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Forum Discussion

mwitt_65218's avatar
mwitt_65218
Icon for Nimbostratus rankNimbostratus
Aug 28, 2009

truncation/request length exceeds defined buffer size

Greetings,     I was wondering if anybody might have any thoughts about something.     The policy for a web app is in blocking mode, but the BLOCK box for Request Length Exceeds ...
app sec
BIG-IP Access Policy Manager (APM)
security
hoolio's avatar
hoolio
Icon for Cirrostratus rankCirrostratus
Aug 28, 2009
Hi,

 

 

As far as I'm aware, ASM should never modify the request payload. I believe the truncated flag just indicates that ASM did not log the full request as it was larger than some configured limit. If you put the policy in blocking mode and the request triggers a violation with blocking enabled, ASM would take the blocking action.

 

 

I think the default max request size is set to 10Mib per the long_request_buffer_size internal parameter (set under 'Application Security | Options | Advanced Configuration'. You could extend this max size or disable the check entirely by modifying the blocking mask and disabling blocking on the Request Length Exceeds Defined Buffer Size check.

 

 

Aaron