/37906 query[] > esprimo.zbmc.eu from 192.168.1.92 > Mar 23 12:59:06 newdns dnsmasq[4256]: 69 192.168.1.92/37906 config > esprimo.zbmc.eu is NODATA-IPv6 > Mar 23 12:59:06 newdns dnsmasq[4256]: 70 192.168.1.92/37906 query[] > esprimo.zbmc.eu from 192.168.1.92 > Mar 23 12:59:06 newdns dnsmasq[4256]: 70 192.168.1.92/37906 config > esprimo.zbmc.eu is NODATA-IPv6 > Mar 23 12:59:06 newdns dnsmasq[4256]: 71 192.168.1.92/37906 query[] > esprimo.zbmc.eu from 192.168.1.92 > Mar 23 12:59:06 newdns dnsmasq[4256]: 71 192.168.1.92/37906 config > esprimo
[Dnsmasq-discuss] Still investigating delay on first dns query - more info
I'm still trying to work out why the first DNS query to dnsmasq running on a server on my LAN suffers a 5 second delay but subsequent requests don't see the delay. I'm running dnsmasq version 2.76 on a Raspberry Pi. The systems seeing the delay when they send a query are (mostly) running xubuntu 19.10. The delay only occurs when querying names on the LAN, requests for external names run normally. It makes no difference whether I give a fully qualified name or just the machine name (the domain gets added by the 'search' option in /etc/resolv.con anyway). It appears to be something to do with IPV6 and records (or lack of them) that causes the issue but I'm still stumped as to how to fix it. Having set 'log-queries=extra' in /etc/dnsmasq.conf I see the following in /var/log/syslog when I query (using 'host') the name 'esprimo' twice from my laptop after booting (booting the laptop that is). First 'host esprimo':- Mar 23 12:59:06 newdns dnsmasq[4256]: 54 192.168.1.92/56886 query[A] esprimo.zbmc.eu from 192.168.1.92 Mar 23 12:59:06 newdns dnsmasq[4256]: 54 192.168.1.92/56886 /etc/hosts esprimo.zbmc.eu is 192.168.1.3 Mar 23 12:59:06 newdns dnsmasq[4256]: 55 192.168.1.92/37906 query[] esprimo.zbmc.eu from 192.168.1.92 Mar 23 12:59:06 newdns dnsmasq[4256]: 55 192.168.1.92/37906 config esprimo.zbmc.eu is NODATA-IPv6 Mar 23 12:59:06 newdns dnsmasq[4256]: 56 192.168.1.92/37906 query[] esprimo.zbmc.eu from 192.168.1.92 Mar 23 12:59:06 newdns dnsmasq[4256]: 56 192.168.1.92/37906 config esprimo.zbmc.eu is NODATA-IPv6 Mar 23 12:59:06 newdns dnsmasq[4256]: 57 192.168.1.92/37906 query[] esprimo.zbmc.eu from 192.168.1.92 Mar 23 12:59:06 newdns dnsmasq[4256]: 57 192.168.1.92/37906 config esprimo.zbmc.eu is NODATA-IPv6 Mar 23 12:59:06 newdns dnsmasq[4256]: 58 192.168.1.92/37906 query[] esprimo.zbmc.eu from 192.168.1.92 Mar 23 12:59:06 newdns dnsmasq[4256]: 58 192.168.1.92/37906 config esprimo.zbmc.eu is NODATA-IPv6 Mar 23 12:59:06 newdns dnsmasq[4256]: 59 192.168.1.92/37906 query[] esprimo.zbmc.eu from 192.168.1.92 Mar 23 12:59:06 