Tunnel Technology - AVM FRITZ!Box 6360 Cable Installation, Configuration And Operation

Tunnel Technology

Integrity
Integrity ensures that the data are not changed, recorded or
diverted during transmission.
The VPN tunnel fulfills these security requirements. The VPN
tunnel is implemented using a tunnel protocol.
5.3 Tunnel Technology
A tunnel is created by placing an IP packet to be transmitted
inside of an additional, new IP packet.
An IP packet is composed of the IP header and the user data.
The IP header contains the IP address of the destination and
the IP address of the sender.
The original packet is encrypted and authenticated before re-
packing.
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•
IP header
New
IP header
IP header
The IP addresses of the destination and the sender in
the new IP header are the public IP addresses of the two
VPN parties in the Internet. Only the new IP header can
be read in the Internet in clear text.
Thanks to the encryption and authentication, the origi-
nal packet remains concealed in the inside of the tunnel.
The IP addresses of the destination and sender in the IP
header of the original packet are private IP addresses in
the local network.
Data
Data
encrypted
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Original packet
Tunnel packet