LB VIP Is Not Responding to Syn Packet from Client

[RAQS]

Hi Team,

Hope all of you are doing good. I have below issue :-
We have pool of clients (set of proxy server, 1.1.1.1 - 1.1.1.6) , F5 is getting traffic from all Client IP and responding back, except for IP 1.1.1.5.

From 1.1.1.5, traffic is getting initiated but its not reaching F5. We can see traffic generated from Client reaeching to firewall and then switch but not seeing same time at F5.

Sniffer at firewall says that F5 is not responding for syn packet, but how F5 will reply if it is not seeing SYN packet?

Please help to look into this from F5 perspective.

Regards,

RAQS

[RAQS]

Hi Team,

Please help me on above request.

Regards,

RAQS

[RAQS]

Any help team.

[AubreyKingF5]

Sorry so late on this one! Not sure how I missed it, but I got it now.

Are you routed or SNAT? If routed, is the BIG-IP the default gateway?

What does a tcpdump say on the BIG-IP? So.. 'tcpdump -nei 0.0 src 1.1.1.5' or something like that.