The slides for "エンジニアが語る！Cisco Live US 2019 in San Diego まとめ"

1. Findings in CLUS 2019
エンジニアが語る！Cisco Live US 2019 in San Diego まとめ
Nakajima@LINE

2. About Me
Ikuo Nakajima (ikuo.nakajima@linecorp.com)
network engineer at service network team in IT Service Center
Responsibility
Network Design and Deployment for Data Center

3. About Our Network
JANOG43: https://www.janog.gr.jp/meeting/janog43/program/line
ENOG55: http://enog.jp/archives/2014

4. Goal of this presentation
To share the advantages in CLUS to encourage you to join the CLUS 2020

5. The advantages in CLUS (from my experience)
Closing the distance to new features
Closing the distance to engineers in U.S.

6. Featured sessions in this talk
Packet Capture
Overview of Packet Capturing Tools in Cisco Switches and Routers -
BRKARC-2011
Telemetry
NX-OS Automation and Telemetry Made Simple, Powerful and Scalable
with Open-Source Tools - BRKDCN-2025

7. Packet Capture
Motivation
We want to know commands to check how service traffic is forwarded on
Nexus switches.
Use-case
To check if the switch forwards the traffic to trouble shoot network
problems.

8. Question: Do you know the feature called "ELAM"?
(If not, the following slides can be worth reading.)

9. The chart in the session showing Packet Capturing Tools
The red boxes indicate tools for NX-OS

10. Once I tried ELAM and FNF that seems available on Nexus switches,
But couldn't find out if they are available on the specific HW and OS version I'm using.
So I put the question on the webex teams just for the attendees.

11. One of speakers gave me the reply sooner than I expected!!
He said ELAM should be available on my device.
It helped me a lot to try the feature in my environment very soon.

12. (From here, introductions of the packet capturing tools follow)
ELAM (Embedded Logic Analyser Module) is
the tool to check the input and output ports on the device just for the specific flow.

13. CLI commands shown here are to capture and display the result. (condition: N9K, NX-
OS
7.x)
Commands in the red box specify the HW to capture the traffic.
Ones in the blue box define the flow to be captured.

14. The output below shows Src Index and Dest Index for input and output ports.
No result means the flow doesn't come to the device.

15. In the session, they explained the packet drop caused by ACL.
This can be identified with the undefined dest_index.

16. As a much easier way, you can use Packet Tracer.
(It's only available on the switch with Trident II though...)

17. ACL option "per-entry" can be another way to display
the statistics for flow entries.

18. Caution: please be aware of the TCAM Resouce Usage
By default
N7K would try
to merge features when programming the TCAM, which helps saving the TCAM
resource. When statistics per entryis configured, the entries are not merged to
maintain per-Access Control Entries (ACE) stats, in which case
it could take more resources.

19. What I found in the session about Packet Capture Tools for Nexus Switches was
The widely available tools are ELAM and per-entry.
The advantage to attend CLUS so far was
the swift and good reply from speakers in the private teams space for attendees.
(This is totally up to speakers)

20. Featured sessions in this talk
Packet Capture
Overview of Packet Capturing Tools in Cisco Switches and Routers -
BRKARC-2011
Telemetry
NX-OS Automation and Telemetry Made Simple, Powerful and Scalable
with Open-Source Tools - BRKDCN-2025

21. Quoted from the last slide at JANOG
43

22. To achieve the sustainable and scalable network,
many users and architects take open-source tools into considerations.

24. We'd like to have bidirectional conversations to share use-cases and results,
not unidirectional ones like requests to develop new features.

25. In CLUS, we could have a chance to share our use-case, tools and issues.
During the meeting, the other meeting was set to meet the person for the deeper
discussion.
Then we could meet on the next day in the morning.
It was possible just because we were in U.S.

26. Cisco Live US makes it possible to meet engineers in U.S. in person.

27. Then when I'm back home, I tried telemetry

28. Telemetry
Motivation
I wanted an easy way to log test results.
Use-case
To check the impact from the route injection
To check the detoured traffic with ospf peer changes

29. In the route injection scenario, we could observe
multiple statitic changes in the same time range with
timelion in Kibana.

30. Ansible shows the timestamp and the diff in config
which help us to trace the results in Kibana.

31. The advantages in CLUS
Closing the distance to new features
Not just to know the feature but to be able to use the feature.
Closing the distance to engineers in U.S.
Meet engineers in U.S. in person and start bidirectional communication.

32. Action items for the next CLUS to make the best of it
Register the session in advance.
Make the document for your use-case and test conditions to share before the
meeting
Join events in DevNet
Attend with your colleague
Enjoy!

33. Let's join Cisco Live US 2020!