OVERVIEW

This probe tests if your filtering webproxy is working properly. Drawing from a list of forbidden websites, it tries to establish a connection to each one of them and registers a 'loss' when it suceeeds.

If you want to test availability of a website, use the EchoPingHttp probe.

SYNOPSIS

*** Probes ***
+WebProxyFilter
forks = 5
maxsize = 2000
min_interval = 0.1
offset = 50%
step = 300
timeout = 15
useragent = SmokePing/2.x (WebProxyFilter Probe)
# The following variables can be overridden in each target section
deny_re = Access Prohibited
more_hosts = www.playboy.com, www.our-competition.com
pings = 5
timeout = 2
# [...]
*** Targets ***
probe = WebProxyFilter # if this should be the default probe
# [...]
+ mytarget
# probe = WebProxyFilter # if the default probe is something else
host = my.host
deny_re = Access Prohibited
more_hosts = www.playboy.com, www.our-competition.com
pings = 5
timeout = 2

DESCRIPTION

The probe uses the LWP::UserAgent module to retreive a series of wepages. It expects to get the firewalls 'site-prohibited' page. Any other response (or a real loss) gets logged as a loss and can be used to trigger an alarm.

The probe tries to be nice to the firewall and waits at least X seconds between starting filetransfers, where X is the value of the probe specific `min_interval' variable (1 by default).

Many variables can be specified either in the probe or in the target definition, the target-specific variable will override the prove-specific variable.

VARIABLES

Supported probe-specific variables:

forks

Run this many concurrent processes at maximum

Example value: 5

Default value: 5

maxsize

How much of the webpage should be retreived.

Default value: 2000

min_interval

The minimum interval between each starting GETs in seconds.

Example value: 0.1

Default value: 1

offset

If you run many probes concurrently you may want to prevent them from hitting your network all at the same time. Using the probe-specific offset parameter you can change the point in time when each probe will be run. Offset is specified in % of total interval, or alternatively as 'random', and the offset from the 'General' section is used if nothing is specified here. Note that this does NOT influence the rrds itself, it is just a matter of when data acqusition is initiated. (This variable is only applicable if the variable 'concurrentprobes' is set in the 'General' section.)

Example value: 50%

step

Duration of the base interval that this probe should use, if different from the one specified in the 'Database' section. Note that the step in the RRD files is fixed when they are originally generated, and if you change the step parameter afterwards, you'll have to delete the old RRD files or somehow convert them. (This variable is only applicable if the variable 'concurrentprobes' is set in the 'General' section.)

Example value: 300

timeout

How long a single 'ping' takes at maximum

Example value: 15

Default value: 5

useragent

The web browser we claim to be, just in case the FW is interested

Default value: SmokePing/2.x (WebProxyFilter Probe)

Supported target-specific variables:

deny_re

Regular expression, matching the 'deny' response from the firewall

Example value: Access Prohibited

more_hosts

A comma separated list of banned websites to test in addition to the one specified in the host variable. The websites will be tested one after the other in one round, this means that while normal probes do run the same test serveral times in a row, this one will alter the webpage with each round. The reason for this is, that eventhough we try to retreive remote webpages, the answer will come from the firewall everytime, so we kill two birds in one go. First we test the firewalls latency and second we make sure its filter works properly.

Example value: www.playboy.com, www.our-competition.com

pings

How many pings should be sent to each target, if different from the global value specified in the Database section. Note that the number of pings in the RRD files is fixed when they are originally generated, and if you change this parameter afterwards, you'll have to delete the old RRD files or somehow convert them.

Example value: 5

timeout

Timeout in seconds for the test complete.

Example value: 2

Default value: 2

AUTHORS

Tobias Oetiker <[email protected]> sponsored by Virtela