Configuring IP
Tunneling
OmniSwitch AOS Release 7 Network Configuration Guide
June 2013
page 15-33
Displaying UDP Information
UDP is a secondary transport-layer protocol that uses IP for delivery. UDP is not connection-oriented and
does not provide reliable end-to-end delivery of datagrams. Few applications can safely use UDP to send
datagrams that do not require the extra overhead added by TCP. Use the
command to
display UDP statistics. Use the
command to display UDP port information.
Tunneling
Tunneling is a mechanism that can encapsulate a wide variety of protocol packet types and route them
through the configured tunnels. Tunneling is used to create a virtual point-to-point link between routers at
remote points in a network. This feature supports the creation, administration, and deletion of IP
interfaces whose underlying virtual device is a tunnel. The Alcatel-Lucent implementation provides
support for two tunneling protocols: Generic Routing Encapsulation (GRE) and IP encapsulation within
IP(IPIP).
Generic Routing Encapsulation
GRE encapsulates a packet to be carried over the GRE tunnel with a GRE header. The resulting packet is
then encapsulated with an outer header by the delivery protocol and forwarded to the other end of the GRE
tunnel. The destination IP address field in the outer header of the GRE packet contains the IP address of
the router at the remote end of the tunnel. The router at the receiving end of the GRE tunnel extracts the
original payload and routes it to the destination address specified in the IP header of the payload.
Note.
A switch can support up to 127 GRE tunnel interfaces.
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.
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.