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

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Nom_55811's avatar
Nom_55811
Icon for Nimbostratus rankNimbostratus
Jun 20, 2010

Source Port Mangled down OSPF Tunnel

Hi Guys,     We're currently transitioning to using advanced routing and BGP/OSFP advertisement of VIPs, and an issue has come up which is confusing me to no end. I hope someone can point me in...
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Nom_55811's avatar
Nom_55811
Icon for Nimbostratus rankNimbostratus
Jun 21, 2010
I've just played with the Source Port settings and discovered the following:

 

Change - produces incrementing source ports starting from 2059 (may have been more before that, but that's the lowest in my tcpdump)

 

Preserve - Source port for DNS response is always 1025

 

Preserve Strict - No response packet received