iTerm2 Tip: Repeating Commands Using a Coprocess
iTerm2 is a great terminal for MacOS; far better than Apple’s built-in Terminal app, and it’s my #1 recommendation for Mac-based network engineers. One of the many reasons I like it is that it has a feature that solves a really annoying problem.
It’s tedious having to issue a command repeatedly so that you can see when and if the output changes. I’ve had to do this in the past, repeating commands like show ip arp so that I can spot when an entry times out and when it it refreshes. The repeated sequence of up arrow, Enter, up arrow, Enter, up arrow, Enter
drives me mad.
Some vendors offer assistance; A10 Networks for example has a repeat
command in the CLI specifically to help with show commands:
a10-vMaster[2/2]#repeat 5 show arp Total arp entries: 25 Age time: 300 secs IP Address MAC Address Type Age Interface Vlan --------------------------------------------------------------------------- 10.1.1.65 0000.5e00.01a1 Dynamic 17 Management 1 10.1.1.67 ac4b.c821.57d1 Dynamic 255 Management 1 10.1.1.97 001f.a0f8.d901 Dynamic 22 Management 1 Refreshing command every 5 seconds. (press ^C to quit) Elapsed Time: 00:00:00 Total arp entries: 25 Age time: Continue reading
Worth Reading: The Importance of Setting Goals
The post Worth Reading: The Importance of Setting Goals appeared first on rule 11 reader.
GE’s Irish wind farm to supply total output to Microsoft for 15 years
Getting difficult to build a cloud DC when you have to buy your own power source
Update: Brocade Data Center Switches
Second vendor in this year’s series of data center switching updates: Brocade.
Not much has happened on this front since last year’s update. There was a maintenance release of Brocade NOS, they launched SLX series of switches, but those are so new that the software documentation didn’t have time to make it to the usual place (document library for individual switch models), it's here.
In any case, the updated videos (including edited 2016 content which describes IP Fabric in great details) are online. You can access them if you bought the webinar recording in the past or if you have an active ipSpace.net subscription.
Performance Implications of CNAME Chains vs Oracle ALIAS Record
The CNAME resource record was defined in RFC 1035 as “the canonical name for an alias.” It plays the role of a pointer, for example, the CNAME informs the requestor that www.containercult.com is really this other name, instance001.couldbalancer.example.com.
The CNAME record provides a “configure once” point of integration for third party platforms and services. A CNAME is often used as opposed to an A/AAAA record for the same reason developers often use variables in their code as opposed to hard coded values. The CNAME can easily be redefined by the third party or service provider without requiring the end user to make any changes.
A stipulation that prevents use of the CNAME at the apex is that no other records can exist at or alongside a CNAME. This specification is what prevents an end user from being able to place a CNAME at the apex of their zone due to the other records, which must be defined at the apex such as the Start of Authority (SOA).
ALIAS / ANAME – The way of the future
The Oracle ALIAS record allows for CNAME-like functionality at the apex of a zone. The Oracle implementation of the Continue reading
Microwave or Fiber which one is faster ?
Microwave or Fiber which one is faster ? I will explain the faster connectivity option and some of the use cases for each, deployment considerations a bit in this post. Why latency is important for some special businesses ? Have you heard about HFT (High Frequency Trading) ? If you like the discussion points, after […]
The post Microwave or Fiber which one is faster ? appeared first on Cisco Network Design and Architecture | CCDE Bootcamp | orhanergun.net.
SD-Storage Startup SoftNAS Gets a Hybrid Cloud Makeover
It supports AWS, Microsoft Azure, and VMware, with Google Cloud Platform coming in 2018.
Application Dependency Analysis: Getting Started
In this video, learn the basics about application dependency mapping in order to uncover performance issues.
Application Dependency Analysis: Getting Started
In this video, learn the basics about application dependency mapping in order to uncover performance issues.
Don’t Be a Syslog Slacker
Syslog is a powerful tool for network analysis. Here are some best practices.
Don’t Be a Syslog Slacker
Syslog is a powerful tool for network analysis. Peter Welcher offers some best practices.
ONAP and MEF Join Each Others’ Groups, Collaborate on LSO
They will help enterprises who want to automate services across multiple providers.
SDN: Is Here to Stay
In an October 3, 2017 article published in Network Computing, titled: “SDN: Time to Move On,” Gartner Analysts report on the state of software-defined networking and advise enterprises to shift their focus. It has triggered some interesting conversation in the SDN field. As a leading player of SDN technology, we have received several inquiries for comments on the article. While the controversial title grabbed a lot of attention, it’s alarming to many and far from reality. More importantly, it differs from what Gartner reports have concluded.
From what we see in the market, SDN has already landed real use cases and built the momentum to change the production network. However, as Gartner expressed in the reports, we have seen two gaps in adopting SDN: It takes a long time for customers to adopt this nascent technology; and while SDN can be used to solve many imminent issues, it is not a panacea to all networking problems.
According to Gartner, “SDN started as a new technical architecture, but brought into light some valuable concepts that outlived the original blueprint,” Gartner VP Distinguished Analyst, Joe Skorupa and Research Director, Danilo Ciscato wrote. The article also reveals, “The story’s different in Continue reading
SDN: Is Here to Stay
In an October 3, 2017 article published in Network Computing, titled: “SDN: Time to Move On,” Gartner Analysts report on the state of software-defined networking and advise enterprises to shift their focus. It has triggered some interesting conversation in the SDN field. As a leading player of SDN technology, we have received several inquiries for comments on the article. While the controversial title grabbed a lot of attention, it’s alarming to many and far from reality. More importantly, it differs from what Gartner reports have concluded.
From what we see in the market, SDN has already landed real use cases and built the momentum to change the production network. However, as Gartner expressed in the reports, we have seen two gaps in adopting SDN: It takes a long time for customers to adopt this nascent technology; and while SDN can be used to solve many imminent issues, it is not a panacea to all networking problems.
According to Gartner, “SDN started as a new technical architecture, but brought into light some valuable concepts that outlived the original blueprint,” Gartner VP Distinguished Analyst, Joe Skorupa and Research Director, Danilo Ciscato wrote. The article also reveals, “The story’s different in Continue reading
Choosing your chassis: a look at different models
Simplicity, scalability, efficiency, flexibility — who doesn’t want to be able to use those words when talking about their data center? As more and more companies adopt web-scale networking and watch their growth rapidly increase, the need for an equally scalable and powerful solution becomes apparent. Fortunately, Cumulus Networks has a solution. We believe in listening to what our customers want and providing them with what they need; that’s why we supports the Facebook Backpack for 64 to 128 ports of 100gig connectivity and the Edge-Core OMP800 for 256 ports of 100gig connectivity. So, what exactly is so great about these chassis? Let’s take a closer, more technical look.
The topology
When designing and building out new data centers, customers have universally agreed on spine and leaf networks as the way to go. Easy scale out by adding more leafs when server racks are added and more manageable oversubscription by adding more spines makes this design an obvious choice. We at Cumulus have built some of the largest data centers in the world out of one-rack-unit switches: 48 port leafs and 32 port spines. These web-scale data centers build “three-tier” spine and leaf networks using spine and leaf “pods” Continue reading