Best video I've actually seen on this. For those that are going to use this you can try. For all others wanting to have an Idea on syntax -N is to create new policy -I is insert into the policy chain(putting at top) -J is to jump to policy chain -L list policy (-n with out name resolution , -v verbose) -A append to end of policy -s source ip/host -d destination ip/host --dport destination port --sport sourceport --dports 0:65535 multiple ports --src-range/--dst-range 192.168.1.100-192.168.1.200 ip ranges
I searched the Internet a lot for such a tutorial. This is the best online computer networking tutorial I think. Please continue!!! You could tell us something about Protocols eg (in general and some important Protocols in detail)
Your channel is so damn good man, really easy to learn and understand. I don't have the words to express it anymore. You should have like a million subs, probably the best teacher about computers here on RU-vid :]
Thank you for this tutorial. I'm trying to learn how to setup a mail server. And, it's not so easy, coming from a Windows background. But, I'm trying to get into Linux and learn. So, this simple tutorial about iptables is very helpful for me to build up the basic knowledge. Again, thank you. You are a very good teacher.
+Ryan Zhou I just watched whole 40 videos within 2 days :D got some problem understanding some terms in somewhere but no problem will be clear in some other tutorials ;)
Hey Bucky, I have seen all your vids in one session. Thanks a lot mate. Great job and effort, easy and smooth. Head up and waiting for your next vids. > liked and shared!
1:20 Actually there are five chains, not three. But you're looking at the filter table, which only has those three available. Look at the mangle table and you'll see all of them. There are more tables (five) and more chains (also five).
This specific example only shows blocking IPs within your local network not WAN... JUST to clarify 192.168.x.x is standard for LAN... but the pattern matches... Also for the example with email, this would only apply if you were hosting your own email server and setting filters to the email server itself, typical email has this feature built in to email settings under "filters" "rules" or similar. But the pattern shows network filtering.
+Juno Lee He's had a lot of years to learn. Before each video he probably researches it from text tutorials to refresh his mind, because I doubt he can remember everything in all his RU-vid videos.
blocking port 25 will only allow you to drop packets going out haha. SMTP is for sending mail gotta block IMAP or POP3 LMK if im wrong only been into computers for 2.5 years
Dude, why did you stopped your networking tutorial here! we want some more of this. at least cover the FORWARD of iptables. you gave the best understanding of iptables and so for networking. please!
Bucky, I got one question. Previously in your videos, you mentioned about setting up firewall rules at the linux server level. Here you showed that you are setting up at the PC level. So when you are in a network with a server/pc's how does it work, do you need to set up firewalls seperately at PC level,server level for each and seperate node or just set up the firewall rule at the router level
first, its not pc/server, more like client/server. it depends on what you want. for example if the client and the server are on the same network, you have to set the firewall rules in the server because they reach each other directly. if the client traffic comes from other network, you can filter it in the router(gateway) and also in the server too. Usually i filter traffic on host level every time, and if I need it (for security reasons) I also filter it in the gateway too.
i beg you please tell about The Network layer Network layer concepts, design issues, static and dynamic routing algorithms, shortest path routing, flooding, distance vector routing, link state routing, distance vector routing, multicast routing, congestion control algorithm, internetworking, Ipv4
Blocking your GF's IP doesn't make sense at all. That wouldn't stop her from sending you anything. Her devices do not initiate direct connections to yours, with most chatting/messaging/emailing services. You would for example need to block her IP on gmail servers if that's what she uses to send you emails. Edit: blocking incoming connections to tcp/25? Seriously? The SMTP server is not on your machine...
I'm not any great with networking, but is it by any means meaningful to block the gf's IP-address, considering you almost certainly haven't set up your own mail-server at home. You most likely use some commercial like Gmail for instance. I mean you will not get unmasked traffic directly from her, like Messenger/Skype calls and stuff like that, but she can still message you wherever her data doesn't enter your computer directly, but just a datacenter like Google's mail server.
Does anyone know what's the point of ufw (in the console, not the graphical interface) when you type almost exactly the same thing in iptables? I recall that it was supposed to be simpler but you type exactly the same rules in both programs
How I will know the X person internet router IP address, from which he/she is trying to send a message? Also while blocking someone, should I use their device private IP address or Router public IP address? I am very new in this , so maybe these questions can be sly
