CHR with virito interface not accepting DHCP offer, but e1000 is fine

RouterOS Virtualization
1

Hi all,

I'm running CHR with RouterOS version 6.49.18 in Proxmox (so QEMU/KVM) with the free license to play around and am running into this odd issue: when I configure dhcp-client on my bridge interface bridge1 with a single ethernet slave ether1, a virtio interface configured in Proxmox, the interface/bridge refuses to accept DHCP offers.

When switching the interface type to any of the other available non-paravirtualized options (e1000, e1000e, rtl8913, vmxnet3) bridge happily accepts the DHCP lease.

Additionally, while using virtio, configuring the offered DHCP address statically and sending IP communications using that works fine, so other IP traffic appears to be unaffected. I can also clearly observe the DHCP offer in the packet sniffer log when using virtio.

Is there a special step I am missing for virtio interfaces to correctly handle dhcp-client, or is this a bug?

Thanks,

datdenkikniet

EDIT: Ah, it seems that, whatever the problem was, it's fixed in CHR/RouterOS 7.19.4. I guess that solves it then :slight_smile:

2

virtio driver in linux kernel had a few hiccups back in ancient times of kernel 3.x (used by ROS 6.x). It's got quite a bit better in old times of kernel 5.x (used by ROS 7.x).