3Com S7902E, Configuration Manual

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No destination address needs to be configured for a 6to4 tunnel because the destination address
can automatically be obtained from the IPv4 address embedded in the 6to4 IPv6 address.
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If the addresses of the tunnel interfaces at the two ends of a tunnel are not in the same network
segment, a route to the peer must be configured so that the encapsulated packet can be forwarded
normally. You can configure static or dynamic routing. Automatic tunnels do not support dynamic
routing. You need to configure a route to the peer at both end of the tunnel. For the detailed
configuration, refer to Static Routing Configuration or other routing protocol configuration in the IP
Routing Volume .
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The automatic tunnel interfaces using the same encapsulation protocol cannot share the same
source IP address.
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When you configure a static route at one tunnel end, you need to configure a route to the
destination IPv6 address of the packet, instead of the IPv4 address of the tunnel destination, and
set the outbound interface to the tunnel interface at the local end or set the next-hop to the tunnel
interface at the peer end. The similar configuration needs to be performed at the other tunnel end.
6to4 Tunnel Configuration Example
Network requirements
As shown in Figure 1-9 , two 6to4 networks are connected to an IPv4 network through two 6to4 switches
(Switch A and Switch B) respectively. Configure a 6to4 tunnel to make Host A and Host B reachable to
each other.
To enable communication between 6to4 networks, you need to configure 6to4 addresses for 6to4
switches and hosts in the 6to4 networks.
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The IPv4 address of VLAN-interface 100 on Switch A is 2.1.1.1/24, and the corresponding 6to4
prefix is 2002:0201:0101::/48 after it is translated to an IPv6 address. Assign interface tunnel 0 to
subnet 2002:0201:0101::/64 and VLAN-interface 101 to subnet 2002:0201:0101:1::/64.
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The IPv4 address of VLAN-interface 100 on Switch B is 5.1.1.1/24, and the corresponding 6to4
prefix is 2002:0501:0101::/48 after it is translated to an IPv6 address. Assign interface tunnel 0 to
subnet 2002:0501:0101::/64 and VLAN-interface 101 to subnet 2002:0501:0101:1::/64.
Figure 1-9 Network diagram for a 6to4 tunnel
Vlan-int100
2.1.1.1/24 Vlan-int100
5.1.1.1/24
Vlan-int101
2002:0201:0101:1::1/64
Vlan-int101
2002:0501:0101:1::1/64
Switch A
Switch B
6to4 switch
Host A
2002:0201:0101:1::2/64
Host B
2002:0501:0101:1::2/64
6to4
Group 1
IPv4 netwok
6to4 switch
6to4
Group 2
Tunnel 0
2002:0201:0101::1/64 Tunnel 0
2002:0501:0101::1/64