Solved

Lost connection every 20 Min

Posted on 2004-10-02
13
128 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
  • 7
  • 3
  • 2
  • +1
13 Comments
 
LVL 51

Expert Comment

by:Netman66
Comment Utility
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
Comment Utility
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 51

Expert Comment

by:Julian Hansen
Comment Utility
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
 

Author Comment

by:dravisk
Comment Utility
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
Comment Utility
One more piece of information.  All the time the Web server is accessible from same subnet, other subnets, Internet.
0
 
LVL 51

Expert Comment

by:Julian Hansen
Comment Utility
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
Free Gift Card with Acronis Backup Purchase!

Backup any data in any location: local and remote systems, physical and virtual servers, private and public clouds, Macs and PCs, tablets and mobile devices, & more! For limited time only, buy any Acronis backup products and get a FREE Amazon/Best Buy gift card worth up to $200!

 

Author Comment

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

Accepted Solution

by:
Netman66 earned 500 total points
Comment Utility
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
Comment Utility
===========================================================================
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
Comment Utility
That looks fine.

How about the same from your Web server?

0
 

Author Comment

by:dravisk
Comment Utility
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

Top 6 Sources for Identifying Threat Actor TTPs

Understanding your enemy is essential. These six sources will help you identify the most popular threat actor tactics, techniques, and procedures (TTPs).

Join & Write a Comment

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…
Possible fixes for Windows 7 and Windows Server 2008 updating problem. Solutions mentioned are from Microsoft themselves. I started a case with them from our Microsoft Silver Partner option to open a case and get direct support from Microsoft. If s…
It is a freely distributed piece of software for such tasks as photo retouching, image composition and image authoring. It works on many operating systems, in many languages.
This video shows how to remove a single email address from the Outlook 2010 Auto Suggestion memory. NOTE: For Outlook 2016 and 2013 perform the exact same steps. Open a new email: Click the New email button in Outlook. Start typing the address: …

763 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

Need Help in Real-Time?

Connect with top rated Experts

8 Experts available now in Live!

Get 1:1 Help Now