Make my IPv6 selfhosted service available on IPv4 network. (discuss.tchncs.de)

submitted 2 years ago by smileyhead@discuss.tchncs.de to c/selfhosted@lemmy.world

13 comments fedilink hide all child comments

My ISP provide me with good IPv6 connection with support of opening ports how I like. But IPv4 is behind a CGNAT and makes me unable to host a service on the legacy Internet.

Unfortunetely some of my friends I want to host (Jellyfin and Nextcloud) for does not have modern Internet connection, so I have to put some proxy.

Now I need suggestions of a solution. VPN on some VPS they would need to connection to is one of them, but it should be as simple for them to use as possible.

you are viewing a single comment's thread
view the rest of the comments

[-] i_am_not_a_robot@discuss.tchncs.de 2 points 2 years ago

Be careful with doing this. X-Real-IP and X-Forwarded-For are good for when the client is a trusted proxy, but can be easily faked if you don't whitelist who's allowed to use those headers. Somebody with IPv6 access could send "X-Real-IP: 127.0.0.1" or something and if the server believes it then you'll see 127.0.0.1 in logs and depending on what you're running the user may gain special permissions.

Also be careful with the opposite problem. If your server doesn't trust the proxy, it will show the VPS IP in logs, and if you're running something like fail2ban you'll end up blocking your VPS and then nobody will be able to connect over IPv4.

[-] TCB13@lemmy.world 2 points 2 years ago* (last edited 2 years ago)

Fair enough yeah. :)

The OP can solve that potential security issue with this option: https://nginx.org/en/docs/http/ngx_http_realip_module.html#set_real_ip_from on the local server nginx:

http {
(...)
        real_ip_header    X-Real-IP;
        set_real_ip_from  [2a03::aaaac::1]; # Replace with the VPS IPv6 address.
}

This will make sure only the VPS is allowed to override the real IP.

this post was submitted on 01 Jun 2024

29 points (93.9% liked)

Selfhosted

62284 readers

267 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:

Detailed Rules Post

Be civil.
No spam.
Posts are to be related to self-hosting.
Don't duplicate the full text of your blog or readme if you're providing a link.
Submission headline should match the article title.
No trolling.
Promotion posts require active participation, with an account that is at least 30 days old. F/LOSS without a paywall has exceptions, with requirements. See the rules link for details. Tags [CBH] or [AIP] are required, see the links in Rule 8 for details.
AI-related discussions and AI-involved promotional posts have additional requirements for tagging, as noted in Rule 7 and the AI & Promotional Post Expanded Rules post, and find example disclosures here.

Resources:

selfh.st Newsletter and index of selfhosted software and apps
awesome-selfhosted software
awesome-sysadmin resources
Self-Hosted Podcast from Jupiter Broadcasting

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

Questions? DM the mods!

founded 3 years ago

MODERATORS

curbstickle@anarchist.nexus

curbstickle_lw@lemmy.world