Solved: weid scenario of same udp source ports on hosts

sarahr202 · ‎01-30-2009

Hi every body!

I have this fictious scenario.

There are two hosts h1 and h2 and a server on a same subnet

application 1 = udp port 45

application 2= udp port 46

server running these two applications

h1 using udp port 50 for appli 1.

h2bbusing udp port 50 for appli 2.

both h1 and h2 don't have ip address, so h1 send the broadcast with for appli 1, h2 sends the boadcast for appli 2.

Server receives the broadcast from h1 for appli 1 and then from h2 for appli 2..It sends the response back at broadcast address from appli 1. i.e dest udp 50 src udp 45. Since it was broadcast both h1 and h2 receives it. h1 will processes it. H2 was waiting for the response from appli 2. So when h2 receives braodcast from appli , how would h2 determine that broadcast is not meant for him , as dest udp port is same i.e 50 but the src udp port is 45 not 46.Will h2 determine that broadcast is not meant for him by looking at src udp port 45.?

thanks a lot!

Yudong Wu · ‎01-30-2009

You need check with vendor of that application.

From network side, H2 will process the packet and send it to the application who are listening to UDP port 50. Then the decision (drop it or not) will be made in your application.

View solution in original post

Yudong Wu · ‎01-30-2009

You need check with vendor of that application.

From network side, H2 will process the packet and send it to the application who are listening to UDP port 50. Then the decision (drop it or not) will be made in your application.