On 24 February 2010 23:25, Fatima Peter <[email protected]> wrote: > I think I spoke too soon without testing with other snmptools. The > snmpd (from net-snmp) as well as our proprietary "trapd" gets the > response for INFORM from the other hand only if the remote end uses > the source-port of 162 like snmptrapd does. > > We tried with other snmptools ("Unbrowse Snmp" for example) which only > guarantees that the udp dest port is the same as the udp orig port in > the INFORM request. The products use ports like 1048 as udp source > port and even snmpd does not get the response to INFORM messages > coming from the other end. > > Would like to know whether this is the expected behavior and whether > you have any suggestions for the issue.
I'm not sure I fully understand what you are saying here. I haven't checked the specs closely, but I believe the general expectation of UDP-based service in general (not just SNMP), is that given a request sent from source (1.2.3.4 port A) to (6.7.8.9 port B), then the response will be sent from (6.7.8.9 port B) to (1.2.3.4 port A). This allows the original application to match up responses with the corresponding initial request. I *think* what you're saying is that a request: ( 1.2.3.4 : A ) -> ( 6.7.8.9 : B ) may result in a response ( 6.7.8.9 : C ) -> ( 1.2.3.4 : A ) ? I couldn't quote chapter and verse, but my immediate reaction is that this is not valid. If nothing else, how can such an approach handle two recipient applications on the same destination host? Given ( 1.2.3.4 : A ) -> ( 6.7.8.9 : B ) "Have I won the lottery?" ( 1.2.3.4 : A ) -> ( 6.7.8.9 : X ) "Am I going to die?" then responses of ( 6.7.8.9 : B ) -> ( 1.2.3.4 : A ) "Yes" ( 6.7.8.9 : X ) -> ( 1.2.3.4 : A ) "No" could be interpreted correctly, while ( 6.7.8.9 : C ) -> ( 1.2.3.4 : A ) "Yes" ( 6.7.8.9 : D ) -> ( 1.2.3.4 : A ) "No" would leave me in a state of considerable uncertainty! A single UDP-based transaction really must use a consistent source/destination addressing quad (i.e. IP addresses and UDP ports), in order to identify the transaction that it refers to. But I don't know if that's what you mean here. Dave ------------------------------------------------------------------------------ Download Intel® Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev _______________________________________________ Net-snmp-coders mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/net-snmp-coders
