Members are the actual IP addresses that will receive traffic from the load balancer. Each
  member must have a unique combination of IP address and port.
  The Available Instances table contains existing compute instances that can be added as members
  of the pool. Use the "Add external member" button to add a member not found in the Available
  Instances table.
  IP address:
  
  The IP address of the member to receive traffic from the load balancer. Must be a well-formed
  IPv4 or IPv6 address.
  
  Subnet:
  
  The network which contains the IP address of the member.
  
  Port:
  
  The port on which the member listens for traffic. Must be a number from 1 to 65535.
  
  Weight:
  
  The weight of a member determines the portion of requests or connections it services compared
  to the other members of the pool. A value of 0 means the member does not receive new connections
  but continues to service existing connections. A higher weight means it will receive more
  traffic. Must be a number from 0 to 256.
  
  Monitor Address:
  
  An alternate IP address used for health monitoring a backend member.
  Default is null which monitors the member address.
  
  Monitor Port:
  
  An alternate protocol port used for health monitoring a backend member.
  Default is null which monitors the member protocol port.
  
  Backup:
  
  Is the member a backup? Backup members only receive traffic when all
  non-backup members are down.