Antivirus MIME Lists

Note: Juniper Networks supports external or internal antivirus (AV) on select devices. Your security device communicates with the external AV scan engine using Internet Content Adaptation Protocol (ICAP).

HTTP traffic is categorized into default predefined Multipurpose Internet Mail Extensions (MIME) types such as application/x-director, application/pdf, image, and so on. The security device uses such MIME types to decide which HTTP traffic must undergo AV scanning.

The table lists the following information on MIME types:

Name: Identifies the name of the MIME list.

Configuration: Click Edit to modify an existing MIME list. Click Remove to delete an existing MIME list.

Click New to create a new MIME list.

The maximum number of MIME lists for each VSYS (and root) is 9.

Default MIME List

To enhance performance, Juniper Networks security devices do not scan the MIME content types specified in the default MIME list, ns-skip-mime-list The default MIME list, ns-skip-mime-list includes the following predefined MIME types:

application/x-director
application/pdf
image/
video/
audio/
text/css
text/html. Because most HTTP entities are composed of these content types, HTTP scanning only applies to a small subset of HTTP entities, such as /zip and application/exe content types which are the types most likely to contain viruses.

To skip the configured MIME list from AV Scanning

Assign the MIME list to an AV profile:

Select the profile under Screening > Antivirus > profile.
Select HTTP.
Check the Skipmime Enable option.
Select the MIME list in the drop-down menu.