I am sending snmpv3 traps out using app 'snmptrap' and not able to see the traps on trap-receiver side (snmptrapd) only for snmpv3-user whose security level is noAuthNoPriv . Below mentioned are my test details.

Details:

system1: ip=172.16.1.214, sends snmpv3 trap to 'system2' using 'snmptrap

system2: ip=172.16.1.131, has 'snmptrapd' running and receives trap messages and logs it

System1: sending two SNMPv3 trap out

# snmptrap -v 3 -n "" -l noAuthNoPriv -u trapuser1 -e 0x0123456789010384 172.16.1.131 69 .1.3.6.1.4.1.8072.2.3.1 .1.3.6.1.4.1.8072.2.1.1 i 13

# snmptrap -v 3 -n "" -a SHA -A mypassword -l authNoPriv -u trapuser2 -e 0x0123456789010384 localhost 69 .1.3.6.1.4.1.8072.2.3.1 .1.3.6.1.4.1.8072.2.1.1 i 14

System2: Trap-receiver

~$cat /etc/snmp/snmptrapd.conf

createUser -e 0x0123456789010384 trapuser1
createUser -e 0x0123456789010384 trapuser2 SHA mypassword
authUser log trapuser1
authUser log trapuser2

~$snmptrapd -c /etc/snmp/snmptrapd.conf

NET-SNMP version 5.4.3 NET-SNMP version 5.4.3

usm: usm: USM processing begun...
USM processing begun...
usm: usm: match on user trapuser1 <---- (comment) trapuser1 has noauth no encrypt (/comment)
match on user trapuser1
usm: usm: USM processing completed.
USM processing completed. < --- (comment) received trap not got logged (/comment)

Question: why snmptrapd not able to log the received trap for snmpv3 user(trapuser1) which has noAuthNoPriv, though config file has 'authUser log trapuser1'?

usm: usm: USM processing begun...
USM processing begun...
usm: usm: match on user trapuser2 <---(comment)trapuser2 has only auth (/comment)
match on user trapuser2
usm: usm: Verification succeeded.
Verification succeeded.
usm: usm: USM processing completed.
USM processing completed.
2014-12-10 21:41:07 localhost [UDP: [127.0.0.1]:36661->[127.0.0.1]]: iso.3.6.1.2.1.1.3.0 = Timeticks: (69) 0:00:00.69 iso.3.6.1.6.3.1.1.4.1.0 = OID: iso.3.6.1.4.1.8072.2.3.1 iso.3.6.1.4.1.8072.2.1.1 = INTEGER: 14
2014-12-10 21:41:07 localhost [UDP: [127.0.0.1]:36661->[127.0.0.1]]: iso.3.6.1.2.1.1.3.0 = Timeticks: (69) 0:00:00.69 iso.3.6.1.6.3.1.1.4.1.0 = OID: iso.3.6.1.4.1.8072.2.3.1 iso.3.6.1.4.1.8072.2.1.1 = INTEGER: 14 <-- (comment) received trap got logged (/comment)