Home > Ask the Networking Experts > Network administration Questions & Answers > Troubleshooting your network
Ask The Networking Expert: Questions & Answers
EMAIL THIS

Troubleshooting your network

Lindi Horton EXPERT RESPONSE FROM: Lindi Horton

Pose a Question
Other Networking Categories
Meet all Networking Experts
Become an Expert for this site


Digg This!    StumbleUpon Toolbar StumbleUpon    Bookmark with Delicious Del.icio.us   


>
QUESTION POSED ON: 05 October 2006

I have problem in my networking strategies.

After 6:30 PM my network goes down. We are not able to get the mapped drives on local machines and we cannot save anything on our server. We have a Dell Poweredge 2800 server with Microsoft 2003 as our operating system. We have recently put Pix 515 firewall on the switch (D-Link DES 3550). In the daytime it works very smoothly, but by evening it chokes. We have scanned all the machines with Trend Micro for viruses and found that there are none. Please suggest something I can do.


>

This is an interesting problem. As with all troubleshooting problems of this magnitude and impact, the creation of a true problem statement and investigation into that is essential to understanding how to resolve the issue.

To troubleshoot this issue, I would suggest loading up some packet analyzers to try to isolate and find the problem. For example, I would have network monitoring captures on the servers going on during the time that you have issues. This would help you understand if there are packets actually arriving at the servers and whether or not the servers are responding to those requests. This would allow you to see if it is the network or the server that is experiencing the problem. It would also show you if the server is being overloaded with backup or other types of traffic that might cause it to stop responding to other types of requests. You would see a lot of RST bits set if the servers are resetting sessions. This would be the first start. Alternatively, you can start looking at either getting a tap or doing a SPAN (port mirror) to determine what the traffic patterns look like. NetFlow and other IP accounting technology also would help determine where traffic is going and what protocols are consuming the traffic to impede response time.


Digg This!    StumbleUpon Toolbar StumbleUpon    Bookmark with Delicious Del.icio.us   



RELATED CONTENT
Network administration
How do I access Windows Server 2003 remotely if I've lost my admin password?
What network troubleshooting tools can I use to determine the cause of slow web page access?
How does Active Directory for Cisco ACS work?
How do I set the Web page default on a network of computers without setting them all individually?
What IP enables file sharing among multiple computers on different Internet connections?
Why is access denied to my Active Directory (AD) users and computers?
What network loss testing tools/methods calculate dropped packets from a PC?
Do I have to disable DHCP on my router to create a DHCP server?
What preventative maintenance procedures for network devices exist?
Is there VLAN software recommend for Realtek NICs?

LANs (Local Area Networks)
Cisco's refreshed stackable switches for new era of campus LAN design
VLAN guide for networking professionals
LAN edge switch security functions: Switch ACLs; filtering port traffic
How do I access Windows Server 2003 remotely if I've lost my admin password?
How does Active Directory for Cisco ACS work?
Two colleges switch to Enterasys in order to escape ACL programming
2010 predictions: What routing/switching trend will affect networking?
Gigabit Ethernet backbone switch allows school to digitize classes
Frame relay vs. ATM networks: What's the difference?
Best of 2009: Computer networking advice

Working With Servers and Desktops
2010 predictions: What IT trends will change networking fundamentals?
How do I set the Web page default on a network of computers without setting them all individually?
What network loss testing tools/methods calculate dropped packets from a PC?
Do I have to disable DHCP on my router to create a DHCP server?
How can I replicate the services of Active Directory (AD) in ADC?
Top 10 reasons why computers do not have network access to each other
Troubleshooting -- 'Network Know-How' Chapter 17
Windows Server 2008 IP routing configuration: Static and dynamic RIPv2
Understand Windows tracert output to troubleshoot network connectivity
Test your TCP/IP protocol stack to troubleshoot network connectivity

RELATED GLOSSARY TERMS
Terms from Whatis.com − the technology online dictionary
32-bit IP addressing  (SearchNetworking.com)
ARCNET  (SearchNetworking.com)
master  (SearchNetworking.com)
master/slave  (SearchNetworking.com)
Port Address Translation (PAT)  (SearchNetworking.com)
subnet  (SearchNetworking.com)
subnet mask  (SearchNetworking.com)
system administrator  (SearchNetworking.com)
Technical Office Protocol  (SearchNetworking.com)
virtual systems management  (SearchNetworking.com)

RELATED RESOURCES
2020software.com, trial software downloads for accounting software, ERP software, CRM software and business software systems
Search Bitpipe.com for the latest white papers and business webcasts
Whatis.com, the online computer dictionary



Search and Browse the Expert Answer Center
Search and browse more than 25,000 question and answer pairs from more than 250 TechTarget industry experts.
Browse our Expert Advice



Expert networking advice and tips for IT professionals
About Us  |  Contact Us  |  For Advertisers  |  For Business Partners  |  Site Index  |  RSS
SEARCH 
TechTarget provides technology professionals with the information they need to perform their jobs - from developing strategy, to making cost-effective purchase decisions and managing their organizations' technology projects - with its network of technology-specific websites, events and online magazines.

TechTarget Corporate Web Site  |  Media Kits  |  Site Map




All Rights Reserved, Copyright 2000 - 2010, TechTarget | Read our Privacy Policy
  TechTarget - The IT Media ROI Experts