Brocade Virtual ADX Server Load Balancing Guide (Supporting ADX v03.1.00) - Manual (Page 176)

160 Brocade Virtual ADX Server Load Balancing Guide
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Layer 3 health checks
4
Table 13 summarizes the Layer 3 health checks.
Disabling Layer 3 health checks
By default, when you add a real server configuration to the Brocade Virtual ADX, the Brocade
Virtual ADX uses a Layer 3 health check (IP ping) to determine the server’s reachability. If the real
server responds to the ping, the Brocade Virtual ADX changes the server’s state to ACTIVE and
begins using the server for client requests.
You can globally disable the Layer 3 health check for local servers or remote servers. You also can
disable the Layer 3 health check on individual real servers. When you disable the Layer 3 health
check, the Brocade Virtual ADX sends an ARP request for the default gateway and makes the
server’s state ACTIVE for as long as the ARP entry remains in the Brocade Virtual ADX’s ARP cache.
To globally disable the Layer 3 health check for all local real servers, enter the following command.
Virtual ADX(config)#server no-real-l3-check
Syntax: [no] server no-real-l3-check
To globally disable Layer 3 health check for all remote real servers or of IP addresses learned
through GSLB, enter the following command.
Virtual ADX(config)#server no-remote-l3-check
Syntax: [no] server no-remote-l3-check
NOTE
The server no-remote-l3-check command also disables Layer3 health checks of IP addresses
learned through GSLB.
To disable the Layer 3 health check on an individual real server, enter the following command.
Virtual ADX(config-rs-R1)#no-l3-check
Syntax: [no] no-l3-check
This command applies to local real servers and remote real servers.
TABLE 13 Summary of Layer 3 health checks
Type Description When performed
ARP request A standard IP ARP request for the server’s MAC
address, which the Brocade Virtual ADX adds to its
ARP table.
•
When you configure a real server
IP ping A standard ICMP-based IP ping.
•
When you configure a real server
•
If the ARP entry ages out
•
If the time between the last packet
sent to the server and the last packet
received from the server increases