Network connection issue...

  • Thread starter Thread starter Brad Pears
  • Start date Start date
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Brad Pears

We recently moved two of our users to a different location in the building.
Both of them moved their computers with them.

Now, both of these users are experiencing issues I beleive related to the
number of add'l switches they are having to go through to get where they
want to go on the LAN...

One user is having all kinds of problems plotting his drawings that he never
had before. Sometimes the drawings will be printed with only a portion of
the drawing being present. Other times it seems fine. He never had this
issue where he was located before.

The other user we moved (they are both sitting beside each other now and
plugged into the same switch) is complaing that his system seems slower when
he is trying to open up drawings and other files across the network. He says
it was never this slow where he used to sit.

Basically the only thing that has changed for both of these users is that
they are now having to go through two additional switches as compared to
where they used to sit, before their data gets to the plotter or servers
where they keep their data.

One switch is a Dell 10/100 24 port switch and currently only three
connections are even used...

The other switch is a 5 port Startech switch of which four of the five ports
are being used...

Could this be the isssue? Should we be looking at re-wiring so as to avoid
having them going through this many switches? Or, should we be upgrading the
switches? The ones we have are not exactly the most expessive ones out
there!!

One reason why we have all these switches is that we work in a log home and
it is really difficult to wire and as such a network of switches has been
implemented to help us get around these issues...

Thanks,

Brad
 
Brad Pears said:
We recently moved two of our users to a different location in the building.
Both of them moved their computers with them.

Now, both of these users are experiencing issues I beleive related to the
number of add'l switches they are having to go through to get where they
want to go on the LAN...

One user is having all kinds of problems plotting his drawings that he never
had before. Sometimes the drawings will be printed with only a portion of
the drawing being present. Other times it seems fine. He never had this
issue where he was located before.

The other user we moved (they are both sitting beside each other now and
plugged into the same switch) is complaing that his system seems slower when
he is trying to open up drawings and other files across the network. He says
it was never this slow where he used to sit.

Basically the only thing that has changed for both of these users is that
they are now having to go through two additional switches as compared to
where they used to sit, before their data gets to the plotter or servers
where they keep their data.

One switch is a Dell 10/100 24 port switch and currently only three
connections are even used...

The other switch is a 5 port Startech switch of which four of the five ports
are being used...

Could this be the isssue? Should we be looking at re-wiring so as to avoid
having them going through this many switches? Or, should we be upgrading the
switches? The ones we have are not exactly the most expessive ones out
there!!

One reason why we have all these switches is that we work in a log home and
it is really difficult to wire and as such a network of switches has been
implemented to help us get around these issues...
Click to expand...

This sounds more like a collision or cabling issue rather than a switch
failing. Specially if other users are not affected and the two who are,
are seated next to each other.

Have you tried Pinging other devices on the LAN from these two PC's to
see if you have any packet loss and / or increased response times. Also
check where the LAN cables are routed (ie: they should not be following
mains cables and should only cross such cables at 90 degrees). Check
cable length limits between switches, PC's etc (ie: end to end cable
lengths etc should not exceed 100m - ideally no more than 90m).
 
Sounds like a bad cable or cable end to me...

look for a "crushed" cat5 that may have been rolled over or cable end not
tight into connector.

also try switching the switches....swap them and see if problem moves
elsewhere...

make sure total length from switch is not >275 feet.
HTH

RickD
 
Is there some kind of software we can download and run to test for
collisions between two endpoints? i.e. these PC's being one endpoint and
the other being maybe a PC on the other side of the switches somewhere?

Ping does not really give you much in the way of troubleshooting does it?
Other than tell you there was data loss etc...

Thanks,

Brad
 
I vaguely remembered something about a 5-4-3 rule for ethernet but this page
set me straight.

http://www.comptechdoc.org/independent/networking/guide/nethwethernet.html

I don't think it's the additional switches.


Brad Pears said:
Is there some kind of software we can download and run to test for
collisions between two endpoints? i.e. these PC's being one endpoint and
the other being maybe a PC on the other side of the switches somewhere?

Ping does not really give you much in the way of troubleshooting does it?
Other than tell you there was data loss etc...

Thanks,

Brad
Click to expand...
 
Brad Pears said:
Is there some kind of software we can download and run to test for
collisions between two endpoints? i.e. these PC's being one endpoint and
the other being maybe a PC on the other side of the switches somewhere?

Ping does not really give you much in the way of troubleshooting does it?
Other than tell you there was data loss etc...
Click to expand...

<Snip>

I do not know of any real software to monitor collisions as this should
really be done via proper hardware monitoring devices (and there not
cheap). There are some smaller hardware units available for $100 or more
(ie: a bit more than just a cable tester). However, a simple cable
tester is enough to prove whether a cable is damaged or faulty.

You may have some facilities on the switches you have already (can't
answer because I have not used either of your two personally). My 3Com
units provide alot of packet received / sent / lost and collision data
even down to a port level. However my D-Link switches only provide a
collision LED on front panel for each port.

Do a Google for "Packet Sniffing Software" ...

Why not buy or borrow some spare cables and do a quick test via running
the cable through the doors / garden / whatever just to prove length is
not an issue.

Also investigate where the existing cables run. Do they pass any
equipment that generates strong electrical or magnetic fields. I had one
customer who kept returning a Notebook claiming it was loosing BIOS
settings and we could NOT find any faults. During a random visit to site
we noticed where he was using the Notebook and the other side of the Dry
Wall was an Arc Welding Machine. His problem only occured when it was
used. In otherwords, environmental issues may be effecting you.
 
SuperGumby said:
I vaguely remembered something about a 5-4-3 rule for ethernet but this page
set me straight.

http://www.comptechdoc.org/independent/networking/guide/nethwethernet.html

I don't think it's the additional switches.
Click to expand...
5-4-3 rule is for hubs.. Switches break-up collision domains, so there
should not be a problem.

Get a length of cable. Punch it down on some sockets, and just run it
down the corridor between the Server and the two workstations. Use some
bought-in patch leads to connect to the 'Server switch' and one
workstation. - Try that.. it will prove whether there is a problem.

Disconnect from Server. Move that connection to next switch, and try
again.

You can work through to find the area where the problem is.

Also, try locking the NIC settings for speed and duplex on the
workstations. - Some NIC / Switch combinations didn't like each other,
and data was dog-slow.

Another thought..
Can you slightly reconfigure the way the switches are arranged?
Feed the Server into a switch. Run a feed from this switch to each of
the others. - These would be where there are a cluster of machines.
This is known as a 'collapsed backbone', and reduces the number of bits
of kit the data goes through.

HTH
Phil Partridge
(e-mail address removed)
Remove the grit to reply
 
Thanks for your help. It appears that the issue was definately related to a
bad cable. I got a cable tester and discovered that one pair was not
functioning properly - although the cable still did!! Without an actual
tester to tell me which pairs were bad, I would have been spinning my wheels
becuase the cable appeared to be fine...

Brad
 
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