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

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340 Preventing attacks
Protecting your network resources from virus infections
4
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 .
5
To apply these settings, create a rule and enable the appropriate actions on the Antivirus tab.
Related information
For further information related to this topic, see the following:
■
“Antivirus—Configuration tab” on page 630
■
“Adding antivirus protection to a rule” on page 347
Avoiding potential session time-out errors
When a user attempts to download an extremely large or complex file from the Internet, a period of
time elapses while antivirus scanning takes place. During this time, the browser (and the user) receives
no feedback regarding the progress of the download. Without feedback, the user might try to click the
browser Refresh button several times even though the download is working properly. In some
instances, the browser can time out waiting for the scan to complete.
The security gateway data comforting feature avoids potential session time-out errors. When data
comforting is enabled, the requested file is sent (trickled) to the user in small amounts, at regular
intervals, until the scan is complete. When an infected file is detected while data comforting is enabled,
the connection is terminated.
Note: Data comforting is enabled automatically if you enable Dynamic Document Review (DDR) to scan
HTTP content. This prevents large file from causing the transfer to timeout.
See
“About Dynamic Document Review (DDR)” on page 309.
You should consider the limitations of data comforting before you use this feature.
Prerequisites
None.
To avoid potential session timeout errors
1 In the SGMI, in the left pane, under Policy, click Antivirus .
2 In the right pane, on the Configuration tab, select one of the following protocol subtabs:
■
POP3
■
HTTP
■
FTP
Due to the nature of the SMTP protocol, it does not require such comforting.
3 Under Comforting Settings, in the Wait time for proxy to start trickling data text box, type the
number (in seconds) that the scan process runs before data trickling begins.
4
In the Rate for proxy to trickle data text box, type how often (in seconds) to send a trickle of data to
the user.
5 Optionally, do one of the following:
■
To save your configuration now and activate later, on the File menu, click Save .
Alternatively, to activate the Save button on the toolbar, click on one of the other protocol
tabs, and then click
Save .