Symantec Security 5600 Series, Security 5400 Series,Clientless VPN 4400 Series, Administration Manual

Page: 303 / 861

302 Controlling traffic at the security gateway
Blocking inappropriate content with content filtering
5
On the Content Filtering tab, ensure that the HTTP check box is checked.
6 Under Select the protocols and settings to apply content filtering scanning, check Apply URL
pattern match restrictions .
7 Optionally, do one of the following:
■
To save your configuration now and activate later, on the toolbar, click Save .
■
To activate your configuration now, on the toolbar, click Activate .
When prompted to save your changes, click Yes .
Related information
For further information related to this topic, see the following:
■
“Content Filtering—Advanced Restrictions tab” on page 646
■
“Content Filtering Advanced Restrictions tab—URL Pattern dialog box” on page 647
■
“Adding content filtering protection to a rule” on page 316
Filtering by MIME type
You can create an allow list or a deny list (but not both) to control access to certain files based on
Multipurpose Internet Mail Extension (MIME) types. You can use this feature to allow or prevent the
downloading of certain usage formats (such as graphics files) or application types. MIME restrictions
apply globally to all HTTP-based services. MIME filtering is enabled when you check Apply MIME type
restrictions in the HTTP parameters for a rule that contains HTTP.
The HTTP proxy can restrict or permit access according to a list of MIME types. Each URL that is
received is scanned to determine its content type. If the content type matches a selected MIME type,
access is denied or allowed accordingly. When a particular MIME type should be denied based on the
configuration, the Web page downloads, but those components that match the blocked MIME type do
not download.
For additional information, including a list of common MIME types, see RFC 1521 at the Request For
Comments Web site:
http://www.rfc-editor.org/
Prerequisites
None.
Filter by MIME types
To fIlter traffic by a specific MIME type, you must do the following:
■
Specify the MIME type and whether it is allowed or denied.
■
Create a rule and apply the MIME type restriction.
To filter by MIME type
1 In the SGMI, in the left pane, under Policy, click Content Filtering .
2 In the right pane, on the Advanced Restrictions tab, under MIME types, in the Available list, select
the MIME type you want to restrict and click the right-arrow > button to add it to the Selected list.
3
To remove a MIME type from the Selected list, select the entry, and then click the left-arrow <
button.
The entry is moved to the Available list.
4
On the Advanced Restrictions tab, to add new MIME types to the Available list, do the following:
■
Under the MIME Types Available list, click Add .
■
In the MIME Type dialog box, in the MIME type text box, type the MIME type that you want to
add.