Netgear UTM25-100NAS ユーザーズマニュアル

Network and System Management

10-5

–

Web object blocking. You can block the following Web component types: embedded 
objects (ActiveX, Java, Flash), proxies, and cookies, and you can disable Java scripts. For 
more information, see 

–

Setting the size of Web files to be scanned. Scanning large Web files requires network 
resources and might slow down traffic. You can specify the maximum file size that is 
scanned, and if files that exceed the maximum size are skipped (which might compromise 
security) or blocked. For more information, see 

.

For these features (with the exception of Web object blocking and setting the size of files to be 
scanned), you can set schedules to specify when Web content is filtered (see 

) and configure exceptions for groups (see 

).

If you want to reduce outgoing traffic by preventing Internet access by certain PCs on the LAN, 
you can use the source MAC filtering feature to drop the traffic received from the PCs with the 
specified MAC addresses. By default, this feature is disabled; all traffic received from PCs with 
any MAC address is allowed. See 

 for the 

procedure on how to use this feature.

The following features of the UTM tend to increase the traffic load on the WAN-side:

•

LAN WAN inbound rules (also referred to as port forwarding)

•

DMZ WAN inbound rules (also referred to as port forwarding)

•

Port triggering

•

Enabling the DMZ port

•

Configuring Exposed hosts

•

Configuring VPN tunnels

The LAN WAN Rules screen and the DMZ WAN Rules screen list all existing rules for inbound 
traffic (from WAN to LAN and from WAN to the DMZ). If you have not defined any rules, only 
the default rule is listed. The default rule blocks all access from outside except responses to 
requests from the LAN side. Any inbound rule that you create allows additional incoming traffic 
and therefore increases the traffic load on the WAN side.