Slow netstat, telnet, and ftp to Unixware 7.1.0 Server 3

[Credit123]

Hi forks,

When I telnet to the server it takes 1 minutes and 22 seconds to get the login prompt. I experience the same problem with ftp. When I do a netstat -i on the server it takes just about the same time for me to get a response. I noticed however that when i do netstat -I and the inferface for the server(net0") I get a quick response, while if I do a netstat -I on the localhost interface i get slow response. What could be causing this problem. The problem start after I restart the server one evening, but no changes were made that day.

Spec:
OS: Unixware 7.1.0
On a Compaq proliant 3000 Server
with a maximum of 50 users.

Credit123

 

[PHV]

How long takes a telnet to the server IP address ?
If far less time than telnet to the server name, then consider to review your DNS config.

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

 

[stanhubble]

it could still be a dns problem if it takes as long using the ip address. a lot of the time the problem is the unix system begin delayed while doing a reverse arp lookup on your client. it is the resolution of your (or all of) the clients ip -> name lookup.

 

[PHV]

Good catch stanhubble, I've forgotten the reverse lookup thing.

 

[Credit123]

Hi PHV, stanhubble,

Thank you for your quick response. It takes 1 minutes and 22 seconds to give a login prompt when we tried to telnet by IP Address. I am not too famaliar with reverse arp lookup so, I am doing some research now.

Thanks,

Credit123

 

[Credit123]

Hi PHV, stanhubble,

We have checked to ensure that DNS settings (i.e. Nameserver search order, Domain search order and local domain are correct) are correct. What could be causing the localhost to respond so slowly?

Stanhubble in your post, you mentioned that the problem could be the unix system is being delayed while doing a reverse arp lookup on the client IP addresses. What solutions do you suggest to this problem?

Thanks in Advance,

Credit123

 

[stanhubble]

1 - ping localhost
2 - ping your_dns_by_ip
3 - ping your_dns_by_name
4 - ping your_host_by_ip
5 - ping your_host_by_name
6 - ping your_client_by_ip
7 - ping your_client_by_name

see if any of these take too long to start.

does localhost exist in your hosts file?

use traceroute -n , nslookup, and netstat -n to find the bottleneck depending on what the ping's show.

DNS works both ways...
IP -> NAME
NAME ->> IP

reverse arp (address resolution protocol) lookup is the resolution of name by ip, which is pulled apart left to right as opposed to the fully qualified domain name is pulled apart right to left.

 

[Credit123]

Hi Stanhubble,

These are the results of the tests you suggested I run:

Command Response Time in seconds

ping localhost by name 55
ping localhost by IP 29
ping DNS by IP 1
ping DNS by Name 1
ping Host by IP 1
ping Host by Name 1
ping client by IP 28
ping client by Name 55

Yes, the localhost is in the hosts file.

When nslookup is done on IP Addresses, all IP Addresses are resolved to their proper names. Traceroute -n on the server, client and localhost IP Addresses produces a quick response.

Thanks in advance,

Credit123

 

[stanhubble]

Are you using NIS ? (longshot...)

could you post what is in /etc/resolv.conf
and a netstat -nr

 

[Credit123]

Hi Stanhubble,

Here is the info you requested:

No, we are not using NIS.

resolv.conf:

domain cwwi.cwintra.com
search cwwi.cwintra.com
nameserver 172.20.3.122
nameserver 172.20.19.190
nameserver 172.19.104.27

netstat -nr:

Routing tables
Destination Gateway Flags Refs Use Interface
default 172.20.19.129 UGS 18 20174 net0
127.0.0.1 127.0.0.1 UH 4 6650 lo0
172.20.19.128/25 172.20.19.190 UC 1 0 net0
172.20.19.190 127.0.0.1 UGHS 6 12090 lo0
224/8 172.20.19.190 UGS 1 5 net0


Thanks in Advance,

Tuan

 

[stanhubble]

try adding the following to /etc/resolv.conf

hostresorder local bind / nis

if this works then i would guess that localhost is not configured properly on the dns (not likely but possible).

 

[Credit123]

Hi Stanhubble,

There is no option on GUI Screen for this option (hostresorder local bind / nis). Am I suppose to add this option directly the /etc/resolv.conf from the command prompt.

What does this option do?

As mentioned before below is the content of the resolv.conf:

domain cwwi.cwintra.com
search cwwi.cwintra.com
nameserver 172.20.3.122
nameserver 172.20.19.190
nameserver 172.19.104.27

Thanks in Advance,

Credit123

 

[Bonestein]

yes you need to put it in there manually. Type the following it should get you there.

cd /etc
vi resolv.conf
i hostresorder local bind / nis
:wq!

 

[stanhubble]

as bonestein said, yes you have to put it in manually, then try the pings again.

my first suggestion is get out of the scoadmin stuff and learn to do things at the command prompt and (not to sound snootty) learn to use man. ie man resolv.conf

host resolution order....