User`s manual

TC-6110 Linux User's Manual Managing Communications
3-30
Ethernet Bridging for Private Networks on the Same Subnet
Like the last example, this setup will link two subnets across the oopen Ethernet; however, these two subnets
will share addressing as if they were located on the same local subnet.
All of the clients on the two remote subnets are configured for a range of IP addresses that spans the same
subnet. When this configuration is moved to a public network, the external interfaces of the OpenVPN
machines must be configured for static IPs or connected to another device (such as a firewall or DSL box) that
uses a static address.
The configuration procedure for this setup is almost the same as for the previous example. The only difference
is that you will need to comment out the parameter up in the
/etc/openvpn/tap0-br.conf on each of the
gateways, OpenVPN A and OpenVPN B.
# point to the peer
remote 192.168.8.174
dev tap0
secret /etc/openvpn/secrouter.key
cipher DES-EDE3-CBC
auth MD5
tun-mtu 1500
tun-mtu-extra 64
ping 40
#up /etc/openvpn/tap0-br.sh
#comp-lzo
Routed IP Tunnels
Routed IP tunnels are used to route point-to-point IP traffic without broadcasts; the advantage of routed IP
tunnels is that they are slightly more efficient than bridged ethernet tunnels and easier to configure.
1. Host A represents the machine that belongs to the subnet served by the VPN server, OpenVPN A, and
Host B represents a machine that belongs to the subnet served by the VPN server, OpenVPN B. The two
remote subnets are configured for distinct ranges of private IP addresses on separate subnets.