Gre Tunnel Interface Rule - Cisco ASR 5000 Series Administration Manual

▀ Interface and Port Engineering Rules
The logical interface(s) that will be used to facilitate the Pi interface(s) must be configured within an ingress
context.
HA services must be configured within an ingress context.
If the system configured as an HA is communicating with a system configured as a FA, then it is recommended
that the name of the context in which the HA service is configured is identical to the name of the context that
the FA service is configured in on the other system.
Each HA service may be configured with the Security Parameter Index (SPI) of the FA that it will be
communicating with over the Pi interface.
Multiple SPIs can be configured within the HA service to allow communications with multiple FAs over the Pi
interface. It is best to define SPIs using a netmask to specify a range of addresses rather than entering separate
SPIs. This assumes that the network is physically designed to allow this communication.
Each HA service must be configured with a Security Parameter Index (SPI) that it will share with mobile nodes.
Depending on the services offered to the subscriber, the number of sessions facilitated by the Pi interface can be
limited in order to allow higher bandwidth per subscriber.

GRE Tunnel Interface Rule

The following engineering rules apply to the GRE tunnel interface between two GRE tunnel nodes:
A maximum of 512 IP tunnels (511 GRE tunnels + 1 not tunnel interfaces) are allowed to configure in a context
but subject to a maximum of 2048 GRE tunnels per chassis.
▄ Cisco ASR 5000 Series Gateway GPRS Support Node Administration Guide
Engineering Rules
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