Hi nice bit of coding but there is a number of errors in your networking description. Firstly the modem is not where your public address will sit it will be on the wan interface of the router and the router is in fact firewall as it will hide the private addresses behind the public address. You are dealing with tcp ports the is 65535 ports full list en.m.wikipedia.org/wiki/List_of_TCP_and_UDP_port_numbers And the number you are seeing with the received message on the server is in fact the source port. Also you would not run your server on the modem it would be run inside your net work and using Nat you would forward connections to the server via the router but this would be bad idea on a home internet connection as the router will not be secure enough as you normally what to this via a DMZ.

Spent the last two weeks trying to understand why my simple server - client simulation was not working ; I cannot count how many tutorials and searches I have waded through - wish I found you sooner - I am definately sharing your channel. Not only did you fill in some seemingly simple blanks your explanations of everything were thorough and clear and showing your process all the way through. There are so many ways to trip up if you are new to working with sockets and your video prevents just about all of them. Thank You!!

Thank you Tim!!! I have been watching all your videos since 4 months ago, i love them all because you explain everything so good. I was so close ending my coding career, but you helped me up from being stuck on worthless beginner videos. And because of this video, i subscribe, like and share this video. I almost never do this on youtube, again, a HUGE THANKS!!!❤❤

Thank you for this incredible content! I started working on an online ccg game with what you showed in the online python multiplayer game. This tutorial make it much clear how the connection worked. Thank you again for the tutorials and keep it up with the good work!!! Best to you from Argentina!

Thanks for this video! You always are able to explain things really thoroughly and succinctly. I've been working on my web related Python skills, so this was a good overview of something I needed to learn.

Despite the errors, this video is incredibly useful for getting a head-start on getting a python server running. My degree courses never really taught me python let alone sockets, so this has been a MASSIVE help getting me going with a python server I need to have interacting with a MySQL database for my senior project.

What you guys think of that intro ;) And code is available here: techwithtim.net/tutorials/socket-programming/ . Also kindly note that there are some errors in this video, I've pinned a comment that points out some of the major ones. Sorry guys, I'm learning too and will try my best to avoid such issues in future videos!

Hey Tim! Just found your channel today, I was looking to implement websocket to run distant function and I have to admit I'm impress by how you manage to give enough informations so we can get started quickly without falling in the "too much informations trap". You're an inspiration for me! Thanks this tutorial is what I was looking for!

I really like the way you taught. You always start with the big picture so everybody can get a basic understanding about the topic then go to the minor details. Not to mention that your explanation is so intuitive and simple that I think even an 8 year-old kid could understand. Keep up with the good work

Great tutorial. Recently learned how to deal with multi threading and created a chat app, and I can say socket programming is really cool.

This was a really good video Tim, look forward to part 2 !

You are a life saver. I have been trying to study it for the past 3days and boom here you are

The flow of your program and explanation was SPOT ON ! Just Awesome !

Been eating up the python content lately, finally a guy with a decent Mike and understandable explanations

love the new intro tim. Boss mode activated

This is such an amazing tutorial. I will read up on the technical details myself, but the programming part was on point. Thanks a lot for the efforts put into making this video, Tim!

Tim, thank for the video and great explanations. I recently was on my second interview with a FAANG company, and even though I am not a programmer and stated such as I was considered for communications position. I was knocked out of the running from the position as I did not know how to open a socket (on a satellite, lol! Will not be done unless they are the owner or operator.) using python. So I search the Internet for the solution. I found that your video and explanations were what I needed. Thanks for your tutorial, I can now answer a questions about opening up a socket using python!

31:06 [WARNING]: For those of you on Windows, if you get an error saying "An operation was attempted on something that is not a socket", then make sure your "conn.close()" operation is not occurring within the "while(connected):" loop.

Oh gosh! This is super clear! Thank you for this tutorial! *THUMBS UP*

Covers perfectly the basics of sockets, good job!

The best and most comprehensive socket programming (for beginners of course) tutorial I've ever seen. Thanks to you, I understood socket programming after 6 years🧡🧡🧡🧡

Hey buddy I am really big fan of yours you are really a great teacher I've learned a lot from this channel. Thanks man keep rocking from India🙏🙏🙏

Awesome video. A little late to the party here. At 28:00, HEADER = 64 bytes means the header can take up to 64 digits as chars in a string (1 byte / char). That means your header + payload string altogether can have a maximum character length of 9999999999999999999999999999999999999999999999999999999999999999.

