Specifications

Health monitors
BIG-IP® Reference Guide 4 - 157
11.12.11.20:80, 11.12.11.21:80, and 11.12.11.21:80 it would produce the
following instances, (which are in fact one instance associated with three
different nodes) as shown in Figure 4.74.
Using transparent mode
Sometimes it is necessary to ping the aliased destination through a
transparent node. Common examples are checking a router, or checking a
mail or FTP server through a firewall. For example, you might want to
check the router address 10.10.10.53:80 through a transparent firewall
10.10.10.101:80. To do this, you would specify 10.10.10.53:80 as the
monitor dest address (a node alias) and add the flag transparent:
b monitor http_trans ’{ use http dest 10.10.10.53:80 transparent }’
Then you would associate the monitor http_trans with the transparent node:
b node 10.10.10.101:80 monitor use http_trans
This causes the address 10.10.10 53:80 to be checked through
10.10.10.101:80. (In other words, the check of 10.10.10.53:80 is routed
through 10.10.10.101:80.) If the correct response is not received from
10.10.10.53:80, then 10.10.10.101:80 is marked down.
Note
Transparent mode applies only to the ECV monitors and to tcp_echo.
Using logical grouping
In the preceding examples, only one monitor has been associated with the
nodes. You may associate more than one monitor with a node or nodes by
joining them with the Boolean operator and. This creates a rule, and the
node is marked as down if the rule evaluates to false, that is, if not all the
checks are successful. The most common example is the use of an HTTP
monitor and an HTTPS monitor:
b node 11.12.11.20:80 monitor use my_http and my_https
+- NODE 11.12.11.20:80 ADDR UP
| |
| +- my_http
| 11.11.11.1:80 checking enabled
|
+- NODE 11.12.11.21:80 ADDR UP
| |
| +- my_http
| 11.11.11.1:80 checking enabled
|
+- NODE 11.12.11.22:80 ADDR UP
|
+- my_http
11.11.11.1:80 checking enabled
Figure 4.74 Node addresses aliased