Guest VM Migrated from hyper-v: network not working

[OhmegaStar]

Hi,
I'm migrating from HyperV to Proxmox VE 9, I've made the needed setup and have two bridges configured. i can reach the management interface fine on the ip's set on the bridges.


my first migration is proxmox pmg, the vm starts fine, i can log in on the console. but it is unreachable from the rest of the network, and has no internet.

network/interfaces;


I've created a test VM installation of a ubuntu desktop utilizing my bridge, and this works as expected, theres internet access.
from the ubuntu desktop:




the bridge used (vmbr1):



I've tried setting the nic for the pmg VM to VirtIO and IntelE1000, it makes no difference.
I assume i'm missing something basic in connection with the fact that the vm is migrated from Hyper-V, but I have not found the cause.

Any Suggestions?

/OhmegaStar

 

[Neobin]

my first migration is proxmox pmg, the vm starts fine, i can log in on the console. but it is unreachable from the rest of the network, and has no internet.
View attachment 90015
network/interfaces;
View attachment 90016

In: /etc/network/interfaces change both occurrences of: eth0 to: ens18 and reboot the VM.

the bridge used (vmbr1):
View attachment 90020

Sidenote 1:
Generally, it is not recommended to have multiple interfaces on the same system in the same subnet...

Sidenote 2:
Are those multiple physical interfaces per vmbr intentional or do you maybe want bonding?:

B

Post in thread 'Why can I add two network devices to a bridge?'

Dec 15, 2022

Hello,

a bridge is something like a switch. If you add two NICs to a bridge, you can make two different connected network devices talk to eachother via the bridge.

A bond combines several NICs to for one big 'virtual' network device. Depending on how the bond is set up that can increase the bandwidth and/or add redundancy.

If you are not bonding your interfaces do NOT add several interfaces to one nic and connect them to the same switch, as this will cause a network loop.

The IP on the bridge is an IP address that your Proxmox host holds. So through this IP you can connect to your...

• B.Otto

https://pve.proxmox.com/pve-docs/chapter-sysadmin.html#sysadmin_network_bond

 

[OhmegaStar]

@Neobin Thanks, that solved the issue (changing the interface name to ens18) now i have connectivity.
re the other questions of multiple physical per bridge, that is only temporary, as the server is connected to two different switches, and theres a short path to the vm's being imported on each, so once i have migrated i will create a more normal network config. (and probably do some bonding and LACP for the management bridge), the fibre bridge will suffice on a single 10gb fc.

Thanks a lot for the quick help, may I ask a followup question, how did you arrive at ens18 being the right interfacename ?

/OhmegaStar

 

[OhmegaStar]

Oh I See, the working VM references ens18

 

[Neobin]

[...] how did you arrive at ens18 being the right interfacename ?

The ip a output of the VM in question. (Your very first screenshot.)