newdns dnsmasq[4256]: 59 192.168.1.92/37906 config esprimo.zbmc.eu is NODATA-IPv6 Mar 23 12:59:06 newdns dnsmasq[4256]: 60 192.168.1.92/37906 query[] esprimo.zbmc.eu from 192.168.1.92 Mar 23 12:59:06 newdns dnsmasq[4256]: 60 192.168.1.92/37906 config esprimo.zbmc.eu is NODATA-IPv6 Mar 23 12:59:06 newdns dnsmasq[4256]: 61 192.168.1.92/37906 query[] esprimo.zbmc.eu from 192.168.1.92 Mar 23 12:59:06 newdns dnsmasq[4256]: 61 192.168.1.92/37906 config esprimo.zbmc.eu is NODATA-IPv6 Mar 23 12:59:06 newdns dnsmasq[4256]: 62 192.168.1.92/37906 query[] esprimo.zbmc.eu from 192.168.1.92 Mar 23 12:59:06 newdns dnsmasq[4256]: 62 192.168.1.92/37906 config esprimo.zbmc.eu is NODATA-IPv6 Mar 23 12:59:06 newdns dnsmasq[4256]: 63 192.168.1.92/37906 query[] esprimo.zbmc.eu from 192.168.1.92 Mar 23 12:59:06 newdns dnsmasq[4256]: 63 192.168.1.92/37906 config esprimo.zbmc.eu is NODATA-IPv6 Mar 23 12:59:06 newdns dnsmasq[4256]: 64 192.168.1.92/37906 query[] esprimo.zbmc.eu from 192.168.1.92 Mar 23 12:59:06 newdns dnsmasq[4256]: 64 192.168.1.92/37906 config esprimo.zbmc.eu is NODATA-IPv6 Mar 23 12:59:06 newdns dnsmasq[4256]: 65 192.168.1.92/37906 query[] esprimo.zbmc.eu from 192.168.1.92 Mar 23 12:59:06 newdns dnsmasq[4256]: 65 192.168.1.92/37906 config esprimo.zbmc.eu is NODATA-IPv6 Mar 23 12:59:06 newdns dnsmasq[4256]: 66 192.168.1.92/37906 query[] esprimo.zbmc.eu from 192.168.1.92 Mar 23 12:59:06 newdns dnsmasq[4256]: 66 192.168.1.92/37906 config esprimo.zbmc.eu is NODATA-IPv6 Mar 23 12:59:06 newdns dnsmasq[4256]: 67 192.168.1.92/37906 query[] esprimo.zbmc.eu from 192.168.1.92 Mar 23 12:59:06 newdns dnsmasq[4256]: 67 192.168.1.92/37906 config esprimo.zbmc.eu is NODATA-IPv6 Mar 23 12:59:06 newdns dnsmasq[4256]: 68 192.168.1.92/37906 query[] esprimo.zbmc.eu from 192.168.1.92 Mar 23 12:59:06 newdns dnsmasq[4256]: 68 192.168.1.92/37906 config esprimo.zbmc.eu is NODATA-IPv6 Mar 23 12:59:06 newdns dnsmasq[4256]: 69 192.168.1.92/37906 query[] esprimo.zbmc.eu from 192.168.1.92 Mar 23 12:59:06 newdns dnsmasq[4256]: 69 192.168.1.92/37906 config esprimo.zbmc.eu is NODATA-IPv6 Mar 23 12:59:06 newdns dnsmasq[4256]: 70 192.168.1.92/37906 query[] esprimo.zbmc.eu from 192.168.1.92 Mar 23 12:59:06 newdns dnsmasq[4256]: 70 192.168.1.92/37906 config esprimo.zbmc.eu is NODATA-IPv6 Mar 23 12:59:06 newdns dnsmasq[4256]: 71 192.168.1.92/37906 query[] esprimo.zbmc.eu from 192.168.1.92 Mar 23 12:59:06 newdns dnsmasq[4256]: 71 192.168.1.92/37906 config esprimo.zbmc.eu is NODATA-IPv6 Mar 23 12:59:06 newdns dnsmasq[4256]: 72 192.168.1.92/37906 query[] esprimo.zbmc.eu from 192.168.1.92 Mar 23 12:59:06 newdns dnsmasq[4256]: 72 192.168.1.92/37906 config esprimo.zbmc.eu is NODA
