[Bug Report] Invalid CIDR addres error when setting LAN as network address

[justuswilhelm]

Describe the bug:

Include the following information:

• OpenSnitch version: 1.7.2
• OS: NixOS
• OS version: 25.11 (Xantusia)
• Window Manager: sway version 1.11
• Kernel version: Linux helium 6.12.73 #1-NixOS SMP PREEMPT_DYNAMIC Mon Feb 16 16:09:13 UTC 2026 x86_64 GNU/Linux

To Reproduce:

Steps to reproduce the behavior:

1. Open OpenSnitch Network Statistics
2. Press Create a new rule...
3. Enter LAN-invalid-CIDR in Name field
4. Select Network tab
5. Check To this IP / Network
6. Select LAN from the drop down to the right of the To this IP / Network field
7. See the following error appear below:

Error applying rule: (2) error compiling rule: CIDR parsing error: invalid CIDR address: LAN

Post error logs:

From journalctl -f -u opensnitchd.service:

Mar 06 10:54:25 XXX opensnitchd[87218]: [2026-03-06 01:54:25] WAR Operator.Compile() error: CIDR parsing error: invalid CIDR address: LAN: LAN
Mar 06 10:54:25 XXX opensnitchd[87218]: [2026-03-06 01:54:25] WAR [notification] Error changing rule: (2) error compiling rule: CIDR parsing error: invalid CIDR address: LAN [Enabled] LAN-invalid-CIDR: if(dest.network is 'LAN'){ deny once }

Expected behavior (optional):

OpenSnitch should let me use the LAN network for filtering.

Screenshots:

Additional context:

I've tried setting it directly as a JSON rule. In that case, the To this IP / Network field shows 169.254.0.0/16 when setting the value to LAN in JSON.

[gustavo-iniguez-goya]

hi @justuswilhelm !

Verify that the files /etc/opensnitchd/network_aliases.json and /usr/lib/python3.13/site-packages/opensnitch/utils/network_aliases/network_aliases.json (use the path to your python installation) exist.

Both are available here:

https://github.com/evilsocket/opensnitch/blob/master/daemon/data/network_aliases.json
https://github.com/evilsocket/opensnitch/blob/master/ui/opensnitch/utils/network_aliases/network_aliases.json

[gustavo-iniguez-goya]

Issue reproduced. The reason is that the file /etc/opensnitchd/network_aliases.json is missing.
Copy it to /etc/opensnitchd/network_aliases.json as mentioned above and it should work.

Thanks!