Re: Server not listening - Mailing list pgadmin-support

From Joris Dobbelsteen
Subject Re: Server not listening
Date
Msg-id 73427AD314CC364C8DF0FFF9C4D693FF037ACB@nehemiah.joris2k.local
Whole thread Raw
In response to Re: Server not listening  (George Heller <george.heller@yahoo.com>)
Responses Re: Server not listening
List pgadmin-support
Adding SSH makes the mix makes it all slightly more complicated. Now let us first find where its going wrong:
 
If I scan the previous e-mails I come up with the following (please correct me if I'm wrong!!!):
 
  1. Your postgresql server (linux) and client (XP) are on different machines.
  2. The server and client are on different subnets, meaning there must be at least one router inbetween.
On the server (Linux):
  • The server is actually running (the 'ps' output gives this evidence).
  • On the server you can connect to 5432 port on the remote IP.
    This gives the evidence that the postgresql server is listening here.
  • Which Linux distribution you happen to use?
On the client (XP):
  • It cannot connect to the postgresql server.
  • The firewall is disabled (though the WIndows Firewall does not block outgoing connections).
Intermediate systems:
  • The MUST exist (since server and client are not in the same subnet). But no information is known about these.
  • There is a working path between the client and server (since we can do some things).
  • Not under George its control(?)
    Seems this way, not sure, may, or may not, be important...
Please ensure the above assertions are valid, they are important for diagnosing where the problem is.
I think the next best step is to identify what your network looks like:
 
On the XP machine execute the following two commands in the DOS prompt:
"ipconfig /all"
"tracert <postgresql server>"
"telnet <postgresql server> 5432"
   (How fast do you get a response, within ~5 seconds or it takes longer?)
 
On the XP machine, see if you have any firewall installed. This is current a great pain in several situations. Other software that might interfere is:
  • Network Associates McAfee Virus scanner (8.0 and onward)
  • Network Associates McAfee Firewall
  • Symantic Internet Security
  • Kapersky
  • ZoneLabs
  • ...
  • ...
 
On the Linux server:
"ifconfig"
"tracepath <client>"
"iptables -L"
 
On the linux server start the following while trying to connect:
"tcpdump port 5432"
For each test, include wheter you see no, few or a lot (more than a screen) of packets. You should also see the word ack a lot of times.
 
I would really consider picking up one of the boxes and putting them on the same subnet. This reduces the complexity caused by the intermediate systems and might reduce the problem to the intermeidate systems only.
Alternatively pick any box on the server its network and do a telnet to <postgresql server> at port 5432. If this works, the problem is most likely in the intermediate systems (or client).
 
Also try it from your own client at its current location. Ensure that during tries the tcpdump tool is running.
 
Hopefully this leads us a little closer to finding the actual problem.
I have the strong feeling that either the server has the firewall configured or, more likely, that any intermediate system doesn't forward this traffic.
 
- Joris Dobbelsteen
 


From: pgadmin-support-owner@postgresql.org [mailto:pgadmin-support-owner@postgresql.org] On Behalf Of George Heller
Sent: woensdag 25 april 2007 18:05
To: andy.shellam-lists@mailnetwork.co.uk
Cc: pgadmin-support@postgresql.org
Subject: Re: [pgadmin-support] Server not listening

Hi,
 
Thanks for that mail. I tried to follow the steps to create a tunnel, but when I add the connection, I dont really see an option to Save the settings. So make the changes and log in to my server with the actual hostname, it logs me in. I open another session on Putty, and the changes I made in the port forwarding are gone, I make the changes again, and try to log in using 'localhost' this time, it says Connection refused.
 
I also tried logging into PgAdmin using localhost, but it gave me the same error as before, only this time it said ip address 127.0.0.1
 
Thanks.
George.

Andy Shellam <andy.shellam-lists@mailnetwork.co.uk> wrote:
 [snip] 

pgadmin-support by date:

Previous
From: Andy Shellam
Date:
Subject: Re: Server not listening
Next
From: Andy Shellam
Date:
Subject: Re: Server not listening