Manually Configuring your Modem-Router
Network attacks that deny access to a network device are called DoS attacks.
DoS attacks are aimed at devices and networks with a connection to the Internet. Their goal is not to steal information, but to disable a device or network so users no longer have access to network
resources.
The
Note: The firewall does not significantly affect system performance, so we advise enabling the prevention features to protect your network.
Parameter | Defaults | Description |
Enable SPI | Yes | The Intrusion Detection feature of the |
and Anti- |
| VoIP |
DoS firewall |
| of incoming traffic at the WAN port. |
protection |
| When the Stateful Packet Inspection |
|
| (SPI) feature is turned on, all incoming |
|
| packets are blocked except those |
|
| types marked with a check in the |
|
| Stateful Packet Inspection section at |
|
| the top of the screen. |
Manually Configuring your Modem-Router
Stateful Packet | This option allows you to select |
Inspection | different application types that are |
| using dynamic port numbers. If you |
| wish to use Stateful Packet Inspection |
| (SPI) for blocking packets, click on the |
| Yes radio button in the “Enable SPI and |
| |
| then check the inspection type that you |
| need, such as Packet Fragmentation, |
| TCP Connection, UDP Session, FTP |
| Service, H.323 Service, and TFTP |
| Service. It is called a “Stateful” packet |
| inspection because it examines the |
| contents of the packet to determine |
| the state of the communication; i.e., |
| it ensures that the stated destination |
| computer has previously requested the |
| current communication. This is a way |
| of ensuring that all communications are |
| initiated by the recipient computer and |
| are taking place only with sources that |
| are known and trusted from previous |
| interactions. In addition to being more |
| rigorous in their inspection of packets, |
| stateful inspection firewalls also |
| close off ports until a connection to |
| the specific port is requested. When |
| particular types of traffic are checked, |
| only the particular type of traffic |
| initiated from the internal LAN will be |
| allowed. For example, if the user only |
| checks FTP Service in the Stateful |
| Packet Inspection section, all incoming |
| traffic will be blocked except for FTP |
| connections initiated from the local |
| LAN. |
Discard Ping | Prevents a ping on the Modem- |
from WAN | Router’s WAN port from being routed |
Discard | to the network. |
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