Sending a broadcast UDP snmp message to a device running snmpd 184.108.40.206 will fail:
$ snmpget -v 2c -c public 255.255.255.255 iso.org.dod.internet.mgmt.mib-2.system.sysObjectID.0
$ tail -f snmpd.log
Turning on AgentX master support.
NET-SNMP version 220.127.116.11
send response: Failure in sendto
I did a git bisect and narrowed it down to this commit:
09ee3c4 2006-09-14 22:13:07 +0000 Wes Hardaker: NEWS: snmplib: PATCH: 1553447: responses will get sent from the original dest IP address
The feature worked until then. It does not seem to me that this was on purpose. Has this been fixed in a newer version?