[Info] Miscellaneous Attack Detection Settings

[Pfipps]

Is “packet checksum verification” the same as “stateful packet inspection”? If there is a difference, what is it?

[Opus_Dei]

No they are not the same.
Checksum might slow your conection but try it if you want

@svein post:4

A checksum is a mathematical way of controlling that the network packet is intact, and unmodified.

All (non-idiotic) network protocols include checksumming on layers 2 and 3. Most modern network adapters that do layer-3 decoding in the NIC, does the checksumming there, no need to worry.

The two reasons for enabling checksumming, would be:

a) to root out connectivity problems, i.e. packets that are damaged during transit from one host to another. The packet would simply be dropped (and thus seen as packetloss, and be retransmitted)
b) To be somewhat resistent to certain monkey-in-the-middle attacks, where a hostile machine between you and the remote host modifies data in the packet during transit, and thus inject “hostile” data.

If you are using a decent NIC, and are using good software, this shouldn’t really be necessary to enable.

//Svein

What is Stateful Packet Inspection? When an IP packet arrives at the firewall from the Internet, the firewall must decide if it should be forwarded to the internal network. In order to accomplish this the firewall "looks" to see what connections have been opened from the inside of the network to the Internet. If there is a connection open that applies to the packet that has arrived from the Internet then it will be allowed through, otherwise it will be rejected.

Hope this helps

OD