[Winpcap-users] winpcap and ip change

Thorsten Stoffregen thorsten.stoffregen at gmx.de
Wed Sep 22 05:12:41 PDT 2010


I am building an application which listen to Level 2 Realtime Traffic.
My problem is, that the overlying application has to change the 
ip address of the interface on which I am listening with pcap.

After changing the ip I there are packets missing 
in the capture. 
Especially pakets with Ethernet.Type = 0x8892 (Profinet),
standard traffic like arp request is still visible.

I can reproduce this problem even with wireshark 
(ip changed with netsh).

One solution I found is to close and reopen the 
device (pcap_close, pcap_open), but only if I wait
long enough between the calls (I wait about 5 seconds
after the ip change, 2 s doesn't work). 
So I can imagine there is something
in the driver only shutting down or restarting if I wait
long enough... Maybe someone has an idea how I can
solve this. Waiting for 5s seems not a good solution...

System is Windows 7, WinPcap 4.1.2


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