• Networking & APT
• Firewall(ing) in Proxmox
• NOTES

Networking & APT

1. Networking & DNS issues

I’ve come across a couple issues here about DNS & Networking in Proxmox, but since it’s a Debian machine, the workarounds are pretty simple.

This is a sample /etc/network/interfacesnetworking configuration file (Should be modified and it’s just an example):

auto lo
iface lo inet loopback

# This is the Ethernet interface
iface enp4s0 inet manual

auto vmbr0
iface vmbr0 inet static
        address 10.0.0.4/24
        gateway 10.0.0.1
        bridge-ports enp4s0
        bridge-stp off
        bridge-fd 0


source /etc/network/interfaces.d/*

2. DNS

Change the nameserver at /etc/resolv.conf

3. APT

Sometimes it will use the default proxmox enterprise apt resource list:

In /etc/apt/sources.list.d/ceph.list:

# Just comment the enterprise list and use the no-subscription list:

	#deb https://enterprise.proxmox.com/debian/ceph-quincy bookworm enterprise
deb http://download.proxmox.com/debian/pve bookworm pve-no-subscription

And move the pve-enterprise.list file somewhere else, delete it, etc. (It becomes a redundant apt source and it cause some issues).

Firewall(ing) in Proxmox

Firewall

Proxmox VE Firewall provides an easy way to protect your IT infrastructure. You can setup firewall rules for all hosts inside a cluster, or define rules for virtual machines and containers. Features like firewall macros, security groups, IP sets and aliases help to make that task easier.

pve.proxmox.com

Proxmox VE Full Course: Class 11 - Integrated Firewall

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www.youtube.com

(Somewhat) independent Firewalls:

• All OFF → Open Rules AND THEN turn FW on
• Open rules for the datacenter/proxmox hosts first for ssh/https:8006 (So we can manage everything and avoid locking out)
• VMs have their own dedicated FW; Can have only https:8006 for Proxmox but SSH and https:443 for VM1 and http:80 for VM2

Next steps: Prevent from Pxmx and inside machines to talk (outbound) to other hosts on the network

(Cloudflared): Since I was using Cloudflared to establish an outbound connection, I can deny inbound https traffic without losing the tunnel:

NOTES

• Use Proxmox Darkmode.
• Change sources.list