Retry and Retrans in resolv.conf

[Phil2 Davey]

There are intermittent issues with our 3 DNS actrive directory servers that means that occasionally one or another of them may not be visible to the estate. This is causing issues with a customer application that cannot cope with delays in name resolution.

To test things out, I have put a non_DNS server at the top of the nameserver list in resolv.conf, then run nslookup under "time" and get a 75 second response. "time nslookup "
This is consistent with a retrans = 5000 and retry = 4 (which I believe are the default values).

I have tried adding entries for retrans and retry to resolv.conf to reduce this, and also tried setting environment variables RES_RETRY and RES_RETRANS, but neither of these options seems to override the default settings.

The only way I seem to be able to reduce the timeout is to run nslookup with the retry option, which would not really help the application.

Any suggestions would be appreciated.

TIA

[Rita C Workman]

If your application is running on a UNIX box then you can speed things up by having it resolve first via "files" then "dns" in your /etc/nsswitch.conf.

If your problem is strictly DNS Active Dire ctory on Windows, then you might try also posting this on the Windows group.

Rgrds,
Rita

[Geoff Wild]

Add the following to bottom of resolv.conf:


retrans 2500
retry 2


Rgds...Geoff

[Phil2 Davey]

The issue I am addressing is not with the Active Directory, but the name resolution on the server. We may end up putting entries in the hosts file to resolve it, but that is not an ideal solution.

Putting retrans and retry at the end of resolv.conf had the same effect as when I had put them at the beginning, I.e. None.

Thanks for the suggestions, but I still need to reduce the timeout for looking up DNS.

[TTr]

You did not mention the HP-UX version but if it is 11.00, the two options were added with a patch, they were not available from the begining.

[Mel Burslan]

Just a hunch: How does your nsswitch.conf file look ? Do you have a [... UNAVAIL=continue ...] after your DNS entry, "..." referring to other entries ?

[Phil2 Davey]

OS Vers.
11.11 on PA-Risc

I have tried the following nsswitch.conf entries:
hosts: files dns
hosts: files dns [UNAVAIL=continue]
hosts: dns files
hosts: dns [UNAVAIL=continue] files

Thanks for the suggestions