Question: When starting nstrace with invalid filter expression, netscaler throws a warning message that filter is wrong but starts the nstrace without any filter.

For example if you use below filter when starting nstrace it will throw the warning message as shown below:

CONNECTION.DSTIP.ADD(10.70.165.79).ADD(10.70.165.80).ADD(10.70.165.81).ADD(10.70.165.82).ADD(10.70.165.240).ADD(10.70.165.241).ADD(10.70.165.242)

From GUI error is as below



From cli:
===

start nstrace -filter CONNECTION.DSTIP.ADD(10.70.165.79).ADD(10.70.165.80).ADD(10.70.165.81).ADD(10.70.165.82).ADD(10.70.165.240).ADD(10.70.165.241).ADD(10.70.165.242)
Warning: Invalid filter expression. nstrace will now start without filters


Answer: This is a design change from 10.5 and 11.0 onwards and is being done deliberately for the ease of use of customers.
 
Normally customers are not aware of the filters and expression used when starting nstrace and in most of the cases default (without the filters) is enough. So engineering team has deliberately added this behaviour with the Warning message which is self explanatory that it will remove the invalid filter and start the nstrace without any filter.

In previous releases like 10.1 when using a invalid filter, it will not throw any warning message and also will not start the nstrace.

> start nstrace -filter "CONNECTION.DSTIP.ADD(10.70.165.79).ADD(10.70.165.80).ADD(10.70.165.81).ADD(10.70.165.82).ADD(10.70.165.240).ADD(10.70.165.241).ADD(10.70.165.242)"
 Done

If you see above no warning message thrown from the 10.1 netscaler.