Re: [lwip-users] how lwip know internet cable is unplug

[Simon Goldschmidt]

Kieran Mansley <address@hidden> wrote:
> An: address@hidden
> Betreff: Re: [lwip-users] how lwip know internet cable is unplug

> On Fri, 2011-09-02 at 05:26 +0000, vincent cui wrote:
> > When unplug internet cable, how lwip deal it ?
> 
> It doesn't.  Whether the link is up or not is of no real interest to a
> TCP/IP stack.  It will just try to send packets, and the lower layers
> (e.g. the driver you're using) have to deal with the link status.

That's only half the truth. At least dhcp/AutoIP use this information: they 
restart address negotiation after the link status has been changed to 'up' 
(using netif_set_link_up()). After all, this is a feature which should be 
implemented when using dhcp/AutoIP or the lwIP device will continue to use an 
address of one subnet when plugged into another subnet until the original lease 
would expire.

Simon
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