Cisco Cisco Packet Data Interworking Function (PDIF)
Reverse Route Injection
▀ High Availability for RRI
▄ SecGW Administration Guide, StarOS Release 18
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High Availability for RRI
Interchassis Session Recovery (ICSR) is implemented for RRI to ensure that the routes are injected correctly on the
appropriate VSM to route the traffic to the correct interface after an ICSR switchover.
appropriate VSM to route the traffic to the correct interface after an ICSR switchover.
ICSR can be implemented for:
Intrachassis or cluster card-level redundancy
Interchassis L2 card-level redundancy
Interchassis L3 card-level redundancy
Important:
RRI is mandatory for S2S StarOS WSG service and optional for RAS.
Intrachassis/Cluster Redundancy
This mode only supports Layer 2, 1:1 redundancy between VPC-VSM instances (StarOS VMs) across two VSMs in the
same ASR 9000 chassis. Both instances are located in the same chassis and, therefore, the routes injected by the active
VPC-VSM instance to the IOS-XR will still be valid after the failure when the standby card takes over. In this case, the
NPU Manager on the standby VSM does not inject the routes to the IOS-XR. The routes only need to be added to the
Route DB.
same ASR 9000 chassis. Both instances are located in the same chassis and, therefore, the routes injected by the active
VPC-VSM instance to the IOS-XR will still be valid after the failure when the standby card takes over. In this case, the
NPU Manager on the standby VSM does not inject the routes to the IOS-XR. The routes only need to be added to the
Route DB.
The main requirements for ICSR in this mode are:
The route DB on the standby VSM must contain only routes that have been successfully injected by the active
VPC-VSM instance.
To prevent IOS-XR from removing the routes, CALP on the standby StarOS VM reconnects to the CA server via
the same session ID used prior to the timeout. The session ID is stored in the shared configuration task (SCT)
of the CA Controller and a new micro-checkpoint is sent to the standby VPC-VSM instance.
of the CA Controller and a new micro-checkpoint is sent to the standby VPC-VSM instance.
The session manager which programs the IPSec manager and other sessions managers synchronizes the tunnels with the
standby VPC-VSM instance via SRP.
standby VPC-VSM instance via SRP.
Interchassis Redundancy
Overview
This mode supports hot standby redundancy between two VPC-VSM instances in different ASR 9000 chassis. The
standby instance is ready to become active once a switchover is triggered. SA re-negotiation is not required and traffic
loss is minimal.
standby instance is ready to become active once a switchover is triggered. SA re-negotiation is not required and traffic
loss is minimal.
The Interchassis Session Recovery (ICSR) model supports both Layer 2 and Layer 3 levels of redundancy. Basic ICSR
requirements are:
requirements are:
The route database on the standby VSM must contain only the routes that were successfully injected by the
active VSM.