Anilkumar Dantu CCIE (22536) IOS XR Introduction Anilkumar Dantu CCIE (22536) HTTS, Cisco Systems

IOS XR Introduction - Agenda Carrier Grade NOS Features Expectation and OS Concepts Welcome to XR OS XR OS packaging XR OS installation Configuration in XR OS Troubleshooting in XR

Carrier Grade NOS Feature Expectations Scalability High Availability Security Flexibility It is not that IOS does not meet these expectations. Only extent to which it can meet these expectations in future was getting challenged due to its OS structure.

OS terminologies Operating system, Kernel , CPU , memory , I/O , Applications , processes etc OS OS Monolithic Kernel Micro kernel

Distributed subsystems/processes Memory-protected microkernel Welcome to XR OS Core OS Capabilities(QNX Based Micro Kernel) - Protected process memory space - Preemptive Scheduling - Plane separation & fault isolation Distributed subsystems/processes Microkernel Scheduling IPC mech. Memory mgmt. H/W abstraction BGP RIP IS-IS OSPF Routing Policy PIM IGMP RIB L2 Drivers ACL FIB QoS LPTS Host Services PFI Interfaces Data plane CLI SNMP XML Netflow Alarm Perf. Mgmt. SSH Management plane Control plane Control Plane Routing policy L2 drivers Host services Perf. mgmt. System services Memory-protected microkernel

Welcome to XR OS contd… More than 200+ Processes. Checkpoint support for process Restart and process level Redundancy

IOS Vs XR OS IOS XR Kernel Monolithic Micro kernel Memory Shared Protected Scheduling of process Priority based- Non-preemptive Priority based- preemptive Process stop/restart No Yes Modular architecture Services running mode Kernel mode Application/user space mode

XR OS packaging Inline with its software architecture XR OS Software is available as a modular package. On CCO we can download XR OS in form of Tar file eg : - XR12000-iosxr-4.1.0.tar Once file is untarred – we see Cisco IOS XR Bootable Files, PIEs, and SMUs

XR OS packaging contd… Cisco IOS XR Bootable Files, PIEs, and SMUs Files ending with .vm extension are bootable files. VM file contains – operating system kernel , Base image , admin plane functions , routing & forwarding bundles. VM files is used to boot router during fresh installation or as last resort recovery. Installation of the .vm image file results in the installation of a number of individual packages. PIE (Package installation envelope) : Upgrade packages, Optional additional packages SMU (software Maintainence units) : These are fixes Or patches for Bugs. Eg- c12-4.1.0.CSCto40258.pie MPLS MCAST MGBL SEC Mandatory Optional OS-MBI Base Admin Forwarding Line card Routing

XR OS Installation In XR TURBO-BOOT refers to booting of Router from ROMON mode. TURBO-BOOT is required during IOS to XR conversion or recovery of router from ROMON mode. TURBO_BOOT steps: - First step is to verify existing ROMON settings by querying it using “set” command -you can use “unset Variable” command to clear existing settings -Second step is to set the TURBOBOOT variable in ROMON to a non-volatile storage where .vm file is stored. - Last step is rommonB7> boot disk0:c12k-mini.vm-4.1.0

XR OS Installation contd… - With TURBOBOOT variable in ROMON set to “on” and boot command starts the TURBOBOOT process. Here XR OS is loaded into memory & after verification of disk space ,OS is copied to the disk. Once OS is copied to disk , boot variable is set to disk0: product_osmbi_4.1.0/product-rp.vm & config register is set to 0x102. After that node is reloaded to boot from disk0: the new boot variable. This completes the TURBOBOOT process. Once installation of XR OS is complete and we can verify the details using commands show install active summary show version Installation/booting with .vm file give only basic routing & forwarding capability. For additional capability you need to install specific PIE files. Install add disk0:package_name.pie activate

XR Hardware Requirements From XR OS installation procedure we have seen flash disk (disk0: , disk1:) is used extensively for loading XR image , config files (running configs , roll back configs) , PIEs , SMUs etc. So pulling out flash disk from running node will make node unresponsive/reload. Make sure RP cards has appropriate disk space available , RP & LC hardware are compatible with XR as OS, and also verify the RP, LC has minimum firmware (romon, fpd) level to boot up in XR. Many of the XR supporting nodes RP cards will have a harddisk (40GB or more) used basically for archiving of logs, dump files , additional sw packages.

XR Configuration & files - In XR there is no differentiation as startup-config & running config as in IOS. - In XR configuration is divided into Admin plane , share plane & local plane. Hence the configuration file structure is also developed to support it. Here running configuration is stored in binary format (known as primary persistent configuration) as compared to ASCII format of startup/running config in IOS. Configuration file stored in binary format helps in faster loading during bootup. And added features of commit reference points, rollback is made possible.

XR Configuration (Two stage commit)

Troubleshooting in XR RP & LC states. Logs & storing of wrapped logs, Show tech files Traces captures Process crash traceback decodes