topic Re: Initial connection slow since adding dns in Operating System - HP-UX

Initial connection slow since adding dns

George_Dodds — Thu, 02 Sep 2004 06:01:54 GMT

I'm running HPUX11iv1 on a quad proc L2000 6gb ram and a gigabit lan card.

I've recently had to add one of my servers to a domain and start using the company dns servers.

I've noticed that when i connection to the ip addess of my server the initial connection seems slower.

Other people have complained of timeouts when connecting to the ip as well.

The Network is fine, no errors on nic or on the switch.

This just seems to have happened since i started using dns, but if i'm connecting to the ip address why should that make a difference?

Ta

George

Re: Initial connection slow since adding dns

Pete Randall — Thu, 02 Sep 2004 06:06:02 GMT

George,

How is your /etc/nsswitch.conf set up? It should be:

hosts: files[NOTFOUND=continue UNAVAIL=continue] dns [NOTFOUND=continue UNAVAIL=continue TRYAGAIN=return] nis

Pete

Re: Initial connection slow since adding dns

George_Dodds — Thu, 02 Sep 2004 06:07:51 GMT

/etc/nsswitch.conf entry

hosts: files [NOTFOUND=continue] dns

Re: Initial connection slow since adding dns

Muthukumar_5 — Thu, 02 Sep 2004 06:23:19 GMT

what is your hosts: entry on /etc/nsswitch.conf

Based upon the setting only it is getting resolved.
You can verify them with nslookup and nsquery commands

Some discussion here to calculate timings as,
http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=684203

We will meet after your hosts: entry on nsswitch.conf file

Re: Initial connection slow since adding dns

RAC_1 — Thu, 02 Sep 2004 06:25:23 GMT

How does the /etc/resolv.conf looks like??
Is the response Ok, if you try connecting to ip_address instead of hostname???

You may want to have a look at the man page of resolver. You may also add retrans and retry options to resolv.conf.

The /etc/nsswitch.conf looks OK.
Anything on DNS server to denote that the address resolution for your server's ip address is taking time??

Anil

Re: Initial connection slow since adding dns

George_Dodds — Thu, 02 Sep 2004 06:40:09 GMT

see above for hosts: entry in nsswitch.conf

nslookup if fine, it is just the initial connection to the server itself is slow

Re: Initial connection slow since adding dns

Steve Lewis — Thu, 02 Sep 2004 07:17:33 GMT

If the users telnet to your server, then the server will attempt a name lookup for the client's IP before giving them a prompt.

This is a common cause of slow logins.

If you do a who -u then nsquery hosts [some-IP] you will be able to time how long it takes, as long as verifying the lookup method.

The fact that the users may connect to the server's IP and not the name makes no difference.

Re: Initial connection slow since adding dns

Muthukumar_5 — Thu, 02 Sep 2004 08:33:20 GMT

The entry of

hosts: files [NOTFOUND=continue] dns

say's

If resolvation of host is not in files then continue to dns

Why can you use as,

hosts: files dns

And more,
IS your hostname of login on /etc/hosts or in dns server.

If it is on dns then use as,

hosts: dns files

And try to check resolvation of entry now as,

nsquery hosts hostname "dns"

IS it resolving on first nameserver / next or third one?

But "Initial connection slow since adding dns" makes only first time connection.

May be login service time problem too..

Re: Initial connection slow since adding dns

Geoff Wild — Thu, 02 Sep 2004 09:07:20 GMT

One thing to check, is the FQDN set in /etc/hosts?

Rgds...Geoff

Re: Initial connection slow since adding dns

George_Dodds — Thu, 02 Sep 2004 09:41:05 GMT

Yup FQDN is in hosts :)

Re: Initial connection slow since adding dns

harry d brown jr — Thu, 02 Sep 2004 09:50:01 GMT

Can you post your /etc/resolv.conf file?

This gives rules to DNS on how to behave. I bet if you looked at your DNS servers that they are trying to resolve names to the internet root servers before they append your domain name to the pc/ws name, which is why it's important to have a correctly configured resolv.conf file.

Also, what version of bind are you running?
run: what /usr/sbin/named
run: ps -ef | grep named
Do you have a file called /etc/named.conf?

live free or die
harry

Re: Initial connection slow since adding dns

George_Dodds — Thu, 02 Sep 2004 10:09:18 GMT

more /etc/resolv.conf
search unix.eu.primus eu.primus
nameserver *.*.29.39
nameserver *.*.29.38
nameserver *.*.29.37
nameserver *.*.100.10

named 8.1.2

root 13318 2047 1 16:04:24 pts/td 0:00 grep named

There is no named.conf

Just realised sendmail is whinging about the mail relay server -host unknown

Arrgh!