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Firefox launcher is blocked in slow DNS queries for local hostname

  • 3 replies
  • 1 has this problem
  • 1 view
  • Last reply by mzabaluev

mzabaluev
mzabaluev
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I have got a dual-stack network interface configuration from one of Wi-Fi routers that provides the Linux PC with one IPv4 address and two IPv6 addresses. When this interface is connected, the Firefox launcher executable takes about 10 seconds to open a new window, even if the Firefox browser process is already running (and will be the process to open the window upon receiving an IPC from the launcher). IP packet capture and strace logs show that the launcher waits 5 seconds on two successive DNS queries trying to resolve A and AAAA records for the local hostname (as retrieved by e.g. "hostname" command). The hostname is not a FQDN, is locally assigned, does not match any DNS records and is not written into /etc/hosts; the DHCP configuration does not assign any domain name to the host either.

The IP addresses are assigned as follows: 

       inet 192.168.8.108  netmask 255.255.255.0  broadcast 192.168.8.255
       inet6 2001:999:50:fa22:6462:1479:f78:e78d  prefixlen 64  scopeid 0x0<global>
       inet6 2001:999:50:fa22:446e:e539:5727:6  prefixlen 128  scopeid 0x0<global>
       inet6 fe80::b425:e062:cddc:2aa4  prefixlen 64  scopeid 0x20<link>

/etc/resolv.conf is automatically generated as follows:

  1. Generated by NetworkManager

nameserver 192.168.8.1 nameserver fe80::466e:e5ff:fe39:5727%wlp3s0

There are some old bugs in Bugzilla (https://bugzilla.mozilla.org/show_bug.cgi?id=433665) making me suspect that it might be some fallback code that kicks in when multiple IP addresses are available for the local host. Is there a way to fix this behavior without hardcoding the IP addresses into system configuration files?

I have got a dual-stack network interface configuration from one of Wi-Fi routers that provides the Linux PC with one IPv4 address and two IPv6 addresses. When this interface is connected, the Firefox launcher executable takes about 10 seconds to open a new window, even if the Firefox browser process is already running (and will be the process to open the window upon receiving an IPC from the launcher). IP packet capture and strace logs show that the launcher waits 5 seconds on two successive DNS queries trying to resolve A and AAAA records for the local hostname (as retrieved by e.g. "hostname" command). The hostname is not a FQDN, is locally assigned, does not match any DNS records and is not written into /etc/hosts; the DHCP configuration does not assign any domain name to the host either. The IP addresses are assigned as follows: inet 192.168.8.108 netmask 255.255.255.0 broadcast 192.168.8.255 inet6 2001:999:50:fa22:6462:1479:f78:e78d prefixlen 64 scopeid 0x0<global> inet6 2001:999:50:fa22:446e:e539:5727:6 prefixlen 128 scopeid 0x0<global> inet6 fe80::b425:e062:cddc:2aa4 prefixlen 64 scopeid 0x20<link> /etc/resolv.conf is automatically generated as follows: # Generated by NetworkManager nameserver 192.168.8.1 nameserver fe80::466e:e5ff:fe39:5727%wlp3s0 There are some old bugs in Bugzilla (https://bugzilla.mozilla.org/show_bug.cgi?id=433665) making me suspect that it might be some fallback code that kicks in when multiple IP addresses are available for the local host. Is there a way to fix this behavior without hardcoding the IP addresses into system configuration files?

All Replies (3)

Shadow110
Shadow110
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Sorry, that is beyond me. Possibly everyone as no one has answered you.

cor-el
cor-el
  • Moderator
  • Top 10 Contributor
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Try to ask advice at the Stack Overflow forum site.

There is a network.dns.localDomains pref available on the about:config page.

mzabaluev
mzabaluev Question owner
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I have filed a bug on Bugzilla. I think the launcher behavior is wrong: it should not block on network queries in order to open a window, neither tweaking an obscure configuration preference is a good solution.