SNMP (Simple Network Management Protocol) is an Internet protocol dedicated for the management of devices on networks. Typically, routers, switches, servers, workstations, printers, modems and many other devices support SNMP. SNMP is mostly utilized in NMS (Network Management Systems) for monitoring various conditions on devices that need the network administrator’s attention. SNMP is defined by IETF (Internet Engineering Task Force) as a part of IPS (Internet Protocol Suite). SNMP is a combination of network management standards such as a protocol for application layer, schema for databases and a data objects collection. SNMP describes the configuration of the system by exposing variables (management data) on the managed systems. Therefore, other managing applications can query these variables for monitoring purposes, and can occasionally set these values. SNMP v1 and SNMP v2 are the two previous versions of the SNMP protocol (SNMP v3 is the current version).
What is SNMP v1?
SNMP v1 (also known as SNMPv1 or SNMP version 1) is the initial version of SNMP protocol. SNMP v1 is defined in RFC 1065 to 1067 and 1155 to 1157. It was developed by a small group of collaborators at a time when the Internet standards and security was not paid much attention. SNMP v1 operates over UDP (User Datagram Protocol), IP (Internet Protocol), CLNS (OSI Connectionless Network Service), DDP (AppleTalk Datagram-Delivery Protocol) and IPX (Novell Internet Packet Exchange). SNMP v1 uses the authentication mechanism of transmitting a “community string” (i.e. a password) in clear text, which is very insecure.
What is SNMP v2?
SNMP v2 (also known as SNMPv2 or SNMP version 2) is defined in RFC 1441 to RFC 1452. SNMP v2 adds several improvements over SNMP version 1. They are improvements in performance along with advancements in security and confidentiality. It also adds improvements in the area of manager to manager communication. GetBulkRequest has been added to retrieve large data amounts by a single request. Earlier, you had to use GetNextRequest iteratively in order to get a bulk of data. However, many users believed that the party based security system in SNMP v2 is too complex for their liking. This was the reason why it did not become popular.
SNMP v2c is the Community-Based Simple Network Management Protocol version 2. It is defined in RFC 1901 to RFC 1908. Actually, SNMP v1.5 was the initial name given to this protocol. Main difference between SNMP v2 and SNMP v2c is the security model. SNMP v2c uses a simpler community based security model (found in SNMP v1). Apart from this difference in the used security model, SNMP v2c can be considered almost similar to SNMP v2. In fact, SNMP v2c is now regarded as the de facto SNMP v2. But, SNMP v2c is still a “Draft Standard”.
What is the difference between SNMP v1 and SNMP v2?
SNMP v2 is the successor to SNMP v1. SNMP v2 have different message formats (differences in header and PDU formats) and protocol operations (two extra operations) compared to SNMP v1. SNMP v2 introduced the GetBulkRequest for retrieving a bulk of data at once. Both SNMP v1 and SNMP v2 are now considered obsolete. But, all SNMP implementations still support both SNMP v1 and SNMP v2.