Secure Computing SG300 User Manual page 109

2. Assign unused alias IP addresses to the LAN interfaces at both ends of the
tunnel.
3. Create an IPSec tunnel between the alias IP addresses, using a prefix length for
each network of /32.
4. Create a GRE tunnel for which the Local Address is the local LAN IP address,
and the Remote Address is the remote LAN IP address.
5. Create bridges between the LAN interfaces and the GRE tunnel.
To bridge the local and remote LAN over IPSec:
1. Create an alias on the local LAN interface, and another alias on the remote LAN
interface.
2. Create an IPSec tunnel for which the Local Network is the local LAN IP address,
and the Remote Network is the remote LAN IP address, using a prefix length of
/32 for each network.
3. Create a GRE tunnel for which the Local Network is the local alias address, and
the Remote Network is the remote alias address.
4. Create a bridge between the LAN interface the the GRE tunnel at each end.
In this example we use a dummy alias network of 10.254.0.0 / 255.255.0.0 to bridge two
local networks, one at Brisbane and one at Slough. These steps must be repeated for
either end of the tunnel.
Note that the two locations are using the same subnet.
SnapGear unit in Brisbane
SnapGear unit in Slough
Network Setup
Internet address:
LAN address:
LAN alias:
LAN:
Internet address:
LAN address:
LAN alias:
LAN:
203.23.45.6
192.168.1.1
10.254.0.1
192.168.1.0 / 24
195.45.67.8
192.168.1.2
10.254.0.2
192.168.1.0 / 24
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