[OPLINTECH] Internet Problems

[Chad Neeper]

The fact that when the problem occurs, your RDP session is still working 
helps to rule out your local network as the source of the problem. You 
say that your RDP session is to your remotely hosted catalog. So, 
presumably, TCP/IP packets are able to get from your workstation, 
through your local network, out your gateway and off to the Internet 
(your remotely hosted catalog) and back. In general, it sounds like the 
network is working.

If the problem is only affecting the browser, then it sounds like you 
need to focus on things that would cause the browser to not work. The 
problem affects multiple machines, so the problem is more likely to be 
centralized. If you have a proxy or caching server that proxies and/or 
caches HTTP traffic, that would be a good place to check. It would only 
affect HTTP traffic. You could also verify that DNS is resolving 
correctly when the problem occurs. If the URL can't be resolved to an IP 
address, it could act as you described.

If you don't have an HTTP proxy and DNS is resolving when the problem 
shows up, check the configuration on a problem workstation. See if an 
HTTP proxy has been configured on the workstation. There shouldn't be 
one configured if you're not using one. A malicious program 
(virus/worm/trojan/spyware) can use a hidden proxy on the workstation to 
intercept HTTP traffic. Malicious programs can, in general, also 
interfere with network traffic to and from a workstation. It's worth 
while to verify that the workstations are clean.


Also, to answer your question about satellite, etc. interference on the 
wired network: Very unlikely. If there was a network disruption of that 
sort, a bad cable, network cables running along power cables causing 
interference, etc., the network problems would affect ALL network 
traffic; not kill the browser and leave your RDP session working.


Hope this helps,
Chad

-----------------------
Chad Neeper
Senior Systems Engineer

Level 9 Networks
740-548-8070 (voice)
866-214-6607 (fax)

--   Full LAN/WAN consulting services   --
-- Specialized in libraries and schools --



shivelri at oplin.org wrote:
> Ok, here goes. I work for a small library in Greenville Ohio, we are 
> having a problem with our Internet since moving into our temporary 
> location. The problem is that occasionally when using the Internet the 
> browser seems to lose connection and no longer can navigate to pages. 
> It is important to note that some of these computers are running an 
> RDP for our remotely hosted catalog, the RDP still will work when this 
> happens on them. The remedy to this problem is normally to reset the 
> connect via restart or repair connection, some times all it takes is 
> closing the browser and re-opening it. These problems are sporadic 
> making them extremely a pain in the butt. It's as though only the 
> application layer of the connection is effected.
>
> Solutions I have tried:
> I have replaced the previous switch with a new one (needed to do this 
> anyway it was old and I think was hit by a power surge).
> I have checked all the CAT5e cables with a cable tester, they were fine.
> I have had OPLIN run a usage test for me, we are not using that much 
> of our bandwith.
> The only thing effected systems have in common program wise is the OS, 
> MS Windows XP.
> Checked the switch, no restrictive setting are set there.
> Also check to make sure there was no Cables running against florescent 
> light fixtures, there aren't.
>
> If you have any ideas I would love to hear them.
>
> PS
> A thought just accrued to me, that when we first came into this 
> building we had a similar problem with our wireless connections. To 
> solve the problem I upped the transmitting frequency of the wireless 
> router, it fixed the problem. I assumed that a satellite dish or other 
> such device was causing the interference. Could this also be the case 
> with the wired connection? If so what can I do about that?
>
> _______________________________________________
> OPLINTECH mailing list
> OPLINTECH at oplin.org
> http://mail.oplin.org/mailman/listinfo/oplintech
>   
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