Question

A service provider runs Cisco IOS XR on its core routers. During a maintenance window, an engineer must patch the BGP process to fix a defect. Management insists that the router must NOT reload and that OSPF, LDP, and interface forwarding must remain unaffected while BGP is updated. Which characteristic of the IOS XR software architecture makes this possible?

Accepted Answer

IOS XR uses a modular microkernel design where each process runs in a protected memory space, allowing an individual process to be restarted or patched independently

Answer

IOS XR runs all routing protocols as a single monolithic image, so patching requires an in-service software upgrade of the entire control plane

Answer

IOS XR relies on a shared memory pool for all processes so that restarting one process automatically refreshes all others

Answer

IOS XR requires that the standby route processor take over before any protocol process can be modified, forcing an RP switchover