?
Solved

Lost connection every 20 Min

Posted on 2004-10-02
13
Medium Priority
?
135 Views
Last Modified: 2010-04-14
We use windows 2000 server as SQL 2000 DB server.
IIS, FTP, SMTP are disbaled on the server.
The problem is that every 20 min or so the server cannot be seen by other machines on another subnet (same subnet can see it all the time).  We cannot ping, cannot remore connect, cannot see port 1433 (which is what we really need to see.
We remove the firewall so that cannot be the problem.  We installed a new NIC (3com) updaed drivers, so that is not the problem either.
We only use this machine as SQL server listening on port 1433.
the web servers stops seeing it until we reboot or the machine decided to start answering again.  
We do not have to reboot... if we wait long enough (10 min or so) it will start answering again.
The ISP does not see any special activity on the ports leading to our machine.
All windows updares were applied, no viruses (checked with latest Norton and housecall), Spybot check comes clean too...
Any ideas??  
0
Comment
Question by:dravisk
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 7
  • 3
  • 2
  • +1
13 Comments
 
LVL 51

Expert Comment

by:Netman66
ID: 12210610
How is the other subnet connected?

If you could provide your router and switch configuration (architecture) it might help us give you somewhere to start looking.


0
 

Author Comment

by:dravisk
ID: 12210628
It is hosted by a colo.... my understanding is that we have a VLAN with a few subnets all belong to our servers.   We have switch (simple 10/100 unmanagable switch) connected to the router and all our servers are hooked up to that switch.  My exit to the world is a single wire coming into the switch from the router.
0
 
LVL 58

Expert Comment

by:Julian Hansen
ID: 12211766
Just to clarify - your DB server is on a different subnet from the Web Servers?

You say that devices on the same subnet as the DB server can see it all the time even while devices on a different subnet cannot see it.

Can you give some more information about what devices you have and how they are connected.

From what I understand you have a DB server and some other devices (say A and B) on the same subnet so that A and B can always ping the DB right?
Where / what are the devices that are having trouble connecting to the servers - from your post I would imagine these to be your Web Servers yet you say all your servers are connected into the same switch - does this mean they are connected on different subnets to the same switch?

I am a bit hazy on exactly how things have been configured - could you elaborate a bit more.
0
Back Up Your Microsoft Windows Server®

Back up all your Microsoft Windows Server – on-premises, in remote locations, in private and hybrid clouds. Your entire Windows Server will be backed up in one easy step with patented, block-level disk imaging. We achieve RTOs (recovery time objectives) as low as 15 seconds.

 

Author Comment

by:dravisk
ID: 12211875
here we go:

Web server on IP 207.100.100.2   (subnet 207.100.100.1 - 16)
DB server on IP   207.101.40.2      (subnet 207.101.40.1 - 132)
In eddition I have on each subnet a couple other windows 2000 machines (Workstations)

Both are connected to the SAME switch which is connected to a router port.  The router had 4 subnets on this port 2 of which are the ones above.

When the system stops respoding - the Web server cannot ping or remote access the DB sever.  However a laptop with address 207.101.40.5 Can.   Then after a while (or after reboot), the Web server can again ping and remote access the DB server.

Intresting thing is, when the DB is not responding the DB machine cannot see the internet.

The more I think about it the ISP has some screwedup VLAN config... I am not sure how to approach it though...
0
 

Author Comment

by:dravisk
ID: 12211889
One more piece of information.  All the time the Web server is accessible from same subnet, other subnets, Internet.
0
 
LVL 58

Expert Comment

by:Julian Hansen
ID: 12211935
Can the laptop or the DB server see any of the other machines on the Web Server subnet i.e. after the problem happens and the Web Server can't see the DB can any machine from 207.101.40.0 see any machine from 207.100.100.0? What I am getting at is can we eliminate the DB server as the problem and try and establish if it is not something in the switch say? If this problem occurs and other devices can see each other across the subnets then the problem is likely in the DB server if this is not the case it is more likely to be a problem in the switch?

Have you done any network scans to see what traffic if any, there is on the network?


0
 

Author Comment

by:dravisk
ID: 12212196
Traffic is low at the time we have the problem.
I know the laptop on 207.101.40.5 can see the DB server and the DB can see it all the time.
0
 
LVL 9

Expert Comment

by:imnajam
ID: 12213130
before giving a comments I would like to know what are the even taking place at that time........check out the event logs and let me know if there is any error/warning or info

all the best
0
 

Author Comment

by:dravisk
ID: 12213182
Event log is clear.  No entries in the system/security or application at that time.
0
 
LVL 51

Accepted Solution

by:
Netman66 earned 1500 total points
ID: 12213289
So, your servers are physically connected to the same switch but reside on different subnets.  This would mean any traffic destined for one subnet from the other would pass through the router.

My guess here would be something on the router is not 100% or there is something in the routing table on the SQL server that is causing lost routing.

Can you run a ROUTE PRINT from the SQL box and output it to a text file to copy and paste here?

Thanks
0
 

Author Comment

by:dravisk
ID: 12214385
===========================================================================
Interface List
0x1 ........................... MS TCP Loopback interface
0x1000003 ...00 0a 5e 45 bb f4 ...... 3Com EtherLink PCI
===========================================================================
===========================================================================
Active Routes:
Network Destination        Netmask          Gateway       Interface  Metric
          0.0.0.0          0.0.0.0     207.101.40.1    207.101.40.2        1
        127.0.0.0        255.0.0.0        127.0.0.1       127.0.0.1        1
     207.101.40.0  255.255.255.240     207.101.40.2    207.101.40.2        1
     207.101.40.2  255.255.255.255        127.0.0.1       127.0.0.1        1
    207.99.42.255  255.255.255.255     207.101.40.2    207.101.40.2        1
        224.0.0.0        224.0.0.0     207.101.40.2    207.101.40.2        1
  255.255.255.255  255.255.255.255     207.101.40.2    207.101.40.2        1
Default Gateway:      207.101.40.1
===========================================================================
Persistent Routes:
  None
0
 
LVL 51

Expert Comment

by:Netman66
ID: 12215661
That looks fine.

How about the same from your Web server?

0
 

Author Comment

by:dravisk
ID: 12341299
Just wanted to let you know the problem is solved.  It was a router issue some double enties same IP in 2 VLANs.  So every once in a while the other VLAN will thing the IP is there rather then on our VLAN
0

Featured Post

Free Tool: Site Down Detector

Helpful to verify reports of your own downtime, or to double check a downed website you are trying to access.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

NTFS file system has been developed by Microsoft that is widely used by Windows NT operating system and its advanced versions. It is the mostly used over FAT file system as it provides superior features like reliability, security, storage, efficienc…
Instead of error trapping or hard-coding for non-updateable fields when using QODBC, let VBA automatically disable them when forms open. This way, users can view but not change the data. Part 1 explained how to use schema tables to do this. Part 2 h…
Add bar graphs to Access queries using Unicode block characters. Graphs appear on every record in the color you want. Give life to numbers. Hopes this gives you ideas on visualizing your data in new ways ~ Create a calculated field in a query: …
Have you created a query with information for a calendar? ... and then, abra-cadabra, the calendar is done?! I am going to show you how to make that happen. Visualize your data!  ... really see it To use the code to create a calendar from a q…

719 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question