Wrong network speed congif for tap NIC

[Eduard Reñé Claramunt]

I installed the Proxmox 5.0 in a machine with a NIC that supports 1Gb/s and the virtual machine networks were performing really bad, so I checked with ethtool and I saw an automatically configured network with a speed set to 10Mb, I tried to force change it with 'ethtool -s tap103i0 speed 1000 duplex full' and it says that the operation is not supported.
I tried it with Linux bridge and with Open VSwitch without luck, and also I followed this steps https://www.lowendtalk.com/discussion/25317/fixing-network-speed-in-kvm without any luck either.

How can I change the speed of the tap NIC?


Thank you!

 

[Symbol]

You don't. A tap interface is virtual, and has no speed. The "10Mb/s" reported by ethtool is a default value hardwired in the tap driver, just to report something when asked, but is completely meaningless, as the real speed really is "as fast as possible".
So, your problems come from something else.

 

[Vineet Gupta]

@Symbol , I ran into the same issue , so if you are saying that it's virtual then on the host when this tap interface gets mapped and attached to the qbr bridge it should show the speed of the interface there , so I assume it should show the same as Host , I have my qbr and br-int and br-tun showing all 10Gbps but only this tap interface shows 10Mbps , why is it so ??