Everyone today talks about the programming language Python while discussing Software-defined Networking (SDN). Since Python is so popular, it would be a good idea for network administrators to know more about Python. First thing first. I talk about how I prepare Python running environment on Microsoft Windows.
It would be nothing special if I only download the installation software from Python official web site by mouse clicking. Instead, I use PowerShell to download and install for me. That is, prepare one scripting running environment using another scripting language.
The routing protocol Intermediate System to Intermediate System (IS-IS) is an advanced and robust link-state protocol used in many service provider networks. Most of the other enterprises I know of prefer to use protocols like OSPF or EIGRP instead of IS-IS. Therefore, enterprise administrators might not be familiar to this protocol at all.
Here I want to share my short note to start IS-IS quickly without digging into protocol details. In case you must configure and maintain an IS-IS network, this note might save you some time.
On April 22, 2017, one segment of Asia-Pacific Cable Network 2 (APCN2) that serves Taiwan’s major Internet connectivity with Japan, Europe, and America, was broken. According to some news sources, it might take one month just to fix this outage. I live in Taiwan, and I do feel the Internet speed became slow after this outage. I was wondering how could the repairing take one month.
I want to know how to repair a broken submarine fiber cable. I searched on Google and I found this video. This video was created and published by TE SubCom. I summarize the key steps mentioned in this video, and I also added some of my own notes all in this post. I hope this post together with the original video would help you to understand the repairing operation as well.
A friend asked a good question about how this command works on Cisco MDS FibreChannel switch: “switchport trunk allowed vsan all”.
To my surprise, I cannot find any specific official documents to explain it clearly. I did some experiment on one Cisco MDS 9148. And here is my conclusion.
Bay, beach, and cliff near Chung-De Station. (崇德海灣).
Hualian County, Taiwan.
This is just a short notice for you in case you are not aware of it. Cisco announced a vulnerability on Cisco IOS and IOS XE operating system. For short, you only have to disable incoming TELNET service onto the router itself to avoid this vulnerability. You can use Secure Shell (SSH) instead for remote management. SSH is not vulnerable in this problem.
The Jin-Dai Bridge (錦帶橋) in Dahu Park (大湖公園). Taipei City, Taiwan.
