4. Load Balancing Terminology
- The devices represented by the IP address of Pool Member are called Nodes. Hence Node has only IP address & may represent in many pool members. ( IP Address )
Ø Pool Members
- A pool member is an IP address and service port combination that is hosted by physical server.
- A single server can host any number of pool member because the different service ports may run various services. ( IP Address:Port )
- A pool is a group of pool member and is identified by name. In addition to pools member, pools also have their own load balancing method, monitors and other feature.
Ø Virtual Servers
- A virtual Server is a combination of Virtual IP address & service Port
- Virtual Server is mapped with multiple actual server or pools.
- Virtual Server will perform multiple functions like: Server availability Load Balancing, translation of virtual IP address to actual IP address, Translate virtual server service ports to actual server service ports.
- By default translation of address & ports are enabled in virtual server.
Ø Packet Flow through BIG IP :
ü Client initiate request to BIG IP Virtual Server IP address & Service Port
ü BIP IP translate VIP to actual IP address
ü Server will see Client IP address as a source & own IP address in destination
ü Server will reply to that session & BIG IP will translate back server actual IP to VIP address