Intrinsically, i am very impressed by your work. Not to mention that, you always consider us as you and or come out with frequent encounter issues like setup, or common technical issues with clear explanation. Glad to have you as my coach toward my programming journey, appreciate your work!!

Holy shit thanks man, I really appreciate how you explain everything thoroughly. like some people would skip the networking parts and assume most people who want to write a socket program know this. Really well done being thorough and not skipping anything just in case someone has some information gaps. thanks!

I am still a beginner in Python but this was really easy to understand. Thank you Tim!

Thank you Tim , i will just add some infos about making a public socket over the internet : - on the server side , you will have to add a new rule of type port being used to control connections for TCP / UDP .. mostly u will be using "tcp" in both the outbound and inbound rules. - probably run the scrip as admin just to avoid possible "Permission problems" - on the Client side u just gotta whitelist the client side program/app/script to allow all sending data over a tcp port .. else just go and add a rule as an inbound rule . - be carefull , hackers might actually exploit that to access your private stuff / mess the server , so unless you know what your doing .. practice just with trusted friends or alone . - do not forget setting up port-forwarding on the router , so instead having clients reaching that port exmpl "1337" on the modem public address , they will be redirected to local_ip:1337 instead of public_ip:1337, hopefully u get that. - I would suggest using NO-IP (ddns aka "Dynamic domain name server") instead of hardcoding you public ip directly . finally , feel free to subscribe I'm making such vids maybe not as good as Tim's but we're getting there.

@Tech With Tim Was cool watching this. I taught this to myself 7ish years ago and built a little client server chat app (a bit more functionality than this) overnight. Still one of my favorite projects (haven't done much coding in the last 7 years). It was pretty cool seeing this all summarized in under an hour, might jave to do some more fiddling with sockets. Also assume you are a fellow Canadian since you are on the Roger's network.

Good tutorial, you are right (depend on the configuration you have) you can have a public ip in the company modem and a private ip in your local router router, that is a double NAT, it have pros and cons as all configurations. You can use TCP, UDP and others protocols depending on the layer. etc. Thanks for the tutorial.

SOCK_STREAM is for TCP - which is the transport protocol widely used, not some vague thing meaning "streaming data" Other options include ones for UDP

Since you didn't know: 8 bytes can be a number up to 18 quintillion, or 18 with 18 zeros, which, when used as a header could represent a 18,000 Petabyte message. So a 64 Byte header is a bit overkill since it's 18 quintillion to the eighth power (6 x 10^57).

Thanks man ! I was really trying hard to make threading in sockets, this resolved all of my queries

your videos makes curfew easy for me big thanks to you keep going , much respect 🌹

10;45 start of programming explanation, first part was networking lan/wan info, no need to change the firewall on the client computers ! you might need to open a port range on your router and redirect that to your server and then change the firewall rules on your server to accept requests coming from your router.

Hey Tim! What about a series where you set up a server and client for like a chat or even a little game? A live stream day perhaps? Great content, keep it up!

Thank you! I've been struggling with this topic for a long time and you helped me understand every bit of it :)

The python sockets tutorial i never had and always needed. Thank You

Using select is a good choice for asynchronous servers.

Great Job Tim!!! , Love from Concordia University Library , Montreal

Wow ! I love this video ! A new way to speak quietly in class

The SOCK_STREAM means connection oriented TCP protocol, for all that wondered :D ( 17:53 )

Nice intro, please continue the socket programming tutorials, don't jump into another topics. BTW do you have python threading course?

Excellent video ! Only a few approximations at the start when discussing networking but that's not a problem since this is not really the main topic of the video. Python is on point ! Congratulations !

It really helps !!! Thanks a lot !! I totally like the way you explain how the whole thing works look forward to more your videos about python ~

35:00 In VSCode yes you can run multiple interpreters - in the terminal, you can plus +, and then the box next to the + to show both interpreters

Hey, great tutorial! But... while making a project of my own using sockets, I found something interesting I think you should've included: it isn't a good idea to call sockets' send() method more times than needed, because it really affects how much data you can send per second. So, instead of sending the header and the message separately, it's better to do "socket.send(send_length + message)" (once they're both encoded, ofc). Found that out after making a simple game using sockets with pygame, where each client's position would have to be sent to the server as fast as possible, and then sent to each client once more. Initially, the clients' positions updated quite slowly; after that change, they updated in almost realtime. Love your channel!

