Re: SQL clients dropping connections on WAN

From: David Bock (David_at_dvbock.com)
Date: 07/10/04 

Date: Sat, 10 Jul 2004 08:49:38 -0500

Thank you so very much for your help.....
-> the problem appeared when we changed connections from ISDN to DSL, so
part of me thinks a configuration is wrong in the new set of routers. The
problem I have with this is that we have checked and re-checked every
configuration on the VPN tunnels. We actually have much better connectivity
now than with the ISDN lines; we can now Ping other nodes in the network
(star topology) where before we could only see the central hub. Wins is
running and replicating with all partners (for the win9x machines). DNS is
set up and is resolving cerrectly to the best of my ability to test (I would
like to test the routing on SQL packets, but can only do a general DNS
resolve). I can transfer files over the connections, See the Exchange
Server, even see the SQL 2000 server. The SQL2000 server is on the primary
GCC for the forest. Pinging works too.

Topology. Star Topology, the central hub (A) has:
 The Primary GCC
 -> is running Win2000(latest SP), SQL2000(latest SP) (DNS, WINS are
running too)
 -> When we changed out the connection I added SP (I think it was 3, but it
is the latest) We upgraded this machine from NT4 and the partition on the HD
was too small to allow the SP patch. I found and removed a file usr.dmp
before I could do the update.
 The second server is dedicated to running Exchange 2000 (latest SP)
 -> no problems with updates on this machine
 -> Secondary DNS server. The only change made when we did the DSL switch
was to remove a static DNS route (and to change the gateway to the firewall
rather than the router which we pulled out of the network.
 The third server in the hub is a file/printer sharing computer.
 The forth server is actually on it's own subnet in the DMZ of the firewall
(it is our web server)

Location (B)
 has one Win2000 server that is running DNS and Wins. Is a member of the
root domain. no changes were made to this box when we changed to DSL, we
swapped the ISDN router for a firewall with VPN and Content filtering. (same
brand as the firewall in (A))

 Location (C)
 Has a Win2000 Server in it's own trusted domain (DNS,WINS) Again, no
settings were changed. We have a firewall/VPN from a different company (it
was actually there and in place before we changed, this was our test
location. We changed ISP's.

  Location (D)
 Has a Win2000 Server in it's own trusted domain (DNS,WINS) Again, no
settings were changed. we also have an older firewall/VPN from a different
company.
-------------
Before we changed (A) could see everybody, but seeing between (B),(C) and
(D) was spotty. File transfers were spotty. Now it works great.
I am thinking it is something simple, because it is working differently on
different machines in different nodes. I started out on the network board,
but after I tested all of their suggestions I came here.

Clients in (A) have no problems.

In (B) and (D) the Win2000WS that our bookeeper uses has a problem where it
takes a while to connect, but has no drop off problem. Other workstations
when left unused for 5-10 minutes will loose the connection to the SQL
server and need to be rebooted.

In (C) we have the same problems with the additional problem of it taking 4
seconds to fill each drop down list when you access it on each screen. This
makes data-entry a pain, and when we run our reports it takes a very long
time.
-----------
The only error message we get is a Time-out message on the connections from
the Workstations, and it is set to "Don'tTime-out" on the server.
-----------
We are using a custom application that was designed for us, and rge DB
programmer I used is also trying to figure out why it stopped working.
-----------
Pinging works great, and I don't see any lost packets.
-----------
I think that AUTO_CLOSE and AUTO_SHRINK are OFF.
I am not sure about these on the database, I didn't know about these
settings. I will check later today.
The Tunnels are persistent and do encrypt. I do not think they shrink the
packets. I will double check later today or Monday (My Firewall expert is
out of town for the weekend, and he set up the tunnels)
-------------
Thanks again Mingqing, if I may call you that.
I would apreciate any further insight

""Mingqing Cheng [MSFT]"" <v-mingqc@online.microsoft.com> wrote in message
news:WWXGFLkZEHA.3168@cpmsftngxa06.phx.gbl...
> Hi David,
>
> From your descriptions, I understood that you will lost connections by
> means of DSL. Have I understood you? If there is anything I misunderstood,
> please feel free to let me know:)
>
> First of all, by what you are using to connect SQL Server? SQL Server
> Enterprise Manager or Query Analyzer or you own applications? Will there
be
> any error message or scenraio when you are losing the connections? What
are
> they? Could you show me some detailed information of them?
>
> Secondly, I am not very sure whether you connections via DSL are stable.
If
> you use PING command (for example, you could right the command like this
> "ping <servername or ip address> -t", no quotation mark) what's the
result?
> Any large lose of packages?
>
> Thirdly, have you checked that AUTO_CLOSE and AUTO_SHRINK are OFF?
>
> Thank you for your patience and cooperation. If you have any questions or
> concerns, don't hesitate to let me know. We are here to be of assistance!
>
>
> Sincerely yours,
>
> Mingqing Cheng
> Microsoft Developer Community Support
> ---------------------------------------------------------------
> Introduction to Yukon! - http://www.microsoft.com/sql/yukon
> This posting is provided "as is" with no warranties and confers no rights.
> Please reply to newsgroups only, many thanks!
>

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