Ip fragmentation and reassembly with winpkfilter

[weihao.ma]

Hi, i want to archieve the udp-tunnel between client and server, and i don’t want to use mtu-decrement(because of changing this value needs computer reboot), so i set the mtu-decremnt to 0, and i do the following things:

From the client, i ping the server with a command of “ping 192.168.1.250 -l 1628 -t”, the winpfilter capture the first packet to the server with the IP_MP flag and 1500 ip length. if i want to wrapper the first packet to my udp header to archieve the udp-tunnel, the packet size must be larger than the max-frame-size(1514), and Is possible i fragment the ip packet?

If i fragment the ip packet in my client, what to do with the server application?

[Vadim Smirnov]

Yes, you can fragment the resulted packet and send out two packets instead one, server will reassemble it. However, please note that fragmented packets often are blocked by firewalls.

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