Slow telnet and ftp login response 2

[mrberry]

I have 3 AIX servers, 2 of which exhibit this problem and 1 does not.

On the 2 problem hosts when I telnet or ftp from a PC running XP it just sits there for about 60 seconds. On a telnet I eventually get a prompt and can login. With ftp I get the connected to host message, but never get a login prompt - just a "connection closed by remote host" message after about 60 seconds.

This problem does not occur when I telnet or ftp between the AIX hosts.

I seem to remeber that you have to set the duplex setting in the network interface to resolve such a problem, but could be wrong. I can't find where to set this anyway.

Does anyone know a solution to this problem?

Thanks

Mark

 

[mrberry]

Sorry, I meant to post this in the AIX forum.

 

[grega]

Check that DNS is confirgured correctly on the 2 slow boxes.

Greg.

 

[dblair]

Networking rather than a Unix issue if your FTP/Telent between the boxes is fine.

 

[mrberry]

grega, this was indeed a DNS issue. It appears that that the nameserver is not resolving names of PCs that have IP addresses set by DHCP.

When ftp or telnet is run it hangs because it appears to be attempting to do a reverse lookup. If I remove the resolv.conf I don't get the problem.

Thanks,

Mark

 

[Credit123]

Hi mrberry,

I am having a similar problem with my server. When I telnet by IP Address, it takes 1 minutes and 22 seconds for me to get a login prompt and ftp gives the message "connection closed by remote host". The IP addresses for all of our client machines were assigned by our DHCP server. I noticed that when you deleted the resolv.conf file you stopped having the problem. We are running a Unixware 7.1.0 Operating system on a Compaq Proliant 3000 Server. I noticed however that there are two resolv.conf files:

1) resolv.conf
2) resolv.conf-

What is the resolv.conf file, how important it is and if there are any side effects of removing both files.

Thanks in Advance,

Tuan

 

[PHV]

The resolv.conf- file is a backup, so no need to delete it.
Simply do something like this:
mv /etc/resolv.conf /etc/resolv.conf.save

Hope This Helps, PH.
Want to get great answers to your Tek-Tips questions? Have a look at FAQ219-2884 or FAQ222-2244

 

[mrberry]

Tuan, the resolv.conf file on an AIX system (I have no experience with Unixware) is used for pointing the machine towards your DNS name server(s) - that is the host(s) that can resovle host names to IP addresses.

If this file is not present or empty the only hostnames it will be able to resolve are those found locally in your /etc/hosts file. You will still be able to contact remote hosts using IP address, but not by name if this file is not present.

My *guess* is the second file thay you see resolv.conf- on your Unixware system is a an old backup file, perhaps created by an editor?

 

[mrberry]

Tuan, as an adendum: you have to be careful when making *any* system change as it may have knock on affects that you don't realise at the time.

I thought that I didn't need the resolv.conf but the next day I never received my backup reports via email. The email server was not longer able to be resolve the email host's name.

This was easily fixed by adding it to /etc/hosts but illustrates how making a change can cause unforseen problems.