Monitor Options for an Interface
An interface can monitor objects for one or more of the following events.
Each of these events by itself or in combination can cause the state of
the monitoring interface to change from up to down or from down to up:
Physical disconnection/reconnection –
All physical interfaces on a device monitor the state of their physical
connection to other network devices (Layer 2 path monitoring). When an
interface is connected to and has established a link with another network
device, its state is physically up and all routes that use that interface
are active.
IP tracking failure/success –
Layer 3 path monitoring, or IP tracking, sends ICMP
requests on a specified interface to monitor up to four IP addresses at
user-determined intervals and then checks to see if the targets respond.
If the targets do not respond after a specified number of consecutive
failed attempts, the device can deactivate the routes associated with
the interface, even though the physical link still remains active. (The
interface must remain active to continue its effort to elicit a response
from its ICMP
requests.)
When the tracking of an IP address fails, the device compares the weight
assigned to the tracked IP address with the failure threshold for tracked
objects.
If the failure threshold for tracked objects has been exceeded, the device
then compares the weight for tracked objects with the monitored object
failure threshold.
If the monitored object failure threshold has been exceeded, the monitoring
interface changes its state, usually from up to down. Optionally, you
can also configure the monitoring interface to change its state from down
to up.
Failure/Success of a monitored interface –
An interface can monitor the physical and logical state of one or more
other interfaces and then take action based on observed changes. When
a monitored interface changes state, the device compares the weight assigned
to the monitored interface with the failure threshold for interface monitoring.
If the failure threshold has been exceeded, the monitoring interface changes
its state, usually from up to down. Optionally, you can configure the
monitoring interface to change its state from down to up.
Failure/Success of a monitored security
zone –
An interface can monitor all the interfaces in a security zone—in any
security zone other than its own. For an entire security zone to fail,
every interface bound to that zone must fail. As long as one interface
bound to a monitored zone is up, the device considers the entire zone
to be up. When a monitored zone changes state, the device compares the
weight assigned to the monitored zone with the failure threshold.
If the weight of the failed zone exceeds the failure threshold, the monitoring
interface changes its state, usually from up to down. Optionally, you
can also configure the monitoring interface to change its state from down
to up.
On this page you can set global options that apply to IP tracking and
to interface monitoring.
You can also link to the configuration pages to set the following monitored
objects:
IP Tracking To add addresses for IP tracking, click Monitor Track IP ADD.
Then configure the fields on the IP tracking configuration page. (See
.)
After you add a tracked IP address, you can see its settings in the Track
IP table. The Track IP table lists all configured tracked IP addresses
and the following information about each one:
IP Address: Identifies the tracked IP address.
Interval (sec): Indicates the interval of
time between ping requests.
Threshold: Indicates the number of consecutive
failures to elicit a ping response from a specific IP address required
to be considered a failed attempt.
Interface: Identifies the interface from
which the ping request is sent.
Weight: Indicates the weight of the IP address.
Method: Indicates that the device uses ping
requests to poll the remote device.
Configure: Click Edit to modify the existing Track IP entry, or click Remove to
delete it from the system.
Interface Monitoring To enable interface monitoring for specific interfaces,
click Monitor Interface Edit Interface. Then configure the fields on .
After you finish, you see a table displaying each monitored interface
and the weight that you assigned it.
Zone Monitoring To enable zone monitoring for specific zones,
click Monitor Zone Edit zone. Then configure the fields on .
After you finish, you see a table displaying
each monitored zone and the weight that you assigned it.