User manual

Chapter 4 - Layer 3 Command Set - IP Networking Tun Command (Tunnels Building)
Alvarion BreezeNET B130/B300 GigE 108 Operational User Manual
There are several approaches to build tunnels. One of these, IP into IP
Encapsulation (described in RFC 2003), is implemented in OS WANFleX. This
technology is used, for example, in Cisco Systems routers, and is a subset of the
IPSEC protocol supported by several operating systems.
Within this approach, tunnels are implemented as point-to-point (P2P) links
between two endpoint devices. The whole data stream through such a link is
encapsulated into IP packets at one end of a link and is delivered to its opposite
end through the existing transport network.
Four parameters are necessary to configure a tunnel:
1 The internal IP-address of the local end of the P2P link.
2 The internal IP-address of the remote end of the P2P link.
3 Real source IP-address to be specified in the outgoing packets.
4 Real destination IP-address to be specified in the outgoing packets.
Internal IP-addresses of both ends of a P2P link are set using ifconfig command;
all other parameters are specified by the tun command (see example below).
Syntax:
tun N src ADDR dst ADDR [mtu N] [[-]df] | clear
Description:
Assigns the source (src) and destination (dst) real IP-addresses to a tunnel
specified by its logical number N which has been created by an ifconfig
command.
Figure 4-2: Tunnels Inside the Same Network