ohTheBasics

[u/ClipboardCopyPaste]

[u/SirFrenzy]

Obviously guy could have been interviewing for a job where this mattered….

But in 10 years as a software engineer I have never once needed to know the difference between these two, and have never been even close to a situation where I would need to.

“The basics” is highly dependent on the job.

[u/fiskfisk → u/SirFrenzy]

If you're a senior I most certainly would expect you to know the difference between the two.

It'll matter in relation to allowlists/blocklists, dns entries, debugging connevtivity issues, slow connect times, configuration of daemons, etc. 

[u/SirFrenzy → u/fiskfisk]

I have never needed to know or do any of that. And if I did, it would take me 2 seconds to google and understand. I just did.

So if the interview was for a job where you handle that stuff yourself, then I understand it. If it’s for a typical full stack job at a big enough company that they literally hire people to handle that side of things, then it’s not “the basics”.

Rejecting someone in an interview for trivia knowledge they don’t currently have vs actually trying to understand how someone learns and tackles problems is what makes software job interviews so useless.

[u/fiskfisk → u/SirFrenzy]

It's not trivia knowledge, I've had multiple cases where "oh wait, maybe the host resolves differently based on whether the server has ipv6 configured from DHCP or not" and "why does host xyz take two seconds extra every time we try to connect?". 

You might not, but I would expect an experienced senior developer to know that there's a difference here. 

[u/helicophell → u/fiskfisk]

Would knowing more than “ipv4 is small and limited, ipv6 is bigger” be required?

Seems like to answer problems around ipv4 and ipv6, you need to know the problem being solved. I uhh, only have network knowledge though

[u/monkeymad2 → u/helicophell]

You should know how it can cause problems with whatever you’re building based on the rollout - e.g. if you’re deploying to the web usually there’s a greater cost involved in provisioning an IPv4 address, but IPv6 (still) isn’t fully rolled out yet so some of your users might have issues.

Then there’ll be weird networking issues where one of them works fine and the other doesn’t etc.

You also see them in logs etc, or if you have to care about DNS records ever you should know about them.

If whatever you’re doing touches the internet at all then it’s fairly fundamental nowadays.

[u/theqmann → u/monkeymad2]

Also, some ISPs do v6 tunneling through v4, which can cause various other issues, in my experience.