Kemp Support, how can we help?

The latest application delivery knowledge and expertise at your fingertips.

Retransmissions and Dup Packets in TCP dump

 

Information

 

Summary:

 High number of retransmissions and duplicate packets when running a TCP dump.

Environment:

Product: LoadMaster

Version: Any

Platform: Any

Application: Any 

Question/Problem Description: 

When running a TCP dump on the LoadMaster there are numerous retransmissions and duplicate packets in WireShark.

Steps to Reproduce:  
Error Message:  
Defect Number:  
Enhancement Number:  
Cause:  
Resolution: 

When there are VLANs configured on the LoadMaster retransmissions are expected to appear in WireShark.

The LoadMaster receives the packet and needs to add the VLAN tag to the connection thus retransmitting this data.

As for duplicate packets, this can occur when the TCP dump filters on all interfaces which is also the expected behavior.

WireShark interprets that when captured on all interfaces packets are duplicates.

Workaround:  When running a packet capture filter on a specific interface to see the number of duplicate packets to decrease.
Notes: https://support.kemptechnologies.com/hc/en-us/articles/5143387464589-Packet-Trace-Guide

Comments