Basic concepts - useful for the certification

Provisioning levels

• nominal: what's needed, additional as needed
• minimum: what's needed, no additional resources
• dedicated: take everything, one module only

Elements

• node = ip addres of physical device
• pool member = node + service port
• pool = group of related pool members for load balancing
• virtual server = web listerner (often associated with a pool)

Processing order

1. Existing connection in conn table
2. Packet filter rule
3. Virtual Server
4. SNAT
5. NAT
6. SelfIP (check lockdown)
7. Drop

Types of Virtual Server

• Standard Virtual Server
• Forwarding IP
• Forwarding L2
• Performance HTTP
• Performance L4
• DHCP Relay

Virtual Address Status

• green circle - enabled
• yellow triangle - unavailable (conn limit)
• red diamond - offline due associated object
• black circle - disabled
• blue square - unknown (no monitors associated)

Pool Status

• green circle - any pool member available
• yellow triangle - no pool member available (conn limit)
• red diamond - offline due monitor
• black circle - disabled
• blue square - unknown (no monitors associated or unreachable)

Pool Member Status

• green circle - enabled
• yellow triangle - unavailable (conn limit)
• red diamond - unavailable (pool/node down)
• black circle - disabled (monitor detects up)
• black diamond - disabled
• blue square - unknown (no monitors associated or unreachable)

Pool member disabled still process persistent/active connections (but not when Down)

Pool member Forced Offline no new connections (just active)

Virtual Server disabled still process persistent/active connections