# Re: \[PATCH 1/1\] tun: change speed from 10M to dynamically configured

- From: Fan Du \<hidden\>
- Date: 2015-02-13 03:30:23 
- List: netdev
- Page: https://ratatoskr.run/netdev/2015/02/10978014
- Thread: https://ratatoskr.run/netdev/2015/02/10977977/t.md

```text
于 2015年02月13日 10:45, yzhu1 写道:
> On 02/12/2015 08:55 PM, Stephen Hemminger wrote:
>> On Thu, 12 Feb 2015 13:35:23 +0800
>> Zhu Yanjun [ref] wrote:
>>
>>> From: Zhu Yanjun <redacted>
>>>
>>> The default speed of normal nic is 1000M while the default speed
>>> of tun is 10M. Now the default speed of tun is changed to 1000M.
>>> And there are 3 options: 10M, 100M and 1000M to the speed of tun.
>>> The command "ethtool -s tun0 speed 10/100/1000" can configure the
>>> speed of tun dynamically.
>>>
>>> CC: Michael S. Tsirkin <mst@redhat.com>
>>> CC: Jason Wang <redacted>
>>> CC: Al Viro <viro@zeniv.linux.org.uk>
>>> Signed-off-by: Zhu Yanjun <redacted>
>>> Signed-off-by: Zhu Yanjun <redacted>
>> Why limit to 10/100/1000 speed?
>> Ethtool speed can be any value
> Thanks for your comments.
>
> Yes. But the real physical nic speed often 10M, 100M and 1000M.
> This simulates the physical nic.
   ^^^^^^^^^^^^^^^
then a speed control logical would be needed to effect the corresponding speed
when tun/tap gets/puts packets corresponding to the speed setting.

What's the benefit when changing speed from 10Mb/s to 1000Mb/s?

Just xia bibi ;)
```