Why isn't a subnet mask needed when routing a packet over the internet? Is it because once it reaches the destination network, then a subnet mask is applied to determine the subnetwork?

I red the answers here but frankly none of them seem to answer the question superuser.com/questions/1256044/…

Is it correct that a packet doesn't contain it's subnet mask?

Like who actually specifies the subnet mask, is it the computer sending the packet or the router?

@northerner Who said a subnet mask isn't needed when routing a packet over the internet?

@barlop I don't specify one when I ping 8.8.8.8

Well, that doesn't mean your computer didn't use one

It might test an IP to see if it's on the local network for example

i'm not sure if it would for that one.

it probably would..

it'd do a test to see whether or not you are pinging a local IP

and that test would probably involve a subnet mask

yeah it would.

By the way, if you were to ping 192.168.123.133 so any IP

you didn't specify a subnet mask there did you

But an Ethernet frame doesn't contain a section for a subnet mask.

hang on.. So you didn't specify a subnet mask, regardless of whether the IP was to the internet or not. see my ping example

Routers have configurations for subnet masks

Packet would be more accurate than ethernet frame in what you just said.

So routers are the ones that know the subnet mask? I wasn't really sure who knew it

and indeed a packet doesn't have a subnet mask in it.

An ethernet frame doesn't have anything to do with IP addresses even.

packet is a better term in that it can be used generally to refer to the whole thing. And still no subnet mask there.

Your computer also specifies a subnet mask too

ok so it's handled by OS but not the application?

OSs are everywhere. An application could handle a subnet mask too

even a router has an OS

Anybody that wants to check whether an IP is on a particular network.

would use a subnet mask

My point being if I knew someone's IP address that would be enough to contact them. How is that possible because don't we need the subnet mask to know which subnet they are on?

well, all your computer needs to know is , is it local or not. If it's not then send it out.

A home router just needs to know, is it for local, or is it for the Internet

OK that makes sense

Each router needs to know about the subnets directly connected to it.

just going to go to the toilet 1min

btw there is a good book by wendel odom called networking first steps.

Where/How can I download this update for Windows 7? KB4457144

ah thanks! I went there before but didn't see the download button before!

Anyone up for some jazz music?

twitter.com/i/status/1331663255299891204

I did not expect Jazz on bagpipes

reddit.com/r/anker/comments/k1nxj5/…

@Hennes Jazzpipes, you say?

Oh that clip

I understand she's quite the talented multi-instrumentalist

clip was from NY a few years back?

First time I saw it

tons of stuff out there I never heard of.

I only saw it recently too

every day can be one of those XKCD discovery days

Heh.

Though some day there will be too many xkcd numbers to remember

Fortunately there's always the wiki :D

I always wonder if anyone's tried browsing his site in a browser conforming to his strange, conflicting recommendations

> xkcd.com is best viewed with Netscape Navigator 4.0 or below on a Pentium 3±1 emulated in Javascript on an Apple IIGS at a screen resolution of 1024x1. Please enable your ad blockers, disable high-heat drying, and remove your device from Airplane Mode and set it to Boat Mode. For security reasons, please leave caps lock on while browsing.

lol

grin. I did not notice that.

@bertieb That's actually been around for a long time...