telnet delay issue with dns

Amir Haboosheh — Mon, 28 Sep 2009 23:32:14 GMT

HPUX 11.23

resolv.conf:
domain mydomain
nameserver 10.0.20.16
retrans:1000
retry:1

nsswitch.conf:
hosts: files [NOTFOUND=continue TRYAGAIN=continue UNAVAIL=continue] dns
ipnodes: files [NOTFOUND=continue TRYAGAIN=continue UNAVAIL=continue] dns

i searched the forums and read 30+ threads regarding this issue and don't understand it.
i want my telnet prompt to be independent of a dns reverse lookup. i understand that its a "security" issue where before hpux send a prompt it does a reverse lookup of the source ip but if my dns server goes down we don't get a login and that’s a problem. besides how is it that if i remove the resolv.conf file i get the login right away? why can't i have it behave like that regardless of the dns servers availability?

i even tried adding a pc's name to the host file and then shutdown the dns server, but the prompt still delays.

any help would be appreciated.

thanks,
amir

Re: telnet delay issue with dns

Bill Hassell — Tue, 29 Sep 2009 01:06:18 GMT

> i want my telnet prompt to be independent of a dns reverse lookup.

That is hard coded into telnet and not configurable.

> how is it that if i remove the resolv.conf file i get the login right away?

That condition defines that DNS is not available and won't be consulted.

> i even tried adding a pc's name to the host file and then shutdown the dns server, but the prompt still delays.

Rather than shutdown the DNS server, just put some other IP address in resolv.conf (that is not a DNS server). However, giving the IP address of your PC a name in /etc/hosts should resolve before DNS. Use nsquery to see how the name and IP are resolved:

nsquery hosts 12.34.56.78
nsquery hosts mypcname

Note that you can also add another nsswitch.conf ruleset to nsquery:

nsquery hosts mypcname "dns [NOTFOUND=continue TRYAGAIN=return] files"

topic telnet delay issue with dns in Operating System - HP-UX

telnet delay issue with dns

Re: telnet delay issue with dns