Yesterday I though about a new programming project and I came to the conclusion that learning something about sockets would be a good idea. I guess I am going to start today, thank you ;)

Thank you! with this video I now have a good understanding about sockets programming, before I was so confused about it, I like your detailed explanation. well Done!!!

thats a really nice intro!

0:00 to 10:42 is basic networking, modems and and IP's. Skip to 10:43 for the coding.

Totally awesome Tutorial .. and that's what the reason why i always search for Tech with Tim if i want to learn something... You post awesome content..

I got inspiration from your chatting website. I even made frontend of it, and i am learning backend from you.. Thanks for everything

My entire life changed when I meet you in UKposts. Again and again.

*If you can't see your server from outside of your local network:* Most frequent problem you may face while making server reachable over the Internet is port-forwarding. In most cases you should go to your router settings and forward your outer port 5050 to local port 5050 of your machine you running the server on. Cuz people who trying to reach you with your public IP litteraly will reach your router. So in situation from this video forwarding rules will tell router that if someone will try to connect to its 5050 port it should send 'em to 5050 port of 192.168.1.26 machine and not Macbook.

I love this guy. He explains well and makes things not complicated. As a beginner, I'm glad that his explanations and demonstrations are clear, and I actually know what the hell is going on. Thank you

Thank you so much for this amazing tutorial ,honestly In this 50 minutes tutorial I've learned more then one year at University you are great 🙏👍

I'll need to see this more times. ;-;

Hello Tim, just want to add that socket.gethostbyname(socket.gethostname()) might return 127.0.0.1 on linux machines if there is an entry in /etc/hosts file. Removing this entry from the hosts file may cause other installed programs to break, the only reliable way (that I found) of finding the local IP is using a DNS ping. s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) s.connect(("8.8.8.8", 80)) SERVER = s.getsockname()[0] s.close() print(SERVER) Hope this helps.

Hi Tim, love your vids. I would like to see a video on Ctypes one day if you get the chance (I.e. wrapping DLLs in a foreign language in python) Keep up the great work, you’re killing it.

Man, you're saving my life a lot! Thanks for the tutorial!

Hey man, any recommendations on some keywords to search for learning about implementing a good level of security with sockets?

Are in Canada separated Modem an Router still a thing? In Germany, Finland (and most other European countries) the modem and the router have been build together in one device. Companies sold them as "Router" but they have build in modems.

Literally started my python experience with this video

Awesome Tutorial, looking forward to part 2!

Hey Tim how long did it take you to learn the basics to have the ability to build things with python?

perfect tutorial and thank you so much, looking forward to seeing more episodes on this topic

Really fascinating!!! I can make my own server and have client over the public internet or local network send and receive messages across the server and the clients!

Hey, tim..great work...But I tried using the public IP address and it says af_inet doesn't support this address family...what do I do??

When ur coding socket belike : socket = socket.socket(socket.socket(),socket.socket.socket) Edit = 69 likes 😈

one of the best socket tutorial on yt

youre the IT goat tim thank you for your module showcases

The tutorial was really great and I did learn the basics of how to mess around with sockets. I do however have one complaint and that is the method you showed on how to make the server available on the internet. Having the server socket run on the Public IP would never work because multiple devices that are connected to your network share that same Public IP. How would the router know which device to forward that traffic to? I looked around on the Internet and Port Forwarding seemed like a viable and easy solution but unfortunately that didnt work. So how do we actually get our server socket on the internet?

Not only did I just learn a ton of stuff(it is hard for me to concentrate for a longer periods of time) but I also learned about threading AND - I did on my Linux machine, I am so happy it worked and I understand most things if not everything now! Thank you for existing and doing tutorials like these! Just a quick question - how would one encrypt messages(end-to-end?)? I presume I can make up random letter alternatives for my program and like replace each letter within the messages with another one and later reverse it, but I suppose that it would be not that hard to decode.. Yeah f*** Trump and his no end-to-end encryption, I am not in America and I am against that either way.

