Re: [lwip-users] bind with link down

[address@hidden]

Am 03.04.2020 um 12:46 schrieb Massimiliano Cialdi:
> On Fri, Apr 3, 2020 at 1:28 AM Sylvain Rochet <address@hidden> wrote:
>> netif_set_up() and netif_set_down() is a software switch telling the
>> lwIP stack if you want the interface to be active or silent. If you
>> don't need to disable an interface at runtime (with only one interface,
>> you never need that!), you only have to call netif_set_up() once at
>> init.
>>
>> netif_set_link_up() and netif_set_link_down() may be called when cable
>> is plugged or unplugged. Calling netif_set_link_down() then
>> netif_set_link_up() is optional and only meant to speed up DHCP recover,
>> IPv6 discovery, or such. If you don't care about speeding up things on
>> cable connection you only have to call netif_set_link_up() once at init.
> I confess my lack of knowledge on these matters.
> I didn't know that if I have just one interface, I never need to put it down.
> And I wouldn't know after which events to put the interfaces up/down
> in case I had more than one.
> And, if I understand correctly, when the ip is static I don't even
> need to set the link down when cable is unconnected.

No, you should still set the link down if you can detect it. It's not
required, but it might improve *some* things if that is known.

Regards,
Simon

> Where could I find documents or books to increase my know-how on these topics?
>
> best regards
> Max
>