Thank you for a detailed and competent answer. This clarifies the issue. Now it makes sense why this cannot and should not be fixed in Ubuntu.
To summarize: If you experience lookup delays, change your /etc/nsswitch.conf to this: $ cat /etc/nsswitch.conf # /etc/nsswitch.conf # # Example configuration of GNU Name Service Switch functionality. # If you have the `glibc-doc-reference' and `info' packages installed, try: # `info libc "Name Service Switch"' for information about this file. passwd: compat group: compat shadow: compat # https://bugs.launchpad.net/ubuntu/+source/nss-mdns/+bug/94940 # Original, delayed lookup on improperly configured internal networks: #hosts: files mdns4_minimal [NOTFOUND=return] dns # Use this if you're not on a local network with Microsoft services or if you don't need on them: #hosts: files dns # Delays looking up hosts on your internal network, but you *will* get the best of both worlds; # multicast DNS resolution *and* resolution of your incorrectly-named internal network: hosts: files mdns4_minimal dns networks: files protocols: db files services: db files ethers: db files rpc: db files netgroup: nis -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to avahi in Ubuntu. https://bugs.launchpad.net/bugs/94940 Title: mdns listed in nsswitch.conf causes excessive time for dns lookups Status in avahi package in Ubuntu: Confirmed Status in nss-mdns package in Ubuntu: Confirmed Status in nss-mdns package in Debian: Fix Released Bug description: Binary package hint: avahi-daemon I encountered this problem on a machine that is integrated into our work network. I performed a dist-upgrade to Feisty on my desktop and all went well. I've noticed recently that any dns based work seemed to take a significantly longer time then normal. My system is getting dns information on our company internal systems from two dns servers. Previously, if I tried to establish an ssh connection with another system I could generally expect the connection in under 3 secs. After the dist-upgrade the time went from under 3 seconds to approximately 25 seconds. After searching around the system I found an entry in /etc/nsswitch.conf that cause me a little concern. The line in question is: hosts: files mdns4_minimal [NOTFOUND=return] dns mdns4 I looked around a bit and it seems that the references to mdns are really talking about communication with the Avahi mDNS/DNS-SD daemon. Since this looks to be a part of a zeroconf configuration I wasn't expecting too much in my current environment, as we really only have three Mac's. What concerned me is the idea that if we hit files with no answer there is a delay while we hit the other options until we hit dns, which is where the information I seek existed. For an experiment I tried two separate tests. The first changed the line to looks like: hosts: files dns mdns4_minimal [NOTFOUND=return] mdns The change should have improved the time, but I was still looking at approximately 23 seconds to return a command prompt on the destination machine. Finally, I change the entry to simply: hosts: files dns After this change I was again receiving the destination command prompt in under 3 seconds. I don't know if simply changing the file will correct the problem long-term or not. Seems to help me, but might be the way to go for most Ubuntu users. ProblemType: Bug Architecture: i386 Date: Thu Mar 22 18:10:54 2007 DistroRelease: Ubuntu 7.04 Uname: Linux samdesk 2.6.20-12-generic #2 SMP Wed Mar 21 20:55:46 UTC 2007 i686 GNU/Linux To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/avahi/+bug/94940/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : [email protected] Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
