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‘学习笔记’ 分类存档

Direct boot eXR ISO by iPXE

The article should applies to all eXR platform, include ASR9k, Cisco8000, NCS5500, NCS6k. The output information maybe different by diff platform, but the iPXE method should same. Btw in eXR, if you want to recovery password, will require iPXE.

Enable HTTP Service at linux

[root@nso exr]# python -m SimpleHTTPServer
Serving HTTP on 0.0.0.0 port 8000 ...

完整阅读

ISIS Flexalgo affinity exclude some link from the Slice

  • Choose 2-3 router for FAD, but not all router
  • Config follows configuration at FAD router:
router isis srte
affinity-map red bit-position 23
flex-algo 128
 priority 200
 metric-type delay
 advertise-definition
 affinity exclude-any red
  • Config follows configuration at exclude/include function router:
router isis srte
affinity-map red bit-position 23
flex-algo 128
 metric-type delay <-- define in FAD
 affinity exclude-any red
!
inter gix/x/x/x
 affinity flex-algo red
  • Config follows configuration at normal router:
router isis srte
flex-algo 128
  metric-type delay <-- define in FAD

Segment Routing Microloop Avoidance – 微环避免

对于SR的微环避免,很多人不是特别清楚细节,所以我将在此简单总结下,希望对阅读此篇文章的人有所帮助,我会围绕以下几个话题展开讨论:

  • 微环路是什么?微环避免能做什么?
  • 微环避免跟TI-LFA有什么关系?
  • 微环避免和TI-LFA同时存在的情况下,是否都会有作用?

为了方便大家理解,我将用一个topology来讨论我们今天涉及的所有内容,关于这部分更详细的内容,可以参阅SR卷一的9.10章节,以及SR卷二的8.11.1章节;另外此分析只作为问题验证说明,不能直接拿到现网使用,如40s的delay等,这些需要根据IGP的Scales以及硬件的收敛性能来做调整

完整阅读

Telemetry Solution Demo with IOS XR

I put a telemetry demo to youtube at last year, but no more time summary… now I summaried in the article, will help you to easy build up the solution. Due to original testbed had changed, so follow some info maybe change, but all procedure should same. And XR configuration file is original. Demo video at this link:

Install Grafana and Influxdb by Docker

docker run -d -v grafana-storage:/var/lib/grafana -p 3000:3000 grafana/grafana:5.4.3
docker run -d --volume=/opt/influxdb:/data -p 8080:8083 -p 8086:8086 tutum/influxdb

Install Pipeline

git clone https://github.com/cisco/bigmuddy-network-telemetry-pipeline.git

Config Pipeline

完整阅读

TigerVNC on ubuntu 20.0

Install Desktop Gnome

root@server-test:/opt# apt-get install -y ubuntu-desktop

Install/Config TigerVNC

root@server-test:/opt# apt -y install tigervnc-standalone-server
......
root@server-test:/opt# vncpasswd
Password:
Verify:
Would you like to enter a view-only password (y/n)? n
root@server-test:~# more /root/.vnc/xstartup
# create new (or add to the end)
exec /usr/bin/gnome-session &
# start with diplay number [1], screen resolution [800x600]
root@server-test:~# 
root@server-test:~# vncserver :1 -geometry 800x600 -localhost no

New 'gcsprendpoint-yonzhao2test-share-flat2-ni9ngm-server-ne.novalocal:1 (root)' desktop at :1 on machine gcsprendpoint-yonzhao2test-share-flat2-ni9ngm-server-ne.novalocal

Starting applications specified in /root/.vnc/xstartup
Log file is /root/.vnc/gcsprendpoint-yonzhao2test-share-flat2-ni9ngm-server-ne.novalocal:1.log

Use xtigervncviewer -SecurityTypes VncAuth,TLSVnc -passwd /root/.vnc/passwd gcsprendpoint-yonzhao2test-share-flat2-ni9ngm-server-ne.novalocal:1 to connect to the VNC server.

Access by TigerVNC Client

Other

2020-07-24 Update: Change to TightVNC

I found an issue that cannot input anything when login via tigerVNC, normal user is ok after disable screen auto clock, but root couldn’t login in. So I transfer to TightVNC that work perfect now. Follow install guide:

How to Install and Configure VNC on Ubuntu 20.04
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