Thank you a lot. All this is very concise and clear. I have to digest it first and try to translate it into programming code. All I need to do, and that is why I posted this here, is to replace a serial point-to-point RS232 connection by a UDP/IP connection, that sends one Byte every 100ms in both directions.
If you don't mind I will get back to you. Friendly Chris -----Ursprüngliche Nachricht----- Von: wkitt...@windstream.net [mailto:wkitt...@windstream.net] Gesendet: Sonntag, 18. Dezember 2016 21:16 An: synalist-public@lists.sourceforge.net Betreff: Re: [Synalist] filtering of UDP port numbers On 12/18/2016 02:51 PM, S.C.T.N Gmbh wrote: > Thank you, > > Quote: <<the local port and the remote port are two different things>> > I am really getting confused. yes, it can be confusing... especially when documentation is written from a different standpoint than the sender or the receiver POV... > HostA is listening on 18002 and can still receive through 18001? no... if hostA is to receive on 18001, it must listen on 18001... so, let's take a scenario: 1. hostB needs to send data to hostA. 2. hostA is listening on it's local port 18002. 3. hostB uses any local source port to connect to hostA's remote destination port 18002. looking at this from a man in the middle position: 1. hostB selects some port to send on. MITM sees this as the "source port". 2. hostB is sending the data to hostA on port 18002. MITM sees this as the "destination port". looking at this from hostA position: 1. i'm listening on port 18002. 2. my port 18002 is the "destination port" all remotes have to send to. 3. i see the port that the remotes use to send from as the "source port". looking at this from hostB position: 1. i need to send data to hostA. 2. hostA is listening on "destination port" 18002. 3. i will select some random port as my "source port" to connect to hostA's port 18002. does that help? -- NOTE: No off-list assistance is given without prior approval. *Please keep mailing list traffic on the list* unless private contact is specifically requested and granted. ---------------------------------------------------------------------------- -- Check out the vibrant tech community on one of the world's most engaging tech sites, SlashDot.org! http://sdm.link/slashdot _______________________________________________ synalist-public mailing list synalist-public@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/synalist-public ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, SlashDot.org! http://sdm.link/slashdot _______________________________________________ synalist-public mailing list synalist-public@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/synalist-public
