4.5.6 Running the Diagnostic Tools
The appliance offers a set of diagnostic tools that you can use to diagnose problems connecting
to remote websites. Before trying these tools, you should ensure that you have checked the
connection, using the Configuration > Group Policy > Policy Test page to confirm that access
to the site is allowed by the policy.
1. Enter the hostname, URL, or IP address of the site to which you want to check the connection.
If you are using
Send HTTP request
, you can specify the protocol (for example, HTTPS).
You can also specify a particular file.
Note:
Send HTTP request
will not retrieve the actual file, just the headers.
2. Select the diagnostic tool that you want to use from the drop-down list.
The options are Ping, Traceroute, DNS lookup, and Send HTTP request. The common uses
of these tools are:
■
Ping: Tests connectivity to a server or site.You can either use
ping
to check if the appliance
has the network access to contact a particular server, or—if you are confident that the
appliance has no access problems—you can use it to check whether a particular server is
actually up and running.
■
Traceroute: Identifies the "hops" the appliance has to go through to access a particular
destination. If the appliance is having trouble accessing a destination,
traceroute
would
show where the request is being routed and possibly identify the source of the problem (for
example, you might find that a request is being routed to an unexpected router that is unable
to handle the request).
■
DNS lookup: Checks which IP(s) a particular hostname resolves to. A site can be blocked
by its hostname or by its IP address. If a site is being blocked, but its hostname is set to
"Allow" in the Policy Tester, it may be blocked according to its IP address. Alternatively,
there may be a problem accessing a site because old or invalid DNS entries resolve to a
non-existent or invalid IP address.
■
Send HTTP request: Downloads the headers in response to an HTTP request. You can
use this option to determine if the destination site is responding incorrectly to the appliance
(the request would return an invalid HTTP header). This can help you troubleshoot a site
that is not working.
3. Click Run Test.
The results of the selected test are displayed in the Test results panel.