Forum Discussion

superuser_22978's avatar
superuser_22978
Icon for Nimbostratus rankNimbostratus
Jul 22, 2016

clients and servers are on the same network

Hi folks,

 

We have a load balancing scenario where the Client(10.10.10.10) and nodes (10.10.10.20 and 10.10.10.30) in the same network 10.10.10.0/24. Where the VIP is 20.20.20.20. I am using snat automap with the self ip as 10.10.10.5.

 

When the client initiates the connection to the vip I am seeing the traffic is hitting f5 in the tcpdump, also I am seeing the backend connection from the f5 self ip (10.10.10.5) to one of the nodes(say 10.10.10.20) and finally from the node(10.10.10.20) to the f5 self ip(10.10.10.5) which is perfectly fine.

 

Then I am also seeing some thing strange in the capture where the self ip (10.10.10.5) is directly talking to the client(10.10.10.10). This makes the connection from client unsuccessful all the time. Why is the self ip is trying to talk to client directly? as the client should get the response back from vip instead of self ip.

 

Any suggestions for this asymmetric packet flow. I have tried with snat pool with the ip in same subnet still the issue remains same. Am I missing any thing?

 

Thanks

 

2 Replies

  • these are tricky things to trouble shoot via a forum, if you have a F5 partner or can contact support about it and have them have a look that would probably be quicker.

     

    if you can't then i don't mind taking a stab. first can you show the packet capture (wireshark screenshot with the required columns shown) which shows the behaviour? point out your request from the client and the rest of the session.

     

    this is mainly to determine the traffic you see if related to the request, it could be other traffic which confuses things. what is the default gateway for the client and the nodes?

     

    have you tried with a virtual server with an IP in the range of the rest of the systems?

     

    have you modified the virtual server settings from the defaults?