[Fourlanders] Ethernet Switches

[Brian McCarthy]

We used a 10/100 5 port switch in the "great white" trailer in June and 
September. We had as many problems within that trailer as we had in the 
other trailer. I did find a problem that caused very similar 
connectivity issue between my PC's when I tried to use them with 
Writelog at home. After a couple of settings changes, I was able to 
maintain Writelog connectivity for weeks at a time. All of the issues 
were related to the firewall aspects of Win-XP, EVEN THOUGH I HAD TURNED 
OFF THE FIREWALL. XP seems to be determined to protect you in spite of 
yourself and explicit instructions to not protect anything.

I have the details in my notes. The notes are a bit buried at the 
moment. I will pull them out later. Another switched hub and a spare is 
not a bad idea. I believe running more than one ethernet cable between 
the trailers is asking for trouble. Bandwidth was not the issue. Even at 
10MB. The Win XP firewall still being active (though "turned off" in all 
the screens) was the problem.

More details later...

Brian
NX9O


Paul Yeager, ABR(R), REALTOR(R) wrote:

>Ron:
>   
>  If we're concerned primarily with communications between workstations and the server, then logically (ignoring physical cable layout for the moment), we have a star netwrk, with the server at the center.  In this configuration, it seems there would always be the potential for contention anytime two workstations attempt to send traffic to the server.  We might move the point of contention by changing the cable layout/net topology, bit not eliminate it.  Your suggestion would appear to move the pooint of contention to the switch's internal bus and the ethernet run to the server from the switch.
>   
>  Having said this, it seems unlikely that contention would be a significant problem, considering the volume of traffic.  Ethernet is designed to handle and re cover from collisions.  My suspicion is that our problem don't stem from network topology, except to the extent that topology might affect RF interference problems, which I suspect is the primary cause.
>   
>  It's also possible that there is some aspect of the software we're using that is the culprit.  Does anyone else have trouble running writelog in a configuration similar to ours?
>
>"Rogers, Ron" <RR124640 at ncr.com> wrote:
>      Paul:
>  Your reference to MAC address routing and "sub netting" is correct. But I used the term "sub net" referring to a hardware device topology.
>   
>  This is because it forces all traffic of the 2 or 3 stations in the second trailer through a single port of the switch in the second trailer to a single port on the first switch in the first trailer over a single Cat-5. I probably should have used the words "secondary LAN branch" rather than "sub net".
>   
>  This topology opens the gate for network "collisions" and "retries", which is one contributing factor we had considered in debugging the network crashes.   A more robust and faster running network concept (at least in my mind) would be to use a single 5 or 6 port switch (I previously mentioned a router but could be a switch) right off the Server PC in the first trailer and use dedicated Cat-5 cable drops to each station.  
>   
>  That was the real point I was offering up for consideration. 
>      Ron 
>  WW8RR 
>
>
>   
>
>    
>---------------------------------
>  From: Paul Yeager, ABR(R), REALTOR(R) [mailto:paul at mtnlist.com] 
>Sent: Thursday, February 02, 2006 4:46 PM
>To: Rogers, Ron
>Subject: Re: [Fourlanders] Ethernet Switches
>
>
>  
>  "Rogers, Ron" <RR124640 at ncr.com> wrote:
>    Do we want to use multiple switches that would still create a "sub net" to the second trailer. 
>
>  In what way does using a switch create a sub net?  You might do that with a router, but as I understand it, a switch routes traffic based on the MAC address, without regard to IP address.  Therefore, no sub net would be necessary, nor would one be created by the use of multiple switches.
>   
>  Perhaps I'm off the reservation here, and if I am, I'd love to be reeled back in.
>   
>  Best regards,
>  
>
> 
>
>
>Paul Yeager, ABR®, REALTOR®
>Broker Associate
>Four Seasons Realty Group, Inc.
>828 400 9442 (cell)
>828 926 7517 ext 205
>800 554 6356 ext 205
>paul at mtnlist.com
>www.mtnlist.com
>
>What is ABR®? Find out at http://www.rebac.org   
>
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>