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

Forum Discussion

xiangyang_zhang's avatar
xiangyang_zhang
Icon for Nimbostratus rankNimbostratus
Jan 07, 2007

Manipulate TCP header

 

Due to the existing bug, the RST from client always causes trouble to server. Then I would like to block RST in BIGIP. However, I cannot find any iRule commands of manipluating TCP header. Any workaround ?

 

 

 

Thanks in advance !

 

XY zhang

3 Replies

  • hoolio's avatar
    hoolio
    Icon for Cirrostratus rankCirrostratus
    Jan 08, 2007
    There aren't any existing functions to get or change TCP flags. Here are a couple of related posts:

     

     

    Can I capture TCP Reset in iRules?

     

    Click here

     

     

    Capturing TCP resets (part deux)

     

    Click here

     

     

    Aaron
  • hoolio's avatar
    hoolio
    Icon for Cirrostratus rankCirrostratus
    Jan 08, 2007
    By the way, I suppose in theory you could do this manually by collecting the TCP packet and using binary scan to get/change the data by offsets. Paul posted a good example of using binary scan to drop specific packets (Click here)

     

     

    Aaron
  • xiangyang_zhang's avatar
    xiangyang_zhang
    Icon for Nimbostratus rankNimbostratus
    Jan 08, 2007
    Many thanks for information. It seems Paul post is talking about processing TCP load too.

     

     

    XY Zhang