Solved

Bad Checksum errors

Posted on 2011-02-14
4
1,194 Views
Last Modified: 2012-06-27
Hi Guys,

What could be the issue of Bad checksum IP packets? I have collected some captures from Nortel switch stack and I am seeing lots of Bad Checksum and packets and retransmissions from one of the switches(speed less than 10KB) other switches looks fine ( Speed 20 MB). I know it's a fault switch but i wold like to know why it's causing Bad Checksum tcp packets.

Thanks in advance!
0
Comment
Question by:smartnet
  • 3
4 Comments
 
LVL 12

Expert Comment

by:jjmartineziii
ID: 34889639
more than likely, you have Checksum offloading to your nic. the nic calculates the checksum right before the wire and when you capture from the OS, you see 00000 as the checksum as it hasn't been calculated yet. turn off checksum offloading from your nic driver if you want to see the checksums.
0
 
LVL 12

Expert Comment

by:jjmartineziii
ID: 34889647
oops, i read wrong. how are you capturing? a span session?
0
 

Author Comment

by:smartnet
ID: 34889715
not span, directly form the PC that is having issue.
0
 
LVL 12

Accepted Solution

by:
jjmartineziii earned 500 total points
ID: 34889728
0

Featured Post

Zoho SalesIQ

Hassle-free live chat software re-imagined for business growth. 2 users, always free.

Question has a verified solution.

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

Suggested Solutions

Title # Comments Views Activity
VoIP and Data on single switch, with SonicWall 6 52
Communication between VMs on the same Vstwitch 7 62
Destination host unreachable 12 64
Cisco switch SVI 17 61
The worst thing when starting a new job is when the previous Network Administrator left behind no documentation. How do you get into the devices? If you've been in this situation or just accidently mistyped your password, this article will hopefully…
I see many questions here on Experts Exchange regarding switch port configurations and trunks. This article is meant for beginners in the subject to help to get basic knowledge about Virtual Local Area Network (VLAN (http://en.wikipedia.org/wiki/Vir…
Viewers will learn how to properly install and use Secure Shell (SSH) to work on projects or homework remotely. Download Secure Shell: Follow basic installation instructions: Open Secure Shell and use "Quick Connect" to enter credentials includi…
After creating this article (http://www.experts-exchange.com/articles/23699/Setup-Mikrotik-routers-with-OSPF.html), I decided to make a video (no audio) to show you how to configure the routers and run some trace routes and pings between the 7 sites…

932 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

Need Help in Real-Time?

Connect with top rated Experts

13 Experts available now in Live!

Get 1:1 Help Now