Update proxmox-ve.md

config/linux-server/proxmox-ve.md

@@ -16,11 +16,15 @@ Proxmox VE 6
 
 **TODO**
 
-- See [Debian Server: Initial Setup](../debian-server/#initial-setup).
+1. See [Debian Server: Initial Setup](../debian-server/#initial-setup).
   - **TODO**: Differences.
-- Disable the console MOTD:
-  - Disable `pvebanner.service`.
-  - Clear or update `/etc/issue` (e.g. use use the logo).
+1. Disable the console MOTD:
+    - Disable `pvebanner.service`.
+    - Clear or update `/etc/issue` (e.g. use use the logo).
+1. Disable IPv6 SLAAC:
+    - It's enabled on all bridges by default, meaning the node may become accessible to untrusted bridged networks.
+    - In `/etc/sysctl.conf`, set `net.ipv6.conf.default.autoconf=0`.
+    - Reboot (not or later) and make sure there's no unexpected neighbors (`ip -6 n`).
 
 ### Setup SPICE Console