Can someone try explaining (in simple terms) how Wi-Fi routers push nameservers and routes to my resolv.conf? I've noticed it gets changed automatically as I move between different Wi-Fi networks. I think it's related to dnsmasq and/or DHCP, but the technical details I'm finding via Google searches are a little complex for my level of understanding (i.e., my brain is too small).

And how hypothetically/theoretically this can be used/manipulated by hackers on a public/shared Wi-Fi network?

    > lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 16.04.4 LTS
Release:    16.04
Codename:   xenial
  • 4
    These are two questions: 1. how does it work in the first place and 2. can this be used for attacks. The first question is off-topic and the answer to the seconds is DHCP spoofing, which you probably understand only once you understand how this works in the first place - therefore marked as off-topic. Also "the technical details I'm finding via Google searches are a little complex for my level of understanding" says nothing about what you've found and what you are able to understand and thus is of no help in creating an answer you are able to understand - therefore downvoted. – Steffen Ullrich Mar 21 '18 at 10:54

Wifi routers are not pushing anything to your resolv.conf file. If your IP address is changing, then your host (presumably a laptop) is using DHCP in which case it is not using resolv.conf. IP addresses provisioned using DHCP are constantly changing and you "lease" them and the lease expires after a period of time. If you setup a host to resolve DNS by using resolv.conf, the DNS will never change and once it is set, depending on what it is set to, the DNS might not work on some networks if you have a host (like a laptop) that you are moving around from place to place and network to network.

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