I found logs in 1.4:
Jan 5 13:59:31 r11-roll zebra[1007]: [TBZ37-E2AXD][EC 100663310] snmp[err]: Cannot find module (IANAifType-MIB): At line 13 in /usr/share/snmp/mibs/IF-MIB.txt Jan 5 13:59:31 r11-roll zebra[1007]: [RZ3YY-GPH41][EC 100663310] snmp[warning]: Did not find 'IANAifType' in module #-1 (/usr/share/snmp/mibs/IF-MIB.txt) Jan 5 13:59:31 r11-roll zebra[1007]: [TBZ37-E2AXD][EC 100663310] snmp[err]: Cannot find module (IANA-RTPROTO-MIB): At line 12 in /usr/share/snmp/mibs/IP-FORWARD-MIB.txt Jan 5 13:59:31 r11-roll zebra[1007]: [RZ3YY-GPH41][EC 100663310] snmp[warning]: Did not find 'IANAipRouteProtocol' in module #-1 (/usr/share/snmp/mibs/IP-FORWARD-MIB.txt) Jan 5 13:59:31 r11-roll zebra[1007]: [QN9FK-3DQX7] snmp[info]: NET-SNMP version 5.9 AgentX subagent connected Jan 5 13:59:31 r11-roll ripd[1030]: [TBZ37-E2AXD][EC 100663310] snmp[err]: MIB search path: $HOME/.snmp/mibs:/usr/share/snmp/mibs:/usr/share/snmp/mibs/iana:/usr/share/snmp/mibs/ietf
Not sure if it is used anywhere else, but they don't exist in 1.4
vyos@r11-roll:~$ sudo ls -la /usr/share/snmp/mibs/ | grep -i IANA vyos@r11-roll:~$
They were in 1.3:
vyos@r4:~$ sudo ls -la /usr/share/snmp/mibs/ | grep -i IANA -rw-r--r-- 1 root root 6845 Dec 8 2014 IANA-ADDRESS-FAMILY-NUMBERS-MIB.txt -rw-r--r-- 1 root root 32837 Dec 8 2014 IANAifType-MIB.txt -rw-r--r-- 1 root root 4389 Dec 8 2014 IANA-LANGUAGE-MIB.txt -rw-r--r-- 1 root root 3803 Dec 8 2014 IANA-RTPROTO-MIB.txt vyos@r4:~$