Hi Noam,
I tried to find out something concerning my problem, but without success. However, I have a little progress. If I call the function dhcp_stop() on link down event (immediately after the call of netif_set_link_down(), then I call dhcp_start() in the same way on link up event, then the DHCP works fine. It works again after the reconnection. But there is still one problem. The callback function for state change is not called when the address is receive. This is a problem for me, because I want to inform the higher level software for the new address and I’m using for this purpose the callback for status change. So actually this is not the solution I want and any further ideas are welcome.
Simeon
From: lwip-users [mailto:address@hidden On Behalf Of Noam Weissman
Sent: Thursday, October 05, 2017 3:20 PM
To: address@hidden
Subject: Re: [lwip-users] FW: Problem with renewing DHCP after link down/up with the new LWIP V2.0.2
Hi Simeon,
I am out of my office till next week so I cannot send any code. I am working with LwIP 2.02
and my DHCP works fine. There were a few small changes in using it.
I suggest searching the forum as this was addressed several times and I am sure you can
find what you need in older correspondence.
BR,
Noam.
From: lwip-users <address@hidden> on behalf of address@hidden <address@hidden>
Sent: Thursday, October 5, 2017 2:50 PM
To: address@hidden
Subject: [lwip-users] FW: Problem with renewing DHCP after link down/up with the new LWIP V2.0.2
I’m still can’t come to a solution of my problem. But my information wasn’t very exact. To be more clear I made a log with Wireshark:
The first 4 lines show normal start-up process. The address is received and all works fine. When the cable is unplugged and plugged again, we see new DHCP request and acknowledge two times (line No. 17 to 23). In this case the state change callback is not called, that means IP address is now received. Then new discover-frame follows.
I need an advice, please!
Simeon
From: address@hidden [mailto:address@hidden]
Sent: Thursday, October 05, 2017 10:15 AM
To: 'address@hidden' <address@hidden>
Subject: Problem with renewing DHCP after link down/up with the new LWIP V2.0.2
Hi,
I’m facing to a problem with the renew of the DHCP after link down/up. With V1.4.1 all worked fine. Probably I’m missing something now. I call correct the functions netif_set_link_up() and netif_set_link_down() when the corresponding events occur. After power on DHCP works fine. But after disconnecting and connecting back the cable, I see that the discover-frame is sent from the stack and an offer-frame is returned from the DHCP server, but there is no reaction from the stack. Also the callback for status change is not called. I tried to call additionally netif_set_up() and dhcp_renew when link up event is generated, but there is no change. Can you give me a hint what I’m missing?
Simeon