Solved

Weird network problems > time outs & DHCP not working correctly !?

Posted on 2013-12-28
8
334 Views
Last Modified: 2014-01-04
When I try to  ping my servers then I'm getting sometimes immediately a ping reply and sometimes time outs ... the patterns often seem to be ping reply, timeout, ping reply, timeout etc. This happens when pinging anyone of my servers.

Any ideas why?

Also, most of my PCs are not getting IP addresses from the DHCP servers ... how could I find out why that's the case??

Thanks a lot!
0
Comment
Question by:Xeronimo
8 Comments
 
LVL 93

Expert Comment

by:John Hurst
ID: 39743603
The first thing I would try is to restart the Server, make sure DHCP started and is running properly and then test again.

If the Server is working well, take a good PC to a switch very near the server and try it. You could have a  problem in the switch network that would take some process of elimination to determine where.

.... Thinkpads_User
0
 
LVL 93

Expert Comment

by:John Hurst
ID: 39743613
I assume from your question this used to work. Nonetheless, make sure (somehow) DHCP scope did not change and that you have enough DHCP addresses to hand out.

.... Thinkpads_User
0
 

Author Comment

by:Xeronimo
ID: 39743665
Hi,

Yes, all of this worked fine until an electric blackout recently ...  the DHCP scope is correct and it also has enough free addresses.

It seems though that one or more switches could be the problem, or part of it. I'm able to ping one server correctly that's very close to me (only one switch, let's call it switch A), but not servers further away. What's weird though is that I sometimes get a ping timeout on switch A as well, although much less ... only 1 in 10 or something like that. The others give me 1 timeout for each successful ping ...
0
Problems using Powershell and Active Directory?

Managing Active Directory does not always have to be complicated.  If you are spending more time trying instead of doing, then it's time to look at something else. For nearly 20 years, AD admins around the world have used one tool for day-to-day AD management: Hyena. Discover why

 
LVL 93

Expert Comment

by:John Hurst
ID: 39743671
So then given your further explanation above, you appear to have a network problem, and the power outage (or the surge on power back) may have damaged a switch. I have seen that before. So you need to get one or two new switches and begin replacing and testing suspect switches.

.... Thinkpads_User
0
 
LVL 36

Expert Comment

by:Mahesh
ID: 39743919
This is definitely switch problem (malfunctioning).
You can reboot the switch (probably rebuild its configuration) where DHCP server is connected and test other computers on the same switch
Post switch reboot, the client computers on the same switch should get DHCP lease hopefully

Mahesh
0
 
LVL 38

Expert Comment

by:ChiefIT
ID: 39745625
Make sure the duplex settings on the switches and routers are not mismatched. Use Auto negotiate.

Your DHCP problem may be a different problem. It might stem from having a rogue DHCP server on the network. Use your servers for DHCP and make sure the switches/routers are not providing DHCP. There is a reason for the servers.
0
 

Accepted Solution

by:
Xeronimo earned 0 total points
ID: 39745842
Ok, I've finally found the problem ... for some reason the link aggregation didn't work correctly anymore and was creating a loop on the switch, thus flooding the network with broadcasts.

I've corrected this and now everything works fine again, including the DHCP!
0
 

Author Closing Comment

by:Xeronimo
ID: 39755811
I solved it myself
0

Featured Post

NAS Cloud Backup Strategies

This article explains backup scenarios when using network storage. We review the so-called “3-2-1 strategy” and summarize the methods you can use to send NAS data to the cloud

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
DNS issue with resolving request 14 88
windows 10 versions 3 36
Creating a Vendor Admin user 23 55
ICACLS "No mapping between account names and security IDs was done" 12 67
Possible fixes for Windows 7 and Windows Server 2008 updating problem. Solutions mentioned are from Microsoft themselves. I started a case with them from our Microsoft Silver Partner option to open a case and get direct support from Microsoft. If s…
While rebooting windows server 2003 server , it's showing "active directory rebuilding indices please wait" at startup. It took a little while for this process to complete and once we logged on not all the services were started so another reboot is …
This tutorial will give a an overview on how to deploy remote agents in Backup Exec 2012 to new servers. Click on the Backup Exec button in the upper left corner. From here, are global settings for the application such as connecting to a remote Back…
This video shows how to use Hyena, from SystemTools Software, to bulk import 100 user accounts from an external text file. View in 1080p for best video quality.

803 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question