Last Modified: Mar 04, 2026
Affected Product(s):
BIG-IP TMOS
Known Affected Versions:
17.5.0, 17.5.1, 17.5.1.2, 17.5.1.3, 17.5.1.4, 17.5.1.5
Opened: Feb 27, 2026 Severity: 3-Major
If a custom MIB OID is being serviced and snmpd crashes or is aborted snmpd can fail to restart. After crash or abort, snmpd continuously restarts with errors and cannot bind to port 161: Error: "Error opening specified endpoint tcp6:161"
SNMP monitoring unavailable until child processes terminate
1. System using custom MIB OIDs that spawn child processes (via TCL exec) 2. Custom MIB scripts execute long-running commands (tmsh etc), and one of these custom MIB OIDs is being serviced. 3. snmpd crashes or is aborted by software watchdog after no heartbeat for 300s or more. This could happen on a system that is thrashing due to memory starvation for instance. 4. child processes still executing even though parent process snmpd has died.
Identify processes holding port 161: ss -lnp | grep :161 lsof -i :161 Kill orphaned processes (not current snmpd PID): SNMPD_PID=$(pidof snmpd) ORPHANS=$(lsof -t -i :161 | grep -v "^${SNMPD_PID}$") kill -9 $ORPHANS Restart snmpd: bigstart restart snmpd
None