If you are trying to update ubuntu respository and getting error: W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/trusty-backports/Release.gpg Temporary failure resolving ‘us.archive.ubuntu.com’ just check the DNS. Set the Google DNS (8.8.8.8) in /etc/resolvconf/resolv.conf.d/base echo "nameserver 8.8.8.8" | sudo tee /etc/resolvconf/resolv.conf.d/base > /dev/null then sudo service resolvconf restart After this procedure, I was able to resolve hostnames and sudo
What if we have logs of a server like apache or syslog server and we want to get average time from timestamps of all rows. How can we do it? Basically, we need to filter timestamp (column-8) from each row and just find its average. Below is the screenshot of the problem. (click on the
Sometime back I caught up in a situation where I need to kill multiple pid invoked from same process. So, all process have same name Assume, process invoked for “vim” editor. If I have 20 “vim” process running and I want to kill all of them, what’s the best way to do it? #There are multiple ways:
Tcpdump is a command-line based packet capture tool like wireshark which is GUI. Capture all traffic on ethernet interface: $tcpdump –i eth0 2. Filter by host IP-address: $tcpdump host 10.0.2.15 3. Filter traffic by source and destination ip-address: TCPDUMP filter by source and destination: $tcpdump src 10.0.2.15
If we are working on production servers, we come across situation with performance issues like slowness in web server, particular service is not working, 5xx response codes to the users. Below is the basic list of steps you can take to find the issue. We assume that atleast ssh is working in the server, if
CURL is a command line tool used to transfer and retrieve data in web. Let’s have a look at few of the useful options while debugging web issues. Basic syntax $CURL <Options> <hostname or ip-address> Options are optional. Hostname and IP-address can be interchanged depends upon the options we are selecting. First example is to use
Introduction Most of us take modern day Ethernet for granted. This is probably because it is what many of us have always known. This is especially true if you are like me and got into this crazy business . Today, Ethernet is a globally recognized and widely used standard. It is used in networks all
The ip unnumbered configuration command allows you to enable IP processing on a serial interface without assigning it an explicit IP address. Using ip unnumbered interface, we can “borrow” the IP address of another interface already configured on the router, which conserves network and address space. In other ways, when serial or any other
Here is an interesting video for Network Engineers have experience on Cisco devices and want to learn Arista switching. I tried Arista vEOS on VirtualBox. Cisco VIRL, GNS3 and UnetLab also support Arista image.
Here are the steps to solve Docker 403 forbidden error:
$ docker login --username= --email= https://index.docker.io/v1/r
Error response from daemon: unexpected status code[403]: <html><body><h1>403 Forbidden </h1>
