ADX Health Check

By default, when a real-server is created, the ADX will perform the following checks:

  • Layer 2 ARP
  • Layer 3 ICMP Ping

After the real-server is attached to the virtual-server using the bind command, the ADX will perform Layer 4 or Layer 7 checks based on the configuration.

It is essential to make sure that there is nothing blocking L2  or L3 checks between the ADX and the Server like a Firewall.

As there are multiple health checks for Brocade ADX, it is better to limit these checks to specific health checks to prevent any issues.

For example, when a real-server is created and “port http” configured,

port http url “HEAD /” is automatically added. Using “port http l4-check-only” will limit the health-check to Layer 4 health check instead of the Layer 7 checks. By default, for L7 “HEAD /” will mark the real-server as UP, if the response status code is 200-299, 401. This can be limited by using the command:

port http status-code 200 200

The above command will mark the real-server’s HTTP port UP, only if the response status-code is 200.

It is also essential to remember that the ADX will perform the L4 & L7 checks only once – when the real-server is bound to the virtual-server. If you require periodic checks, you would have to utilize the following command:

port http keepalive

The above command tells the ADX to keep checking the real-server’s port periodically instead of checking it only once.

A simple real-server would look like this for L4 Health-Check:

server real-server RS1

port http

port http keepalive

port http l4-check-only

port http url “HEAD /”


ADX Health Check


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