Content

| 6.2 |  | Implementing Router Redundancy in a Switched Network |
| 6.2.7 |  | Server Load Balancing (SLB) |

SLB is an IOS-based solution defining a virtual server that represents a group of real servers in a server farm. This environment connects clients to the IP address of a single virtual server. The virtual server IP address is configured as a loopback address, or secondary IP address, on each of the real servers. When a client initiates a connection to the virtual server, the SLB function chooses a real server for the connection based on a load balancing algorithm. The network gains scalability and availability when virtual servers represent server farms. The addition of new servers and the removal or failure of existing servers can occur at any time without affecting the availability of the virtual server.

Supported Platforms

- Catalyst 6000 Series
- Cisco 7200 Series

Troubleshooting SLB
To obtain and display runtime information when monitoring and maintaining IOS SLB, use the following commands in the EXEC mode:

- show ip slb conns [vserver virtserver-name] [client ip-address] [detail] – Displays all connections handled by IOS SLB, or, optionally, only those connections associated with a particular virtual server or client
- show ip slb dfp [agent ip_addr port] [detail] [weights] – Displays information about DFP and DFP agents, and about the weights assigned to real servers.
- show ip slb reals [vserver virtserver-name] [detail] – Displays information about the real servers defined to IOS SLB.
- show ip slb serverfarms [name serverfarm-name] [detail] – Displays information about the server farms defined to IOS SLB.
- show ip slb stats – Displays IOS SLB statistics.
- show ip slb sticky [client ip-address] – Displays information about the sticky connections defined to IOS SLB.
- show ip slb vservers [name virtserver-name] [detail] – Displays information about the virtual servers defined to IOS SLB.

Refer to Figure for debug commands related to the IOS SLB feature.