Are you a Linux user or Windows user? Netstat command allows you to examine your system's routing table. For example, if you are on the command prompt using Windows you can execute netstat with the -r switch by typing in "netstat -r" and the result of that command will show you your system's IPv4 and IPv6 routing table. IPv4 is the older version of Internet Protocol (the IP in IPv4 stands for Internet Protocol) which is commonly used today but companies and many organizations are slowly and gradually moving over to IPv6 because we are running out of addresses to use in IPv4. Plus, IPv6 is more secure than IPv4. IPv6 is written in base 16 hexadecimal rather than base 10 decimal. IPv4 on the other hand is written in base 10 decimal.
Internet Protocol has to do with routing packets over your network and the internet whereas TCP (Transmission Control Protocol) is a heavy weight protocol that guarantees all destination nodes receive all the packets you send that destination node. It has to engage in a three way handshake with the destination node to establish a connection with that node before sending it packets, whereas a lighter weight protocol like UDP does not. UDP is a much faster protocol for sending packets over the internet but it's not reliable as not all the packets are guaranteed to arrive like they are using the TCP protocol..
Whereas TCP is a heavy weight protocol that guarantees all the packets will arrive and if for some reason it does not receive all the packets it will ask the sending node to re-transmit the packets it did not receive. This makes the TCP protocol more reliable than UDP but slower. So bascially you are making trade offs between speed and reliability when using TCP and UDP protocols when transmitting packets over the internet. So, when you see TCP/IP what that stands for is Transmission Control Protocol/Internet Protocol. Transmission Control Protocol is used to guarantee that all packets are sent are received by the destination node and Internet Protocol is the protocol used to choose the routes for the packets to arrive at the destination node. Make sense?
You can use netstat to also check for open ports on your computer. The more open ports you have on your computer, the greater the attack surface your computer is for a hacker to attack your computer. So, you don't want to have any ports open on your computer that don't need to have open as that is making it easier for hackers to attack your computer. You only want to have ports open that you are actually using and need to have open.
Otherwise, you want to close those ports. You can have TCP ports and UDP ports open. So, if you are using command prompt on your Windows system, you can type "netstat -a -n -o" and it will tell you what processes (applications) are listening to what ports. Many of those processes are listening in on localhost which in terms of IPv4 translates to 127.0.0.1. Closing ports that you are not using lowers your attack surface for a hacker to attack you on.
You can read more about netstat here where it gives some examples using Linux: https://geek-university.com/linux/netstat-command/
Edit: I see, you are using DOS which is the command prompt. I missed that point when I read your post initially. You can also use PowerShell on Windows. PowerShell is Windows equivalent to the Linux Bash Shell and is pretty powerful.
"Just do one thing or the other, don’t try to be two people at once." -Arthur from Red Dead Redemption 2