Linux




tcpdump now shows interface names in its output, finally

Table of Contents Resources Actually it is not news - it happened with the new 4.99 tcpdump version starting 2 years ago. But most binary distributions still lack this version. So, I had to install it from sources even on the RHEL 9, the newest version. The steps are simple …



Network MTU maximum size path discovery (PMTU) testing with ping

MTU (MAximum Transmit Unit) plays central role in available throughput. And while with the Internet the maximum size isn’t going to surpass 1500 bytes, on MPLS/IPL/etc lines, owned by 1 provider, it is possible to get better MTU. THe easiest way to test for the maximum size …



GNU tar archive tool reference by example

Table of Contents Archive and gzip-compress the current folder with tar Archive and gzip-compress the current folder using maximal compression possible Set compression level as the GZIP environmental variable for gzip Set compression level by piping tar output to the gzip Use -I option for modern versions of tar Archive …



Aruba and HP switches debug and diagnostics commands cheat sheet

Table of Contents General Health Logs Interfaces VLANs Daemons Real-Time Debug Spanning Tree Protocol (STP) Routing Info Static BGP OSPF LLDP & MAC & CDP PoE DHCP NTP VSF (Virtual Switching Framework) Note All commands were tested on HP/Aruba 5400 switches (specifically 5406Rzl2), but will work on any model with recent …



How to request Google, Cloudflare, and OpenDNS/Umbrella DNS servers cache clearing for your domain records

It is rare for these well-known DNS providers to cause problems to your domain records, but everything is possible. More often though, you may need to refresh some DNS record of your domain sooner than its TTL expires. Below you will find links how to do so for the aforementioned …



Nfdump netflow/sflow cookbook of examples

Table of Contents Introduction Start nfcapd netflow collector in a daemon mode listening on port 5001 with all extensions enabled and saving received netflow data into the named folder NFS-cisco-rtr. Accept netflow records only coming from the sender with the IP of 13.13.13.137 Read and print all …



AWS cli cookbook

Get a list of all the buckets under user account Recursively list contents of a given bucket yurisk.info Recursively list contents of a given bucket printing sizes in a friendly format List contents of a bucket, add summary for number of objects and their total size Get access-list associated …



RAD ETX 203, 205, 220 debug and information commands

Table of Contents Cheat sheet of debug commands Examples show configure port summary show config port eth 4/2 status show config port eth 4/1 statistics Measuring the traffic rate passing the interface Run ping between 2 ETXes show config system system-date show configure flows summary brief show configure …



Curl examples cookbook

Last updated: 19 December 2020 Get coronavirus/Covid-19 statistics for your country, real-time or historical Force curl not to show the progress bar Download a web page via GET request setting Chrome version 74 as the User-Agent. Download a web page via GET request setting Googlebot version 2.1 as …



MRV Optiswitch OS904 OS906 OS912 debug and diagnostic commands

MRV Communications (acquired in 2017 by ADVA Optical Networking) is an Israeli company known for their optical network equipment, most notably their Optiswitch Carrier Ethernet Switch series. The switches (OS904, OS906G, OS912) are not available for purchase from them anymore, but if you work for a telco company, you surely …