this post was submitted on 06 Jul 2024
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[–] cerement 48 points 4 months ago (1 children)

really start to worry when it’s 169.254.0.x

[–] joyjoy@lemm.ee 10 points 4 months ago* (last edited 4 months ago) (2 children)

That just means the ~~DNS~~DHCP is disabled.

Edit: words

[–] OsaErisXero@kbin.run 23 points 4 months ago (2 children)

That is not what that means, it means there's no dhcp on that network segment.

[–] joyjoy@lemm.ee 17 points 4 months ago (2 children)

In my defense, whenever there's a networking issue, it's always DNS related.

[–] 4am@lemm.ee 44 points 4 months ago (1 children)

The three stages of grief:

  1. It can’t be DNS
  2. There’s no way it could be DNS
  3. It was DNS
[–] OsaErisXero@kbin.run 4 points 4 months ago (1 children)

DNS being down is why the DHCP server didn't start ;)

[–] prex@aussie.zone 2 points 4 months ago

I can totally see dnsmasq causing this sort of thing.

[–] Neato@ttrpg.network 1 points 4 months ago (1 children)

If there isn't DHCP and you device isn't set for a static IP, would it even connect?

[–] OsaErisXero@kbin.run 1 points 4 months ago

So, no... but also yes.

You're correct that it's unlikely that the device connecting to the network would be able to reach the outside Internet, but it would still be able to reach any local resource to itself, which is to say any other device which is in its network segment and also in the same state (DHCPless) that it is, via what's referred to as a link-local address. These are in the 169.254.x.x/16 or fe80::/10 space and allow devices to self-assign addresses independent of upstream connectivity for communication on the local network segment. Usually, these aren't useful, but these address are consistent, and can be used to directly contact known local hosts from your machine without DHCP. As to whether or not they can reach upstream hosts in this state, the answer is 'probably not', but that's not the same as what you said.

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[–] cerement 23 points 4 months ago
  • “The hotel’s free WiFi is really fast”

  • “the DNS is disabled”