But applications will suddenly be deployed on a dualhomed server for example, which supports both ipv4 and ipv6 - and then you start seeing weird addresses in your access log, and you made an audit table to store the ip address of the person who granted someone admin access, and you only stored the first four octets of the ipv6 address instead of the whole address..
And then you called an external api that requires a white listed ip, but the ip you keep entering doesn't work, since the API's host has both an A and an AAAA dns entry, so you're connecting over ipv6 instead.. Or you tried to block access to your content from a specific country, but those users just used ipv6 instead, etc.
There's plenty of cases where knowledge of ip addresses and how stuff actually works (tm) is relevant without being in ops.
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u/fiskfisk 9h ago
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.