Hi, I have build a new application behind our hardware load balancer, since we need the 'sticky session' feather that our LB couldn't offer.So I put two nginx as a soft LB behind the hardware LB(that round-robin to nginx). Then I found the two nginx always hash the same client IP to different backend server. it's weird if I understood right about the ip_hash that using crc32 hashing the IP addreby kaktos - Nginx Mailing List - English