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I think you probably have a lot of valuable knowledge that should be written down. What knowledge about networking do new hires lack? How does one get comforta

I think you probably have a lot of valuable knowledge that should be written down. What knowledge about networking do new hires lack? How does one get comfortable with networking? I'm an undergrad, and my plan for that topic was to learn how to read pcap files and also learn to use wireshark to monitor my network.

Damogran6 4y ago
it's all so ad-hoc and random. Firewalls have expensive and cheap operations...passing a packet? Cheap. Opening the packet and rewriting the header? Expensive. That can be leveraged for evil. How do you even organize that kind of random trivia?
- Alekhine 4y ago
  I don't know much about firewalls. I wasn't aware they could alter traffic, for example. What do you mean it can be leveraged for evil? As for organization, I just dump everything I learn in a markdown file on that topic, then look for structure later. So I would just open a file, call it `firewalls.md` and write that down in there. You can accrete a lot of written knowledge over time this way.
  - ilc 4y ago
    They can be used for all types of stuff. Imagine two companies merging. They both used 10.100.0.0/16. If you were in one of the companies wouldn't it be nice if the other re-ip'd? ... Guess what.. they won't and you don't want to. So you make a box, that turns your ips into 10.101.0.0/16 and theirs into 10.102.0.0/16... and you leave your IPs alone :). Yeah, some things won't work across that bridge. But it'll get you started. Firewalls can do really, really evil stuff. DNS? Yeah, we'll answer ALL dns queries.. Even ones you send to 8.8.8.8, or 1.1.1.1... The BOFH playbook is large, and varied. :)
  - Damogran6 4y ago
    Networking, not just firewalls, is about looking at a packet, opening it up, and either passing it along to the next link in the chain, or making a change to (typically) the header and sending it along. There's a TTL or Time To Live value to make packets eventually die, otherwise, packets could potentially move from router to router forever. So at a minimum, your firewall, or router, rewrites the header to Decrement the TTL by one with every hop. Which spawns a really interesting thought experiment that results in the creation of the traceroute utility.
- Jtsummers 4y ago
  > How do you even organize that kind of random trivia? Having been slowed down in the past by this kind of thinking: My advice is don't. You throw the information together and forget about organization (as in a final presentable organization), you just write. Use systems like tags (metadata) to attach concepts and use queries on the tags to find related things. As you build up the knowledge base you can start organizing it more properly, into real essays or chapters and sections. Not all knowledge is amenable to pre-organization before you begin working, and even if you try to have some initial organization as you start writing you will find missing details and then have to fit them in.
- andrei_says_ 4y ago
  One way is to just dump all the info like a reference. Another would be to write some of the stories describing the scenarios that forced you to learn this. Take a look at Julia Evans’ writing for inspiration. https://jvns.ca/ https://jvns.ca/
- andrei_says_ 4y ago
  One way is to just dump all the info like a reference. Another would be to write some of the stories describing the scenarios that forced you to learn this. Take a look at Julia Evans’ writing for inspiration. https://jvns.ca/ https://jvns.ca/ Also, https://rachelbythebay.com/w/ https://rachelbythebay.com/w/ Providing the real life scenario makes the reference memorable - the human brain is set to remember things that matter and discard things that don’t. A story establishes the usefulness of the things.

Damogran6 4y ago

it's all so ad-hoc and random. Firewalls have expensive and cheap operations...passing a packet? Cheap. Opening the packet and rewriting the header? Expensive. That can be leveraged for evil. How do you even organize that kind of random trivia?

Alekhine 4y ago
I don't know much about firewalls. I wasn't aware they could alter traffic, for example. What do you mean it can be leveraged for evil? As for organization, I just dump everything I learn in a markdown file on that topic, then look for structure later. So I would just open a file, call it `firewalls.md` and write that down in there. You can accrete a lot of written knowledge over time this way.
- ilc 4y ago
  They can be used for all types of stuff. Imagine two companies merging. They both used 10.100.0.0/16. If you were in one of the companies wouldn't it be nice if the other re-ip'd? ... Guess what.. they won't and you don't want to. So you make a box, that turns your ips into 10.101.0.0/16 and theirs into 10.102.0.0/16... and you leave your IPs alone :). Yeah, some things won't work across that bridge. But it'll get you started. Firewalls can do really, really evil stuff. DNS? Yeah, we'll answer ALL dns queries.. Even ones you send to 8.8.8.8, or 1.1.1.1... The BOFH playbook is large, and varied. :)
- Damogran6 4y ago
  Networking, not just firewalls, is about looking at a packet, opening it up, and either passing it along to the next link in the chain, or making a change to (typically) the header and sending it along. There's a TTL or Time To Live value to make packets eventually die, otherwise, packets could potentially move from router to router forever. So at a minimum, your firewall, or router, rewrites the header to Decrement the TTL by one with every hop. Which spawns a really interesting thought experiment that results in the creation of the traceroute utility.
Jtsummers 4y ago
> How do you even organize that kind of random trivia? Having been slowed down in the past by this kind of thinking: My advice is don't. You throw the information together and forget about organization (as in a final presentable organization), you just write. Use systems like tags (metadata) to attach concepts and use queries on the tags to find related things. As you build up the knowledge base you can start organizing it more properly, into real essays or chapters and sections. Not all knowledge is amenable to pre-organization before you begin working, and even if you try to have some initial organization as you start writing you will find missing details and then have to fit them in.
andrei_says_ 4y ago
One way is to just dump all the info like a reference. Another would be to write some of the stories describing the scenarios that forced you to learn this. Take a look at Julia Evans’ writing for inspiration. https://jvns.ca/ https://jvns.ca/
andrei_says_ 4y ago
One way is to just dump all the info like a reference. Another would be to write some of the stories describing the scenarios that forced you to learn this. Take a look at Julia Evans’ writing for inspiration. https://jvns.ca/ https://jvns.ca/ Also, https://rachelbythebay.com/w/ https://rachelbythebay.com/w/ Providing the real life scenario makes the reference memorable - the human brain is set to remember things that matter and discard things that don’t. A story establishes the usefulness of the things.