this post was submitted on 01 Jun 2026
72 points (100.0% liked)

Selfhosted

60526 readers
1349 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

  1. Be civil.

  2. No spam.

  3. Posts are to be related to self-hosting.

  4. Don't duplicate the full text of your blog or readme if you're providing a link.

  5. Submission headline should match the article title.

  6. No trolling.

  7. 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.

  8. 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.

Resources:

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

Questions? DM the mods!

founded 3 years ago
MODERATORS
ruud@lemmy.world
Loki@lemmy.world
CannaVet@lemmy.world
devve@lemmy.world
ayyy@sh.itjust.works
curbstickle@anarchist.nexus
curbstickle_lw@lemmy.world
72
Internal network monitoring (lemmy.world)
submitted 1 month ago* (last edited 1 month ago) by ueiqkkwhuwjw@lemmy.world to c/selfhosted@lemmy.world
21 comments fedilink hide all child comments
 

How do you monitor your homelab network for internal attackers? E.g. you have a publicly available service and theres a vulnerability that you miss or you pull a bad update and suddenly someone has access to your VM/machine/container. How could you increase the chances of automatically detecting that?

The built in IDS in opnsense seems pretty useless, and doesn't really help detect if e.g. someone is trying to exploit services between your vlans (I could be using it wrong though).

Crowdsec in opnsense is nice but it seems to also be primarily for protecting from malicious actors coming from the WAN.

I've heard about the opnsense zenarmor plugin but you have to agree to a privacy policy to use it?

Another option I guess would be collecting firewall logs and making custom notifications for things that you think would be suspicious on your network.

I also know update cooldowns and not exposing anything could largely solve this too, but the monitoring and alerting question really interests me.

you are viewing a single comment's thread
view the rest of the comments
[–] thelittleblackbird@lemmy.world 19 points 1 month ago (1 children)

Segment the network as much as feasible, forbid the communication between the segments via FW rules, and set an alert when those rules are triggered.

For example: your dmz should never initiate any type of communication with your lan segment, your lan segment should not try to access services outside ports 80/443, your dns should log all resolutions performed and it would be nice to have at least a black list.

None of them should have dns over tls, and for specific hosts and networks segments, new domains with very looong active but idle connections should trigger an alert.

My personal opinion is that for a homelab is not realistic to perform a dpi to check that there is not an active attack ongoing, neither from the raw processing power, either from the human effort side, your best chance is to alert when something unusual is happening and then adjust your rules of the are false positives

[–] ueiqkkwhuwjw@lemmy.world 5 points 1 month ago* (last edited 1 month ago) (1 children)

Thanks for your helpful answer.

Do you do all of that on a separate log sever? Or on your firewall? I haven't found a good way to do that on opnsense that doesn't feel hacky.

[–] thelittleblackbird@lemmy.world 5 points 1 month ago

My setup is "simple" and all these monitoring functions are performed in my opnsense box with the telegram plugin.

Most of the alerts are pretty basic and are done into the FW level or the outbound basic logging. So opnsense with the basic tooling is just enough.

I have in my todo to connect the logging system from opnsense to a proper Prometheus/grafana system to really have proper log of several days without having an impact on the FW but I never find the time to do it (lazyness problem)