resolv.conf and DNS configration

UNIX AIX
1

Guys,

I have enabled the resolv.conf to be configured with our DNS Network

and it's configured when I ping any hostname in my Network from the server it's giving me the hostname of that machine (witch mean it's working fine )

but I�m facing slowness in my connection when I rename the resolv.conf to another name it's work fain when I return the original name of resolv.conf slowness came again .

Pls advice in this...

2

You mean that you are changing contents of resolv.conf file?? if so please provide content of the file

3

If I understand you correctly it works fine with the resolv.conf file in place but it's just slow (actually what is slow)...So after the rename of the resolv.conf file things speed up again. I would suggest looking at the netsvc.conf and see how it is configured and what values due you have in the resolv.conf file?

4

To be honest i do not know exactly what you are doing and what you want to achieve. Please restate your requirements if the (generic) explanation below is not covering your needs.

To enable the name resolution via DNS the system has to be told where to ask - i.e. what the IP address of the name server is. This information is stored in /etc/resolv.conf.

If you execute, for instance, a "ping remote.host.com" the following happens:

  1. your host notices that "remote.host.com" is no IP-address and attempts to resolve it.
  2. your host looks up /etc/netsvc.conf to find out which method(s) of name resolution (DNS, NIS, /etc/hosts) it should use and in which order of precedence
  3. in case of DNS your host sends a request to the DNS server identified in /etc/resolv.conf and waits until it answers or the timeout value is reached
  4. the DNS server answers with an IP-address (for a name) or a name (for an IP address)
  5. your host issues "ping IP-address" with the IP-address provided by your name resolution method.

If now the name resolution is significantly slower with DNS than it is otherwise (maybe a local /etc/hosts with the same information?) probably the answer from your name server arrives late - maybe because of network congestion, maybe because the name server is under load, maybe something else.

To investigate possible causes for such a problem you can do nothing else than carefully testing and approving/disproving the various possible reasons.

I hope this helps.

bakunin

5

Please provide me the resolv.conf file settings, let me compeer it with my exist file

6

seems like a DNS issue

here is a sample resolv.conf from one of my machines:

nameserver      x.x.x.x
nameserver      x.x.x.x
nameserver      x.x.x.x
domain sub.domain.at
search sub.domain.at sub.domain.1.at sub.domain.2.at
options         attempts:1
options         timeout:1

as you can see, I'm using 3 nameservers

7

I dont have in my resolv.conf file included these options options attempts:1
options timeout:1
could you try to remove them?

8

Thank you funksen

anothere thing if you can..

Is there a related connection relationship between resolv.conf and .netrc

as I'm trying to connect from my machine by ftp to another machine by using .netrc login details but the connation is very slow and some time is going and some time is failed ...

9

What is the contents of /etc/nsswitch.conf ?

10

why should I ? :slight_smile:

11

thanx it's work fain with me

I defain it like this

nameserver xxx.xxx.xxx.xxx
nameserver xxx.xxx.xxx.xxx
search my.domain
options attempts:0
options timeout:0

12

don't know what 0 exactly does, but 0 attempts would explain the performance improvement, it's just not asking the dns-server *gg*

13

My mistake. Not called /etc/nsswitch.conf in AIX.

What is the contents of /etc/netsvc.conf ?

14

nevermind.