Ask the Experts: IOS-XR Fundamentals and Architecture

[ciscomoderator]

Welcome to the Cisco Support Community Ask the Expert conversation. 

Learn and ask questions about IOS-XR Fundamentals and Architecture.

November 18, 2014 through November 28, 2014.

Cisco IOS XR Software is a modular and fully distributed network operating system for service provider networks. Cisco IOS XR creates a highly available, highly secure routing platform.

It distributes processes across the control, data, and management planes with their own access controls and delivers routing-system scalability, service isolation, and manageability.

This is a Q&A extension of the Live expert Webcast.

Cisco subject matter experts Sudeep, Raj, and Sudhir, will focus on IOS-XR fundamentals.

Including:-

• High-Level Overview of Cisco IOS XR
• Cisco IOS XR Infrastructure
• Configuration Management
• Cisco IOS XR Monitoring and Operations
• Cisco IOS XR Security
• Introduction to different IOS-XR platforms

Sudeep Valengattil is a customer support engineer in High-Touch Technical Services at Cisco specializing in service provider technologies and platforms. Sudeep has got experience on XR platform like ASR9000, CRS, NCS and GSR. Sudeep has more than 9 years of experience in the IT industry and holds CCIE certification (36098) in Service provider.

Sudhir Kumar is a customer support engineer in High-Touch Technical Services at Cisco specializing in service provider technologies and platforms. His areas of expertise include Cisco CRS, ASR 9K and Cisco XR 12000 Series Routers. Sudhir has more than 10 years of experience in the IT industry and holds CCIE certification (35219) in Service provider and Routing and switching.

Raj Pathak is a customer support engineer in High-Touch Technical Services at Cisco specializing in service provider technologies and platforms. He serves as a support engineer for technical issues supporting Cisco IOS XR Software customers on Cisco CRS and Cisco XR 12000 Series Routers. Raj has more than 8 years of experience in the IT industry and holds CCIE certification (38760) in routing and switching.

For more information about this topic, visit the Expert Corner > Knowledge Sharing

Remember to use the rating system to let the experts know if you have received an adequate response.

 

[Gustavo Hernandez]

Hello,

I have a RSP2 ASR 9010. Should I download the PX packet in order to upgrade to version 4.3.1?

[Sudeep Valengattil]

Hi Whitlelisa,

Greetings!

To answer you, we have a combo image release from 4.3.0 onwards, to support both x86 (-px) and ppc (-p) based hardware. The combo image will still be called asr9k-mini-px.vm.

Here is a link which has all upgrade instructions.  You can keep this handy.

http://www.cisco.com/web/Cisco_IOS_XR_Software/index.html

Regards,  Sudeep Valengattil

[Aman Soi]

Hi Sudeep/Raj/Sudhir,

I attended the session which was Gr8 but I could only hear audio.

Can u share the link from where I can download Presentation/Video?

regds,

aman

[Raj Pathak · Accepted solution]

Hello Aman,

Here is the link for web-ex recording.

https://supportforums.cisco.com/video/12356066/live-webcast-ios-xr-fundamentals-and-architecture

[Charles Patrick]

Have gone through the recording. Topics covered very well. Thanks Guys.

[steve carell]

Hello Guys,

I went through the recording session and I found topics covered very well !!

Can you please help me to understand where does XR save the config after commit ?

Steve

[Sudeep Valengattil]

Hi Steve,

All the configs would be arranged in a series of directories under folder disk0:/config.  We have the primary persistent configs stored under folder “disk0:/config/lr/running” for the shared plane and admin plane config would be under “disk0:/config/admin”.  These files will be saved in binary format.

We also have a backup config (similar to startup config in IOS) under directory disk0:/config/running.  The file name would be alternate_cfg which is in ASCII format.  This will serve a fall back option, if there is any corruption in primary persistent config and the system is not able to use it.

Here is an example o/p for the Tengig interface config which we have in router.

