this post was submitted on 26 Feb 2024
64 points (93.2% liked)

Selfhosted

40329 readers
401 users here now

A place to share alternatives to popular online services that can be self-hosted without giving up privacy or locking you into a service you don't control.

Rules:

  1. Be civil: we're here to support and learn from one another. Insults won't be tolerated. Flame wars are frowned upon.

  2. No spam posting.

  3. Posts have to be centered around self-hosting. There are other communities for discussing hardware or home computing. If it's not obvious why your post topic revolves around selfhosting, please include details to make it clear.

  4. Don't duplicate the full text of your blog or github here. Just post the link for folks to click.

  5. Submission headline should match the article title (don’t cherry-pick information from the title to fit your agenda).

  6. No trolling.

Resources:

Any issues on the community? Report it using the report flag.

Questions? DM the mods!

founded 1 year ago
MODERATORS
 

Networking noob here. I want to prevent all incoming requests except through a specific port, and that traffic is forwarded to a specific device on the network. NAT seems to do that just fine, it's almost like a kind of firewall by itself. What kind of threats are there that requires more than just NAT for security?

you are viewing a single comment's thread
view the rest of the comments
[–] TheOneCurly@lemm.ee 6 points 9 months ago (1 children)

As I understand it, NAT is a firewall with only a very basic configuration: allow all outbound and accept only established inbound. If you don't expect to have any incoming connections and completely trust all your internal devices then its good enough.

However, if you start wanting to port forward for servers (SSH, FTP, video games) you need to poke holes in the NAT firewall and it has no additional configuration options to help you. The same goes for if you have internal (ex. IoT) devices that you don't necessarily trust, there are no rules to block outbound traffic.

[–] Kid_Thunder@kbin.social 9 points 9 months ago

As I understand it, NAT is a firewall

NAT is not a firewall. NAT does not inspect packet payloads, it doesn't do anything except attempt to route packets to where they are supposed to go. If the connection originates from outside or it is a 'connectionless' protocol, the NAT has no idea which internal IP to route to, so it drops the packet.

NAT provides some security by sheer coincidence and not by design.