Using version 1:
% snmpget -c COMMSTRING -M /usr/local/share/snmp/mibs -v 1 -m
USAGE-MIB:PROXY-MIB:REDLINE-STATS-MIB:REDLINE-STATS-MIB:REDLINE-CONFIG-M
IB hostname REDLINE-STATS-MIB::sessActive.0 Error in packet
Reason: (noSuchName) There is no such variable name in this MIB.
Failed object: REDLINE-STATS-MIB::sessActive.0
Using version 2 (2c):
% snmpget -c COMMSTRING -M /usr/local/share/snmp/mibs -v 2c -m
USAGE-MIB:PROXY-MIB:REDLINE-STATS-MIB:REDLINE-STATS-MIB:REDLINE-CONFIG-M
IB hostname REDLINE-STATS-MIB::sessActive.0
REDLINE-STATS-MIB::sessActive.0 = Counter64: 12247
Slightly annoying that – but makes certain sense