User guide

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eration ﬁrewall technologies inspect between 1 and 3 layers of the 7 layer

model, while our SMLI engine inspects layers 2 through 7.

-----N-----

NAK. Negative acknowledgment. See ACK.

Name. The Name parameter refers to the name of the conﬁgured tunnel.

This is mainly used as an identiﬁer for the administrator. The Name parame-

ter is an ASCII and is limited to 31 characters. The tunnel name is the only

IPSec parameter that does not need to match the peer gateway.

NCP. Network Control Protocol.

Negotiation Method. This parameter refers to the method used during the

Phase I key exchange, or IKE process. SafeHarbour supports Main or

Aggressive Mode. Main mode requires 3 two-way message exchanges while

Aggressive mode only requires 3 total message exchanges.

null modem. Cable or connection device used to connect two computing

devices directly rather than over a network.

-----P-----

packet. Logical grouping of information that includes a header and data.

Compare frame, datagram.

PAP. Password Authentication Protocol. Security protocol within the PPP pro-

tocol suite that prevents unauthorized access to network services. See RFC

1334 for PAP speciﬁcations. Compare CHAP.

parity. Method of checking the integrity of each character received over a

communication channel.

Peer External IP Address. The Peer External IP Address is the public, or

routable IP address of the remote gateway or VPN server you are establish-

ing the tunnel with.