Network traffice.

Ok here is my problem or at least I think so.  I think my network seams to be slow and I cant even seem to hand multicast our school district went to Altiris  to deploy images to computer other schools are able to image a whole lab of computers with out any problems. I end up getting mixed results some work fine while others seam to time out and hang.  So I downloaded Wireshark and did a quick capture there seam to be a lot of ARP requests going on is this normal.  I dont know much about monitor network traffic but there sure seems like a lot of them.  I would say they make up for almost 90% of what I captured. I have a feeling the equipment can handle multicast but have a sneaking feeling something is miss configured that would speed things up.  All the major switches in my school are 3com 3250s all tied in by fiber in the 3com core builder 9400. Most of my labs have Netgear 16 port switches or 24 in them.  
LVL 3
dsexton18Asked:
Who is Participating?
 
Bill BachConnect With a Mentor PresidentCommented:
This would be a configuration item on each device.  A quick scan through the 3com manuals should provide this information.  Again, though, this may be quite normal, and changing it may prevent networking changes from resolving as quickly as you might like.

Are you sure that this is a problem?  The level of network traffic (under 100/second) doesn't indicate any real performance issues.  I think you need to look for a different culprit.  I'd start by spanning a trunk port onto the analyzer & see if you see anything there first...
0
 
dsexton18Author Commented:
ARP made up for 83% of what I Captured.  Is that normal
0
 
Bill BachPresidentCommented:
Post the capture file, and we'll have more information.

Also, please note that a network analyzer can ONLY see traffic bound for that machine.  You would need either a full-duplex tap or a switch configured to route ALL traffic to the monitor port to be able to see ALL traffic.

Since ARP inquiry traffic is broadcast to all nodes, you will always see ARP traffic from EVERY node on the network.  Thus, if you monitor any switched network from an otherwise-idle machine, you will naturally see a bunch of ARP traffic.  If the computer is doing nothing else, and other broadcast traffic is limited, then you'll see a high percentage of ARP packets.

To really get a good picture, replace your core switch with a hub (just temporarily), and monitor everything that comes through for a little while.  You'll see a much better picture of the real traffic.
0
Improve Your Query Performance Tuning

In this FREE six-day email course, you'll learn from Janis Griffin, Database Performance Evangelist. She'll teach 12 steps that you can use to optimize your queries as much as possible and see measurable results in your work. Get started today!

 
dsexton18Author Commented:
I would love to plug in a hub but since I am not the one in charge of the network I probably better not.  I did how ever contact him about my problems.   Attachedk is the text of a 60second captuere I did today.  
network.txt
0
 
Bill BachPresidentCommented:
A quick GREP-based analysios showed that there were about 4900 ARP packets in a 60-second interval, or 81 ARP/Second.  This is probably acceptable for a large network.  If you find the greatest offenders and increase their ARP timeout values, you might be able to reduce this a bit...
0
 
dsexton18Author Commented:
How do I increase the arp time out?
0
 
dsexton18Author Commented:
cool thaks .....i think i finnaly got the network guy convinced there are problems with our network. ....so hopefully he will come out soon.....
0
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

All Courses

From novice to tech pro — start learning today.