RP/0/RP0/CPU0:CRS-C#dir disk0:/config/lr/running/absref1 | in Ten
Wed Nov 19 09:51:53.727 EDT
889981568   -rwx  1860        Mon Nov 17 15:15:35 2014  TenGigE0_0_0.bin
889981664   -rwx  245         Mon Nov 17 15:15:35 2014  TenGigE0_1_0.bin
889981760   -rwx  117         Mon Nov 17 15:15:36 2014  TenGigE0_2_0.bin
889981856   -rwx  197         Mon Nov 17 15:15:36 2014  TenGigE0_2_1.bin
889981952   -rwx  306         Mon Nov 17 15:15:37 2014  TenGigE0_2_2.bin
889982048   -rwx  331         Mon Nov 17 15:15:37 2014  TenGigE0_2_3.bin
889982144   -rwx  333         Mon Nov 17 15:15:38 2014  TenGigE0_2_4.bin

Regards,

Sudeep Valengattil

[Wilson Gabriel Veliz Plua]

Hello Everybody

Can you help me.

What command can I use to see the history proccess cpu ?. i.e. in IOS  I can see with this command show proccess cpu history.

Thanks

[Sudeep Valengattil]

Hey Wilson,

Thanks for your question

This feature, "show proc cpu history" that you used to have in IOS is not available in
any of the platforms running IOS-XR at the moment.  In general, higher CPU utilization on IOS XR is less of a concern than on classic IOS.  IOS-XR has a preemptive multitasking kernel that ensures all processes/threads receive fair CPU cycles.

To have a view of live utilization, you can use this command “monitor process”.  It by default will sort based on CPU, but if you want to sort by memory, press “M” on your keyboard.

387 processes; 2279 threads; 2263 timers, 12094 channels, 17964 fds
CPU states: 93.2% idle, 5.4% user, 1.3% kernel
Memory: 4096M total, 1904M avail, page size 4K

      JID TIDS Chans  FDs Tmrs   MEM   HH:MM:SS   CPU  NAME
      214    3   16   33    5     3M    2:42:34  3.64% fab_xbar
        1   13  390  283    1      0  486:02:00  1.34% procnto-booke-smp-instr
    65785    1    1    7    0     1M    0:00:00  0.86% ptop
       89   10  288    7    2     2M    1:52:37  0.33% qnet
       60   19   49   24    8    16M    2:02:00  0.19% eth_server
      244   21  196  188    4     8M    0:17:22  0.09% gsp

If you wish to track CPU utilization on IOS-XR over time, it is recommended you track this
through an SNMP application by polling mibs.

For more details on monitoring CPU and Memory in XR, please refer below link

https://supportforums.cisco.com/document/9881576/asr9000xr-monitoring-cpu-and-memory

Do let me know if you have any queries.

Regards,

Sudeep Valengattil

[steve carell]

Hello Experts,

Could you please let me know what is main difference between P and px images in IOS-XR ?

Steve

[Sudhir Kumar]

Hi Steve,

Thanks for you question.

P images can only support Power PC hardware, while px images can support both Power PC and Intel hardware.

PowerPC is a microprocessor, It is built with reduced instruction-set computer (RISC) which speeds-up the operation of MIPS (million instructions per second). PowerPC is mainly based on IBM’s earlier Power architecture because it has a similar RISC instruction set for microprocessors.

Intel CPU's are based on CISC architectures. Typically CISC chips have a large amount of different and complex instructions. The philosophy behind it is that hardware is always faster than software, therefore one should make a powerful instruction set, which provides programmers with assembly instructions to do a lot with short programs. In common CISC chips are relatively slow (compared to RISC chips) per instruction, but use little (less than RISC) instruction.

Please let me know if you need any other clarification.

Thanks,
Sudhir Kumar
Cisco Systems

[steve carell]

Thank you Sudhir for your quick response. I got the answer , well explained.

Steve

[Charles Patrick · Accepted solution]

hi,

I was going through your recording , need to understand where is the LPTS policer applied ?

Thx
Charles

[Sudhir Kumar]

Hi Charles,

LPTS Policer applied in Ingress line card. In IOS XR, the control packets, which are destined to the Route Processor are policed using a set of ingress policers in the incoming line cards. You can change the policer values based on the flow types of these set of ingress policers.

I hope this answers your question.

Also, you can refer cisco document using below link

http://www.cisco.com/c/en/us/td/docs/routers/xr12000/software/xr12k_r4-2/addr_serv/configuration/guide/b_ipaddr_cg42xr12k/b_ipaddr_cg42xr12k_chapter_0111.html

Thanks
Sudhir Kumar
Cisco Systems