Was noticing these errors recurring every 30 seconds in the /var/log/system.log.
2007:11:12-14:55:25 (none) snmpd[15921]: error getting netmask for interface 3
2007:11:12-14:55:55 (none) snmpd[15921]: error getting netmask for interface 3
2007:11:12-14:56:25 (none) snmpd[15921]: error getting netmask for interface 3
2007:11:12-14:56:55 (none) snmpd[15921]: error getting netmask for interface 3
2007:11:12-14:57:25 (none) snmpd[15921]: error getting netmask for interface 3
2007:11:12-14:57:55 (none) snmpd[15921]: error getting netmask for interface 3
2007:11:12-14:58:25 (none) snmpd[15921]: error getting netmask for interface 3
2007:11:12-14:58:55 (none) snmpd[15921]: error getting netmask for interface 3
2007:11:12-14:59:25 (none) snmpd[15921]: error getting netmask for interface 3
2007:11:12-14:59:55 (none) snmpd[15921]: error getting netmask for interface 3
I did a kill -HUP on the PID for snmpd, wondering if it would fix it.
After restarting, I saw these entries:
2007:11:12-15:02:58 (none) snmpd[15921]: Reconfiguring daemon
2007:11:12-15:02:58 (none) snmpd[15921]: NET-SNMP version 5.3.0.1 restarted
2007:11:12-15:02:59 (none) snmpd[15921]: error finding row index in _ifXTable_container_row_restore
2007:11:12-15:03:25 (none) snmpd[15921]: error getting netmask for interface 3
2007:11:12-15:03:55 (none) snmpd[15921]: error getting netmask for interface 3
2007:11:12-15:04:25 (none) snmpd[15921]: error getting netmask for interface 3