Disable generic receive offload

[dain-bramage]

I am running Ubuntu 20.04

I have a separate NIC I use for Wireshark captures. The NIC is performing generic receive offload. This means I am not actually capturing the packets as they appear on the wire.

I can manually turn this off with

ethtool -K enp4s0 gro off

but this wont survive a reboot.

Can anyone tell me the correct syntax for an entry into /etc/netplan/01-network-manager-all.yaml that would disable GRO automatically for this NIC on boot?

[TheFu]

I've never seen a post-up command in netplan like we had with the interfaces file. If you can't find that capability in the netplan documentation (netplan.io), then the best way I know would be to create a new systemd unit file to do it that has a strong dependency on networking being up. There are a number of different network unit files, so you'll need to look up which is actually the one that brings up interfaces.

BTW, you'll need to put the full path to ethtool into the command. Don't expect there to be any PATH set that early in boot.