Path: utzoo!utgpu!watserv1!watmath!att!linac!pacific.mps.ohio-state.edu!zaphod.mps.ohio-state.edu!sdd.hp.com!hplabs!hpfcso!hpcndaw!rpc
From: rpc@hpcndaw.CND.HP.COM (Ron Poppen-Chambers)
Newsgroups: comp.protocols.tcp-ip
Subject: Re: SNMP UDP port
Message-ID: <810020@hpcndaw.CND.HP.COM>
Date: 29 Apr 91 16:58:40 GMT
References: <1991Apr24.182452.7403@bigsur.uucp>
Organization: HP Colorado Networks Division
Lines: 39

> 
>   In the RFC 1157 section 4 "Protocol Specification", it
> states "A protocol entity receives messages at UDP port
> 161 on the host ....".
> 
> Here are the questions:
> 
> (1) Does the statement implies that a Network management
>     station must receive SNMP message (other than traps)
>     on UDP port 161?
>    (1.1) If (1) is yes, then NMS and the agent cannot
>          both reside on the hosts (e.g.workstation)?
> 

No to (1). The management station should only receive traps and responses
to requests. This can be done on a port other than 161.

> (2) Is it a protocol violation to receive messages on any
>     other UDP ports (other than traps on 162)?

I believe that an object manager/agent would be in violation if it did this.


> (3) In practice, could we assign any unreserved port to
>     the source port of the outgoing get_request message
>     (with destination port 161)?  Should we expect to receive
>     a get_response on the same port that we assigned to
>     the outgoing get_request? In this case is the statement
>     quoted from RFC 1157 violated?

I believe this is the prefered method. The response should be sent to the
port that sent the request, but I don't believe that this is explictly 
stated in the RFC.


-----------------

Ron Poppen-Chambers
rpc@hpcnd.cnd.hp.com