Global URL Blocking (Via Local List)

HTTP > URL Access Control > Global URL Blocking | Via Local List

You can have IWSVA block certain Web pages, domains, and URLs from scanning. URL blocking is not policy based—it affects everyone in the organization.

One especially powerful use for URL blocking is to combat a sudden Internet threat such as a DoS attack or a new Internet worm. You can quickly create a rule to stop the threat from spreading or hijacking client machines.

• Enable URL blocking—Enable or disable URL blocking (click Save after enabling or disabling URL blocking).

• Match—Enter an exact Web site, a keyword or phrase, or a string of characters in the field, and then configure IWSVA with how to apply the match. URL blocking supports both ? and * wildcards.

• Web site—Limits the search to the string as a whole; used with one or more wildcards, this type of blocking can be especially useful for preventing access to an entire Web site. There is no need to include http:// or https:// in the URL (as it is automatically stripped).

• URL Keyword—Looks for any occurrence of the letters or numbers within a URL, and will match regardless of where the string is found (the string "sex" would be considered a match for "http://www.encyclopedia/content/sexton.htm" and the page blocked. Using wildcards with URL Keywords greatly increase the chance of false positives.

• String—Limits the search to the string as a whole; for example, to target a specific site, page, file, or other particular item.

• Note: For HTTPS decryption policies, the strings to match vary depending on whether you set IWSVA in the proxy or transparency modes.
  
  - In the proxy mode, IWSVA matches the domain names, not the full URL. Therefore, you only need to specify the domain names.
  
  - In the transparency mode (WCCP or bridge mode), IWSVA matches both the CommonNames and URLs. You must include these in the blocking list if you want to block an HTTPS site.  

• Import Block List and Exceptions—You can import an existing list of URLs that you want to block or exempt from filtering. For example, if you have a list of URLs from a third-party vendor, Web Manager, or related software program, or a list of sites you have compiled using a text editor, you can import the list rather than enter them one-by-one in the Match field. Imported lists must conform to a defined standard.