Per the manpage:

The arp tool manipulates or displays the kernel’s IPv4 network neighbor cache. It can add entries to the table, delete one or display the current content. ARP stands for Address Resolution Protocol, which is used to find the media access control address of a network neighbor for a given IPv4 Address.

You can use the arp command to list all of the devices on the local network. It is often useful to find the identities of hidden devices on your network. For example, if you just plugged a Raspberry Pi into your local network and need to find its IP address in order to connect to it via SSH.

My most frequently used netstat command with parameters for checking port (active internet) connections is:

$ netstat -tulpn

You can also pipe the output to grep to filter for specific ports or addresses.

Here is a brief listing of some of the many options:

$ netstat [options]

To find details about the virtual network you can use these commands:

root@slacker:~# virsh net-list Name State Autostart Persistent -------------------------------------------- default active yes yes root@slacker:~# virsh net-info default Name: default UUID: 14a90f27-9a85-42ca-b434-6ce6c142690c Active: yes Persistent: yes Autostart: yes Bridge: virbr0 root@slacker:~# virsh net-dhcp-leases default Expiry Time MAC address Protocol IP address Hostname Client ID or DUID ------------------------------------------------------------------------------------------------------------ 2023-07-22 16:18:45 52:54:00:dd:7b:62 ipv4 192.168.122.216/24 centos7-bbk -

Assuming your system still has netstat installed (Slackware 15.0 does :^), you can summarize the TCP connections on you host using the following command:

$ netstat -ntu|awk '{print $5}'|cut -d: -f1 -s|sort|uniq -c|sort -nk1 -r 3 52.50.230.xxx 3 104.18.27.xxx 3 104.18.26.xxx 2 205.166.94.xx 2 192.168.1.xx 2 142.251.40.xxx 2 104.18.13.xx 1 74.120.9.xxx 1 66.255.245.xxx 1 54.154.65.xxx 1 52.96.182.xxx 1 45.56.116.xxx 1 45.33.73.xxx 1 34.117.65.xx 1 20.190.135.xx 1 192.168.122.xxx 1 192.168.1.xx 1 172.253.63.xxx 1 162.159.61.x 1 162.125.21.x 1 142.251.40.xxx 1 142.251.32.xxx 1 142.251.16.xxx 1 127.0.0.x

If netcat isn’t available on your machine and you don’t have the priviledge to install it you can use this trick to test if a port is open or not. It will throw a connection refused message if a port is closed.

$ : </dev/tcp/127.0.0.1/80

And you can use it in a script like this:

(: </dev/tcp/127.0.0.1/80) &>/dev/null && echo "OPEN" || echo "CLOSED"

In case you misplaced your wi-fi password you can recover it very easily using 2 commands on Windoze:

Open the Terminal or PowerShell

PS C:\Users\user> netsh wlan show profile

The output will be similar to this. You need to obtain the User Profile of the connection that you’re interested in:

Profiles on interface Wi-Fi: Group policy profiles (read only) --------------------------------- <None> User profiles ------------- All User Profile : ROUTER21 All User Profile : 4YWD8-5G All User Profile : 4YWD8