Configuring Secure Domain Routers on Cisco IOS XR Software
Information About Configuring Secure Domain Routers
•To access install commands, you must be a member of the
•Most show install commands can be used in the EXEC mode of an SDR to view the details of the active packages for that SDR.
Note For information, see Default Configuration for New
DSC Migration on Cisco CRS-1 Multishelf Systems
Designated Shelf Controller (DSC) migration is the act of moving the DSC role to a different part of the router. The DSC role automatically migrates when the DSC cannot perform its function on the shelf in which it currently resides. The cause of a DSC migration can be a failure of both of the RPs in the DSC shelf or any event that removes power from the DSC line card chassis (LCC).
DSC migration can be triggered by the following methods:
1.Shutdown power to DSC LCC. (Recommended)
2.
3.Online, insertion, removal (OIR) for an active RP and standby RP in a DSC LCC simultaneously. (Not recommended)
4.Removal of control Ethernet connectivity to both RPs in a DSC LCC. (Not recommended)
Note If planned downtime of a DSC LCC occurs, the recommended method of triggering DSC migration is to shutdown the power to the DSC LCC. The methods, which are not recommended, shutdown only one transport medium in the system. For example, control Ethernet but fabric medium can still be up for another 30 seconds. This causes an inconsistent system view in the named SDR using DRP paired across the rack in which the DRP loses control Ethernet connectivity, but the LR plane is still working and can bring the named SDR into an inconsistent view if the named SDR is across the rack.
To support DSC migration in Cisco IOS XR Software Release 3.3.2 and higher, we recommend that you:
•Keep the default placement of all four RPs in the owner SDR. When the owner SDR spans both LCCs, the impact on the SDR resources is minimal in the remaining rack. Existing connections are not interrupted for the resources in the remaining rack, but a delay in routing new connections can occur while the routing tables are updated.
•Run all routing protocols in a named SDR. In addition, by running all routing protocols in a named SDR, which requires a distributed route processor (DRP) paired across the rack, the operation of Cisco Nonstop Forwarding (NSF) and Cisco Nonstop Routing (NSR) continues.
An election process selects the node that is to receive the DSC role upon DSC migration. The basis of the election is the shelf number. The shelf with the lowest number is designated to receive the DSC role.
DSC migration can cause a very short interruption to traffic flowing through the owner SDR. Although the time can vary with the addition of new features to DSC management and other factors, in the current release the time is likely to be around 20 to 30 seconds.
The reason for the traffic loss is because virtual Interfaces (VI), such as loopback, null, tunnels, and bundles are hosted on the DSDRSC of an SDR. For the owner SDR, the DSDRSC is the same node as the DSC itself. For DSC migration to occur, both active and standby DSC must be lost. Therefore, for the owner SDR, both active and standby DSDRSC are lost. VI's must be recreated on the new DSC,
Cisco IOS XR System Management Configuration Guide
