Example 3.24. 6in4 Tunnel Configuration
In this example, a 6in4 Tunnel object will be configured to connect with a remote tunnel server
across the public Internet.
It is assumed that a number of address objects have already been configured in the
NetDefendOS address book. These have the names local_endpoint_ip6 for the local inner IPv6
endpoint of the tunnel and tunnel_server_ip4 for the IPv4 address of the tunnel server.
Command-Line Interface
gw-world:/> add Interface IP6in4Tunnel my_6in4_tunnel
IP=local_endpoint_ip6
Network=all-nets6
RemoteEnpoint=tunnel_server_ip4
Web Interface
1. Go to: Network > Interfaces and VPN > 6in4 > Add > 6in4 Tunnel
2. Enter the following:
• Name: my_6in4_tunnel
• IP Address: local_endpoint_ip6
• Remote Network: all-nets6
• Remote Endpoint: tunnel_server_ip4
3. Click OK
Routing Table Usage with 6in4 Tunnels
By default, the lookup of the IPv4 remote endpoint is done in the NetDefendOS main routing
table. This can be changed to be a specific routing table. The route for the Remote Network
property of the tunnel is also added, by default, to all routing tables including the main table.
This can also be changed so that the addition is made to a specific routing table.
MTU resizing
The MTU used by the protected IPv6 clients should not be too large since this will result in
excessive fragmentation during the tunneling process and thereby introduce unnecessary
overhead. There are two ways that the IPv6 clients behind a firewall can have their MTU value
adjusted:
• If the Pass returned ICMP error messages from destination property is enabled for the
Service objects used by the IP rules or IP policies controlling traffic flow, the IPv6 hosts will
initially take on the default MTU property of the 6in4 Tunnel object. By default this is 1280
which is the minimum value for IPv6. If other downstream network equipment requires a
different MTU, this can also be communicated via ICMP messages.
• A NetDefendOS Router Advertisement object can be configured on the interface connected to
Chapter 3: Fundamentals
211
To Next Page
Loading...
