Chapter 20 Firewall

20.5 Services Screen

If an outside user attempts to probe an unsupported port on your Router, an ICMP response packet is automatically returned. This allows the outside user to know the Router exists. Use this screen to prevent the ICMP response packet from being sent. This keeps outsiders from discovering your Router when unsupported ports are probed.

You can also use this screen to enable service blocking, enter/delete/modify the services you want to block and the date/time you want to block them.

Click Security > Firewall > Services. The screen appears as shown next.Figure 109 Security > Firewall > Services

The following table describes the labels in this screen.

Table 70 Security > Firewall > Services

LABEL

DESCRIPTION

ICMP

Internet Control Message Protocol is a message control and error-reporting protocol

 

between a host server and a gateway to the Internet. ICMP uses Internet Protocol (IP)

 

datagrams, but the messages are processed by the TCP/IP software and directly apparent

 

to the application user.

 

 

Respond to

The Router will not respond to any incoming Ping requests when Disable is selected. Select

Ping on

LAN to reply to incoming LAN Ping requests. Select WAN to reply to incoming WAN Ping

 

requests. Otherwise select LAN & WAN to reply to all incoming LAN and WAN Ping

 

requests.

 

 

Apply

Click Apply to save the settings.

 

 

 

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NBG-419N v2 User’s Guide