Mar 27, 2026 - For details about updated CVE-2025-53521 (BIG-IP APM vulnerability), refer to K000156741.

Forum Discussion

titankapo_33333's avatar
titankapo_33333
Icon for Nimbostratus rankNimbostratus
Sep 14, 2017

Block a DoS attack (TCP flag and/or UDP flood) with an iRule

Dear community,   I need to set up a new irule for basically mitigate a DoS attack. Specifically should work in case of TCP Flag Attacks ( SYN, ACK, FIN and RST) . Could someone help me with this?...
application delivery
irules
LTM
security
Faruk_AYDIN's avatar
Faruk_AYDIN
Icon for Altostratus rankAltostratus
Sep 25, 2017

Hi Guy,

You can have a look at TCP/IP flags and options, If you use the packet filters (
Network > Packet Filters
). Event name is 
FLOW_INIT
. Link is here. Then use DATAGRAM commands to access the flags and options. Its link is here