1.171. net-snmp

Updated net-snmp packages that resolve several issues are now available for Red Hat Enterprise Linux 6.
SNMP (Simple Network Management Protocol) is a protocol used for network management. The NET-SNMP project includes various SNMP tools: an extensible agent, an SNMP library, tools for requesting or setting information from SNMP agents, tools for generating and handling SNMP traps and a version of the netstat command which uses SNMP. This package contains the snmpd and snmptrapd daemons, documentation, etc.

Bug Fixes

BZ#616336, BZ#616764
The IP-MIB::ipAddressTable did not support SNMP SET operation, which enables adding or deleting rows in the IP address table. As a result IPv4 or IPv6 addresses on interfaces could neither be created or removed. The updated packages enhance IP-MIB::ipAddressTable with these functions as per RFC 4293 mandates.
Under certain conditions, and especially on networks with high traffic, snmpd wrote a lot of "c64 32 bit check failed" and "netsnmp_assert 1 == new_val->high failed" messages to the system log. Although these messages are harmless and not indicative of a serious error, they could potentially fill the system log quickly. This update suppresses these spurious messages in favour of more meaningful and specific error messages, which are written to the system log only once.
The SNMP daemon did not properly handle netlink sockets when forking to background and becoming a daemon. It could therefore not process incoming notifications from kernel regarding changes in IP-MIB::ipAddressPrefixTable. The updated package fixes the socket processing to ensure SNMP deamon handles incoming kernel notifications and updates ipAddressPrefixTable in runtime.
The SNMP daemon did not detect and notify newly added or activated interfaces in IPV6-MIB::627564ipv6IfTable. The updated package properly refreshes the table when new interface appears.
The implementation of BRIDGE-MIB was enhanced with Virtual LANs (RFC 4363).
The snmpwalk utility did not perform correct OID comparison and printed additional objects when walking through an OID subtree. The updated package fixed the OID comparison so that snmpwalk prints only the objects from requested subtree.
The SNMP daemon 'snmpd', returned incorrect value of either "0.1" or 1.3" for sysObjectID. This update fixes the value of this OID so it returns the correct value, "".


The Net-SNMP source RPM package failed to compile on machine incase of a disabled IPv6 networking stack since the built-in test suite requires a working IPv6. The updated package correctly recovers from a disabled IPv6 stack and compiles successfully.
The problem was that in some cases SNMP daemon 'snmpd', wrongly retyped pointers to integer data when processing SMUX packets resulting in a freeze. The pointer operations were fixed in the updated package to avoid snmpd freeze while processing SMUX packets.
The snmpd daemon handled incorrectly internal list of SMUX registrations, which could result in snmpd crash when processing SMUX messages. The updated package fixes the list handling and does not crash when processing SMUX messages.
The snmpd daemon did not properly initialize it's structures for IP-MIB::ipSystemStatsTable and IP-MIB::ipIfStatsTable properly. It returned this error message "looks like a 64bit wrap, but prev!=new" to log if a counter in these tables got larger than 32bits. The updated packages fixes initialization of the tables and ensures that the aforementioned message should not appear in snmpd log.
All users of net-snmp are advised to upgrade to these updated packages, which resolve these issues.
Updated net-snmp packages that fix one bug are now available for Red Hat Enterprise Linux 6 Extended Update Support.
The net-snmp packages provide a generic client library, a suite of command-line tools, an extensible SNMP agent, Perl modules, and Python modules to use and deploy the Simple Network Management Protocol (SNMP).

Bug Fix

Previously, the snmpd daemon did not verify the result of reading from a network socket in the SMUX (SNMP multiplexing) module. Consequently, snmpd was sometimes unable to close erroneous SMUX sessions, because it failed to detect some network errors. With this update, the snmpd daemon has been adapted to properly detect errors when reading from a SMUX socket and it now reacts to these errors properly.
Users of net-snmp are advised to upgrade to these updated packages, which fix this bug.