The best programming channel I seen ever is here😀

Thank you Tim, that was an awesome tutorial really helped!

34:15 age-restriction this man. 😂😂 oh yeah tim. You are connecting to something.

You only need 4 bytes for a message header. This will let you represent numbers up to 4 bytes * 8 bits = 32 bits ^2 = 4,294,967,296 (integer), which is more than enough for chat messages. Given the sometimes small buffer sizes of TCP/IP layers, 64 bytes for a length header is excessive. But not only that, it's _dangerous!_ As shown before, you can use 64 bytes to represent _astronomical_ numbers, and there's no way in _Hell_ that a chat message will _ever_ be that long unless you sent only noise ... for years(!). But by exploiting a header with so much bloat, it becomes much easier to crack such a naïve implementation of a chat client to construct third party _Denial of Service_ (DOS) attacks. In other words, if any of these bad implementations are found in the wild, they're exploitable by evil hackers. So let's say, hypothetically, that a large TCP/IP buffer is about 1 Mb RAM. That's 1,048,576 bytes (and buffers can be much smaller than that). If you use just empty messages from a bad chat implementation, which is using headers that are 64 padded bytes long, then it only takes 1,048,576/64 = 16,384 messages to launch a successful DOS attack, as that is the amount of empty messages you need to fill the buffer. Now, that might seem like a lot but it's really nothing to a computer, so it would be a fairly trivial thing to implement, and especially if the chat application has such a bad design flaw. This is why most systems employ other defences against such things, but all it takes to break the first wall, is to infiltrate a poorly programmed chat application. Worst of all, _you'll_ be blamed for it, and not the hacker, since the hacker is merely exploiting your bad code to hide his identity while performing the attack.

THIS IS AWESOME! you just solved one of my biggest problems with coding my messenger, thank you man ❤

Thank you Tim for this video, you made it simple for me!

For reference in regards to ports: - Well-known ports: 0 through 1023. - Registered ports:1024 to 49151. - Dynamic ports: 49152 to 65535 You will typically use an available port in the registered range such as 8080 or 4443, assuming its not already in use.

i have that error client.bind((SERVER, PORT)) OSError: [WinError 10048] Only one use of each socket address (protocol/network address/port) is usually allowed

one of the best videos about socket and thread

If your are getting the ConnectionRefusedError: [WinError 10061] error try changing the code on the server file from: SERVER = socket.gethostbyname(socket.gethostname()) to: SERVER = "your IP adress"

Great video :) It's weird but when I try to bind my public IP adress it raises an error 'Can't assign to requested address', do any of you run into the same issue ?

Okay I'm a CS major taking Net computing and you are a better teacher than my teacher. Thank you for saving my life!

That is a great video! well explaind and really good quality of sound and video. Thank you!

how did you send the file. Is there a way not to have python installed on other devices?

ValueError: invalid literal for int() with base 10: 'hello world' still happening need help i used his fix and its still happening

hi Tim I really enjoy your videos, you're probabely the YT channel which is by now the most usefull in my programming journey ! I have a request which is : could you make videos as this one but in a more general scale, I mean not based on a specific laguage but just explaining the purpose of a header a handler and all this kind of stuff, because in most tutorial people use those fuction et show what to write but often I dont understand the purpose of each fuction like "what's a writer... how it works... Sorry for my poor english

Omg, what an intro! keep it up man really nice videos

Hey Tim, when i tried to ran the server.py the second time it gives the following exception: OSError: [WinError 10048] Only one usage of each socket address (protocol/network address/port) is normally permitted When I changed the port, I can run it. But then I cannot run again on both those ports. Can somebody help me with this?

"Hey, I moved to the right." *moves left*

5 stars. Wow high quality. Nailed tcp socket connect

thank you you the way you explained, don't know how but solved my problem successfully built the GUI server client i was trying

how do you get the "run" button on vscode

youve tought me a lot about networking. Thank you for this video.

This is the first time I am learning Python and it is really helpful

Tim,though u are not good at network but it was really cool for beginners like me to understand ❤️thanks a lot for being our teacher 🙏🏽🙏🏽

Liked the way you explain things, easy to understand and implement. Thank you Just a quick hint VS code does allow multiple Terminal, to use it click the window button left to the trash.

I am relatively new to Python and this information was really useful