iface is not coming back up fully after ifdown

[Milton Miller II]

On  03/31/2017 around 12:25PM in some timezone, Maxim Sloyko wrote:

>I ran into what I think is a bug with networking interface, but I'm
>not sure what exactly is broken.
>
>If you bring the interface down (ifconfig eth1 down) and then try to
>bring it up (ifconfig eth1 up) it does not fully recover. That is, it
>shows up as RUNNING in ifconfig, you can set up ip/netmask/gw and try
>sending packets, but nothing ever shows up at the other end of the
>wire.
>
>If you unplug the ethernet cable and then plug it back in (thus
>resetting the phy, I believe?), the interface starts working again. I
>tried this with Zaius and  EVB (which have different PHYs) and it's
>broken like this on both.
>
>I suspect that as part of IFF_UP flag handling the kernel (drivier?)
>needs to also reconfigure the link with PHY, but it's not doing that.
>I don't know how this works in the kernel though, so I would
>appreciate any pointers to where I should start digging.
>

Is this with a real PHY or an NC-SI channel?

Do you see messages showing the link coming up after ifconfig up?

Be aware that for NC-SI attached, the kernel always enables the
state to running to be able to send and receive MAC frames to
manage the connection, and there is a secondary interface or
interface state that reflects the true link state.

Sorry I don't have the experience or resources to help further.

milton