topic Lots of FTP Fixup commands killing ASA CPU in Network Security

Lots of FTP Fixup commands killing ASA CPU

Martijn de Loos — Tue, 12 Mar 2019 06:29:40 GMT

Hi all,

On a regular interval we suffer from network downtime because our ASA 5510's CPU is going sky high (almost 100%). When I perform a sh perfmon command I see around 5000 FTP Fixup commands per second. Most likely this is the case. Is there any way to figure out where this traffic is coming from and block it?

Hello Martijn de Loos,You can

joseoroz — Tue, 25 Aug 2015 16:26:00 GMT

Hello Martijn de Loos,

You can run the command show conn | i :21

That will show you the connections on port 21

Also you can setup a capture.

cap test interface (interface name) tcp any any eq 21

to see the capture use the command show cap test and to remove it no cap test.

Kind regards,

Jose Orozco.