Hi,
I have originally a LAN network with 10.0.0.1/23, with DHCP set to 10.0.1.10-10.0.1.250, many devices get a DHCP static IP mapping at 10.0.0.xxx, the rest get a DHCP IP at 10.0.1.xxx.
My VMs in Proxmox all get a static IP mapping starting with 10.0.0.200.
I decided to change all the IPs of my VMs to 10.0.10.xxx. So I changed the LAN interface with 10.0.0.1/16. After that I changed the DHCP static mappings. I also turned off IPv6 and DHCP6.
After a reboot of everything, VMs all get new IP address because they use DHCP.
The VM can connect to anything in LAN except 10.0.0.1. But all VMs have no internet access. All other devices in LAN with 10.0.0.xxx (DHCP static mapping) and 10.0.1.xxx (DHCP) still work perfectly with internet connection.
For example, I have a VM Unifi Controller at 10.0.10.100. I can open the Web UI via 10.0.10.100:8443 using a PC connected in LAN. The UI opens and the controller sees all my switches.
One switch has IP 10.0.0.12. The VM can ping this IP in terminal and get response.
However, when the VM pings 10.0.0.1, there is no response. When the VM pings 8.8.8.8, there is no response. When the VM tries to do apt update, it will fail too because of no internet connection, it doesn’t even resolve the domain name.
Also, a PC connected to LAN can ping my printer in VLAN 10 (10.10.0.12), but my VM cannot
A laptop is connected to VLAN 10 (10.10.0.xxx). I cannot open the Web UI of Unifi controller using this laptop. Ping 10.0.10.100 gives “destination host unreachable”.
I set a DHCP static mapping of 10.0.10.xxx to a PC and plug the wired cable. It also gets an IP address just like the VM, and it also experience the same issue.
I must have missed something very simple but I couldn’t figure it out. Feels like something to do with the firewall rules, but I only have default rules in LAN, which are “allow LAN net to anything” for both IPv4 and IPv6.
Does anybody have an idea what probably has gone wrong?