Ask the Expert: IOS-XR Architecture and Troubleshooting

[Monica Lluis]

This session will provide an opportunity to learn and ask questions about Cisco IOS XR Software architecture which is modular and fully distributed network operating system used by most of the leading service providers in the industry. IOS XR is widely used in big platforms like GSR, CRS, NCS and ASR9K etc. You will also learn different troubleshooting scenarios and use cases on Cisco IOS XR Infrastructure, Configuration Management, XR Monitoring and Operations, process crash decode etc. c.

To participate in this event, please use the Reply Button to ask your question.

Ask questions from Monday June 6 to Friday June 17, 2016

Featured Experts

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, ASR 9K and Cisco XR 12000 Series Routers. Raj has more than 10 years of experience in the IT industry and holds double CCIE certification (38760) in routing and switching and Data Center. He has already delivered webcast and other ask the expert session on cisco support community.

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 GSR, CRS, ASR 9K and Cisco XR 12000 Series Routers. Sudhir has more than 12 years of experience in the IT industry and holds CCIE certification (35219) in Service provider and Routing and switching and Data Centers. He has already delivered webcast and other ask the expert session on cisco support community. 

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[Sudhir Kumar]

Hi Suhail,

I just tested and confirmed that RSA key gets stored at below location.

It may vary depends on which product , but below one is for GSR, CRS and ASR9k platform.

Directory of nvram:

nvram:cepki_key_db

Example:

RP/0/7/CPU0:PE1#dir nvram:

Directory of nvram:

7           -rw-  1878        <no date>              cepki_key_db

Thanks
Sudhir Kumar

[solaikumar k]

Hi ,

Good Day !!

Can you share some reference document to understand the architecture of IOS-XR.

[Sudhir Kumar]

Hello Solai,

please find the below references for IOS-XR architecture study.

https://supportforums.cisco.com/document/12361461/ios-xr-fundamentals-and-architecture-faq-live-webcast

https://www.ciscolive.com/online/connect/sessionDetail.ww?SESSION_ID=5339

http://www.ciscopress.com/store/cisco-ios-xr-fundamentals-9781587052712

Thanks
Sudhir Kumar

[Wilson Gabriel Veliz Plua]

Good Day

Can you share any link (webcast) where we can study and learn more about  XR architecture.

Regards

Wilson Veliz Plua

[Sudhir Kumar]

Hi Wilson,

Please find the below references for IOS-XR architecture study.

https://supportforums.cisco.com/document/12361461/ios-xr-fundamentals-and-architecture-faq-live-webcast

https://www.ciscolive.com/online/connect/sessionDetail.ww?SESSION_ID=5339

http://www.ciscopress.com/store/cisco-ios-xr-fundamentals-9781587052712

Thanks
Sudhir Kumar

[Wilson Gabriel Veliz Plua]

Thanks

Another question: How many links and which ports I have to select to form a cluster and use the capability of nv? Is there any reference for this design ?

Regards

Wilson Veliz P.

[Sudhir Kumar]

Hi Wilson,

nV clustering control Ethernet links refers to the front panel SFP+ ports.

nV IRL ( LC port ) connection refers to forwarding traffic between chassis.

As per below documentation maximum of 16 such links between the chassis and recommended is a minimum of 2 links

Please find below links for nV clustering details

ASR9000/XR: Cluster nV-Edge guide

https://supportforums.cisco.com/document/127061/asr9000xr-cluster-nv-edge-guide

ASR9000/XR NV Edge Deployment Guide
https://supportforums.cisco.com/document/145436/asr9k-nv-edge-deployment-guide

Please rate helpful posts and mark correct answers.

Thanks
Sudhir Kumar

[Aleksandar Vidakovic]

hi Wilson,

in addition to what Sudhir wrote, please note that the Tomahawk generation of line cards don't support nV Edge (aka cluster). With the introduction of BNG Geo Redundancy, we can now offer a solution for chassis redundancy in all asr9k deployment scenarios. If you are not considering cluster because of BNG, we recommend MC-LAG or Pseudo MC-LAG solution instead of cluster.

regards,

Aleksandar

[Florian Frotzler]

Hi,

I find it very annoying that when you install a new service pack, the old one is still active. You can deactivate and remove it, but I would expect that it goes superceeded automatically. When will this be fixed?

Florian

[Sudhir Kumar]

Hi Florian,
Greetings

Thanks for contacting us on this forum. To understand your question in detail ,Could you please specify the new service pack and old one ? I will check on this and get back to you.

Thanks
Sudhir Kumar

[Florian Frotzler]

I see this with 5.1.3, the SP number does not really matter, I have seen it recently with SP7 -> SP9 upgrade.

Florian

[Anilkumar Dantu]

In Cisco IOS XR software Release 4.3.0 and later, use the show install superceded admin command in order to help identify SMUs that have been fully superceded by other active SMUs.

“admin show install superceded”

“admin install deactivate superceded”

“install commit”(optional) to hold your current active software and “install remove inactive”.

Need to double check if it is in roadmap to automate this step in future releases. Will confirm back.

Thanks and regards

Anilkumar Dantu

[Florian Frotzler]

Hi,

As I stated before, the old SP is NOT being marked as superceeded.

Florian

[Sudhir Kumar]

Hello Florian,
Greetings

This looks to be cosmetic bug tracked under: CSCuw19292 : Inactive Feature or Service pack shows up in show install active summary

Please review this DDTS, looks like supercede calculation is not performed on them.

https://tools.cisco.com/bugsearch/bug/CSCuw19292/

Fix will be included in XR 6.1.1 and it’s going to be also included in 5.3.4.

Thanks
Sudhir Kumar

[Wilson Gabriel Veliz Plua]

Good Day Sudhir,

I'm new and I want to know which is the meaning of "cosmetic bug" or when people use that term.

Regards

Wilson Veliz.