The ramblings of a computer geek
Sometimes you have some kit that is just old and isn’t supporting the recent (and secure) key algorithms, if you need to connect (with some consideration of the security implications) you can use something like the below. The “-v” means verbose, you can see when connecting what the end point is offering, then you can […]
More...IPerf is a tool that can be used to measure the bandwidth and quality of a network link. Its a useful little tool, so I’ll introduce some of the basics of how you can use it to perform some tests. Bear in mind this is not an exhaustive guide, there are many tweaks that can […]
More...If you need to perform a Ping scan of a subnet, you can use the following command, its quick and dirty approach, although its not really that quick when it comes to actually running. The below will scan the subnet 192.168.1.0/24, from 192.168.1.1 to 192.168.1.254. If you want to speed things up a bit, you […]
More...Allow a connection from a particular remote IP address to any IP address on the local machine on a specific port (TCP & UDP). Verify with:
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Setting up network bonding between two 10Gbit NICs within a physical machine; this assumes Active-Standby bonding so a link down event on one NIC will cause the other to become Active, no LACP or switch side configuration is required in this case. The documentation assumes you are running under root, stick sudo in front of […]
More...Creating a user account with a home directory and setting the default shell as BASH, can be done as follows, add “sudo” to the front as required. If you need your account to have sudo rights, you can specify the “sudo” group upon creation, as follows:
More...A quick example on Ubuntu Linux 22.04 LTS. I had the need for a particular user to have “passwordless” sudo ability. Its not best practice to do this, however if you are restricting the command or commands that a user can run with “passwordless sudo”, you are balancing functionality and security as well as you […]
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SNMP (Simple Network Management Protocol) is a protocol that can be used for monitoring and managing network connected devices. Personally I use it primarily for monitoring, it is a useful way to interrogate network connected devices for information about their status. For example querying to identify if a power supply has failed on a switch, […]
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NagiosXI has a REST API that can be used to add, edit and remove objects from the configuration. Full details of the configuration and use of this can be found on your installation at: http://nagiosserver.domain.com/nagiosxi/help/?xiwindow=api.php (or you can find it through the Advanced Configuration menu). Each user has an APIKey which can also be found via […]
More...A quick guide to setting up SSH Public Key Authentication. SSH Public Key Authentication means you can authenticate to a remove server via SSH without needing to enter your username and password. Instead you create a public-private key pair, then place the public key on the target server. Then when you SSH to the server […]
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