Editing Simple Network Management Protocol (section)

=== Version 2 ===
SNMPv2, defined by {{IETF RFC|1441}} and {{IETF RFC|1452}}, revises version 1 and includes improvements in the areas of performance, security and manager-to-manager communications. It introduced ''GetBulkRequest'', an alternative to iterative GetNextRequests for retrieving large amounts of management data in a single request. The new party-based security system introduced in SNMPv2, viewed by many as overly complex, was not widely adopted.<ref name="aethis"/>  This version of SNMP reached the Proposed Standard level of maturity, but was deemed obsolete by later versions.<ref name="rfced">{{cite web|url=http://www.rfc-editor.org/search/rfc_search_detail.php?pubstatus%5b%5d=Standards+Track&std_trk=Any&pub_date_type=any&wg_acronym=snmpv2 |title=RFC Search Detail: Standards Track snmpv2 RFCs|publisher=The RFC Editor |access-date=2014-02-24}}</ref>

''Community-Based Simple Network Management Protocol version 2'', or ''SNMPv2c'', is defined in {{IETF RFC|1901}}–{{IETF RFC|1908}}.  SNMPv2c comprises SNMPv2 ''without'' the controversial new SNMP v2 security model, using instead the simple community-based security scheme of SNMPv1. This version is one of relatively few standards to meet the IETF's Draft Standard maturity level, and was widely considered the ''[[de facto]]'' SNMPv2 standard.<ref name="rfced"/>  It was later restated as part of SNMPv3.<ref>{{IETF RFC|3416}}</ref>

''User-Based Simple Network Management Protocol version 2'', or ''SNMPv2u'', is defined in {{IETF RFC|1909}}–{{IETF RFC|1910}}. This is a compromise that attempts to offer greater security than SNMPv1, but without incurring the high complexity of SNMPv2. A variant of this was commercialized as ''SNMP v2*'', and the mechanism was eventually adopted as one of two security frameworks in SNMP v3.<ref>{{Citation |title=SNMPv3 -- User Security Model |url=http://www.drdobbs.com/snmpv3-user-security-model/199100972 |access-date=2019-03-09 |publisher=Dr. Dobbs}}</ref>

==== 64-bit counters ====
SNMP version 2 introduces the option for 64-bit data counters. Version 1 was designed only with 32-bit counters, which can store integer values from zero to 4.29 billion (precisely {{val|4,294,967,295}}). A 32-bit version 1 counter cannot store the maximum speed of a 10 gigabit or larger interface, expressed in bits per second. Similarly, a 32-bit counter tracking statistics for a 10 gigabit or larger interface can roll over back to zero again in less than one minute, which may be a shorter time interval than a counter is polled to read its current state. This would result in lost or invalid data due to the undetected value rollover, and corruption of trend-tracking data.

The 64-bit version 2 counter can store values from zero to 18.4 quintillion (precisely 18,446,744,073,709,551,615) and so is currently unlikely to experience a counter rollover between polling events. For example, 1.6 [[terabit Ethernet]] is predicted to become available by 2025. A 64-bit counter incrementing at a rate of 1.6 trillion bits per second would be able to retain information for such an interface without rolling over for 133 days.