Network Troubleshooting?

Hi... All





I am Yash and working with NGOs. We have over internal network, in this network we have total 25 machines and two Dell servers one is proxy server and other is Application server. Half of Machine (15-16) in workgroup and other in Domain. We have BSNL Broadband connection for Internet. We have also updated Symantec Server edition.





The Problem is Internet access. Every three to five minute the BSNL modem automatically disconnects and we can ping the modem the error come like - Request time out. And we can not access the Internet.





We checked the modem through BSNL Officer and they says modem is ok, problem in your network





How we find where is the problem? Any software is check my network and finding error





Please tell me and guide me as soon as possible.....





With best regards





Yash

Network Troubleshooting?
This is a difficult to trouble shoot situation. You could try some "packet sniffing" software to see if a particular machine is causing the issue but that isn't the easiest thing to find.





I would go the following route, maybe faster.


1. How does the modem work with a single computer attached, all other networking items off! if it still disconnects then the wiring to it may be suspect or at the time BSNL checked it was working fine. Modems can cause this as can bad inbound lines and that can be very difficult to isolate unless the modem is checked over a longer time span than just a quick, yes it is working test!





2. Then start by "isolating" what is downline. I usually start with the first item that gets connected, like the switch or router. Then check with only ONE computer again! If the issue appears its that device! Then since you have both a DOMAIN and a workgroup. Connect ONLY the domain and see it the problem starts. If the problem appears, check the domain controller by itself and see it the problem still exists, if it does its that machine! You might also check all switches, routers, etc that are in use in the domain! (I have seen switches and routers just hang, Routers particularly!)





3. Then start connecting each workgroup machine one at a time. When you hit the one causing the issue you can then look at that machine, Viruses, trojans, anything that generates excessive traffic! Domain/workgroup collisions can indeed be at fault.





You might get a clue from the logs on the domain controller as well, see if anything "corresponds with the disconnects".





Good Luck - These aren't easy
Reply:Dial up connections are generally not recommended for a business of your size anymore. Also connection problems aside the BSNL bandwidth is probably not adequate for the demands that many users will put on it. If it is available you should consider getting permanent connection rather than Dial up, 1.5Mb or better.