Please add support for the counter type (ASN_COUNTER, type 0x41) in the snmpset utility.
Per section 7.1.6 of RFC 2578 (SMIv2), counters are read-only. :
The value of the MAX-ACCESS clause for objects with a SYNTAX clause
value of Counter32 is either "read-only" or "accessible-for-notify".
The SMIv1 definition of "counter" does not have that restriction. Since snmpset supports SNMPv1, and since SNMPv1 uses SMIv1, I think it makes sense to fully support to the SMIv1types.
snmp SETs to counters are not legal, according to the SMI and SNMP protocol definitions. Do you have a MIB that actually is allowing it?
Moving to feature requests, since it's arguable that SMIv1 doesn't prohibit it. Maybe someone will supply a patch??