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Catalyst 6500 Series Switch Software Configuration Guide—Release 8.7
OL-8978-04
Chapter 54 Configuring ASLB
Configuring ASLB on the Switch
ASLB Configuration Guidelines
This section lists the usage guidelines and restrictions for configuring ASLB:
•
Routers, page 54-8
•
Servers, page 54-8
•
IP Addresses, page 54-9
•
Supervisor Engine, page 54-9
•
Backup LocalDirector Configuration (Optional), page 54-9
•
MSFC and Multilayer Switching, page 54-10
•
NetFlow Data Export, page 54-10
•
VLANs, page 54-10
•
Switch Port Configuration, page 54-10
For configuration examples, see the
“ASLB Configuration Example” section on page 54-18
. If you run
into problems during your configuration, see the
“Troubleshooting the ASLB Configuration” section on
page 54-25
.
Routers
The router configuration guidelines are as follows:
•
The router must be the default gateway for the servers that are being load balanced, and its MAC
address must be known.
•
Multiple routers must be on the same router VLAN. Specify all the participating router MAC
addresses by entering the
set lda mac router
command.
•
When ASLB is configured, a VLAN access control list (VACL) is created to redirect the TCP traffic
on the two VLANs to which the LocalDirector is connected; no security Cisco IOS access control
lists (ACLs) or VACLs can be configured on these VLANs.
Servers
The server configuration guidelines are as follows:
•
The servers must be either directly attached to the switch or within the same bridging domain as the
LocalDirector port in the server VLAN.
•
Configure the server default route as the aliased address of the router that is on the same subnet as
the real IP address of the server.
•
Configure the servers to ignore the ARP requests for the virtual-IP address. On some server
operating systems, you cannot disable the responses to the ARP requests on the alias (secondary) IP
addresses. Use the static ARP entries at the routers as a workaround for the servers that respond to
the ARP requests for the virtual-IP address.
Caution
To accelerate the client-to-server traffic, you must configure the servers to ignore the ARP requests for
the virtual-IP address. If you fail to do this step, traffic acceleration does not start, and fully redundant
topologies in your network take a long time to recover from a LocalDirector failure.