Alcatel-Lucent 6850-48 Guia De Rede
Tunneling
Configuring IP
page 24-34
OmniSwitch AOS Release 6 Network Configuration Guide
September 2009
IP Encapsulation within IP
IPIP tunneling is a method by which an IP packet is encapsulated within another IP packet. The Source
Address and Destination Address of the outer IP header identifies the endpoints of tunnel. Whereas Source
Address and Destination Address of the inner IP header identifies the original sender and recipient of the
packet, respectively.
Address and Destination Address of the outer IP header identifies the endpoints of tunnel. Whereas Source
Address and Destination Address of the inner IP header identifies the original sender and recipient of the
packet, respectively.
Consider the following when configuring the IPIP tunnel interfaces:
• A switch can support up to 127 IPIP tunnel interfaces.
• IPIP tunnel interfaces are included in the maximum number of IP interfaces that are supported on the
switch.
Tunneling operation
The diagram below illustrates how packets are forwarded over the tunnel.
In the above diagram, IP packets flowing from the private IP network 50.0.0.0 to the private IP network
40.0.0.0 are encapsulated by the tunneling protocol at switch A and forwarded to switch B. Intermediate
switches route the packets using addresses in the delivery protocol header. Switch B extracts the original
payload and routes it to the appropriate destination in the 40.0.0.0 network.
40.0.0.0 are encapsulated by the tunneling protocol at switch A and forwarded to switch B. Intermediate
switches route the packets using addresses in the delivery protocol header. Switch B extracts the original
payload and routes it to the appropriate destination in the 40.0.0.0 network.
The tunnel interface is identified as being up when all of the following are satisfied:
• Both source and destination addresses are assigned.
• The source address of the tunnel is one of the switch's IP interface addresses that is
either a VLAN or
Loopback0 interface.
Private IP Network
50.0.0.0
Private IP Network
40.0.0.0
Switch A
Switch B
IP Host
50.0.0.1
IP Host
IP Host
40.0.0.1
40.0.0.1
IP Host
24.24.24.2
24.24.24.1
Tunnel Endpoint
23.23.23.1
Tunnel Endpoint
155.2.2.2
Outer IP Header : 23.23.23.1, 155.2.2.2
Inner IP Header : 50.0.0.1, 40.0.0.1