7-13
Cisco SCE 8000 10GBE Software Configuration Guide
OL-30621-02
Chapter 7 Configuring Line Interfaces
Tunneling Protocols
Configuring IPinIP Tunneling
•
Enabling IPinIP Tunneling, page 7-13
•
Disabling IPinIP Tunneling, page 7-13
IPinIP is an IP-based tunneling protocol; therefore the system must be specifically configured to
recognize the flows inside the tunnel. The Cisco SCE platform will then skip the external IP header,
reaching the internal IP, which is the actual subscriber traffic. When IPinIP skip is disabled, the system
treats the external IP header as the subscriber traffic, resulting in all IPinIP traffic being reported as
generic IP.
Guidelines for configuring IPinIP tunnels:
•
IPinIP and other tunnels: IPinIP is supported simultaneously with plain IP traffic and any other
tunneling protocol supported by the Cisco SCE platform.
•
Overlapping IP addresses: There is no support for overlapping IP addresses within different IPinIP
tunnels.
•
DSCP marking: For IPinIP traffic, DSCP marking can be done on either the external or the internal
IP header exclusively (see
“Configuring DSCP Marking” section on page 7-14
).
Caution
IPinIP tunneling can be configured (enabled, disabled or DSCP marking configuration) only when there
is no application loaded or the linecard is shut down.
Fragmentation
Fragmentation should be avoided whenever possible. If it is not possible to avoid fragmentation, it is
recommended to opt for internal fragmentation. If that is also not possible, the Cisco SCE platform can
be operated under conditions of external fragmentation
Enabling IPinIP Tunneling
By default, IP tunnel recognition is disabled. Use this command to configure recognition of IPinIP
tunnels and skipping into the internal IP packet.
Step 1
Shut down the linecard. (This is a root level command.)
From the SCE(config if)#> prompt, enter
shutdown
and press
Enter
.
Step 2
Enable IPinIP tunneling.
From the SCE(config if)#> prompt, enter
ip-tunnel IPinIP skip
and press
Enter
.
Step 3
Restart the linecard.
From the SCE(config if)#> prompt, enter
no
shutdown
and press
Enter
.
Disabling IPinIP Tunneling
Step 1
Shut down the linecard. (This is a root level command.)
From the SCE(config if)#> prompt, enter
shutdown
and press
Enter
.
Step 2
Disable IPinIP tunneling.
From the SCE(config if)#> prompt, enter
no
ip-tunnel IPinIP skip
and press
Enter
.