Forum Discussion
Nishal_Rai
Cirrocumulus
CirrocumulusHow does F5 virtual server forwards request based on LTM policies to another virtual server
Hello Everyone, I just wanted to know how the forwarded virtual server (the request forwarded by one VS to another VS using either iRule or LTM policies) works in the context of a TCP in f5 big-ip?...
Nishal_RaiCirrocumulus
CirrocumulusHello Lucas_Thompson & zamroni777,
Thanks for the insight and information about the virtual server forwarding in f5 big-ip.
Regarding the zamroni777 - for your config, client doesn't create a second TCP connection to second VS.
I verified there is only a single TCP connection between the client and the destinated virtual server (192.168.180.129:80)
So about the statement, it's simply forwarding within the LTM, When viewed from the packet capture on the f5 big-ip with the host of virtual server ip - 192.168.180.129.
On the second SYN flagged as OUT, what does that mean where the source IP is the actual client and the destination is the virtual server with port 8080?
Does this mean f5 big-ip forwarded the whole TCP connection of the client (192.168.100.28) from the VS listening on port 80 to another VS listening on port 8080 (as per above conversation)?
If it is so then shouldn't the identification number of the packet be shared between the communication of the actual client and the f5 big-ip virtual server?
- Lucas_Thompson
Employee
re: Does this mean f5 big-ip forwarded the whole TCP connection of the client (192.168.100.28) from the VS listening on port 80 to another VS listening on port 8080 (as per above conversation)?
Essentially, yes, but keep in mind that there are essentially two halves of each flow because BIG-IP is a full-proxy. Packet data is serialized/deserialized between them. This article may help explain it:
https://community.f5.com/t5/technical-articles/the-full-proxy-data-center-architecture/ta-p/279637
