Technical Tip: How to prevent SNMPD crashes caused by duplicate SNMP indexes in virtual domains

[ekarim]

Description	This article describes how to resolve recurring SNMPD process crashes caused by misconfiguration or by migration from several firewalls to a single multi‑VDOM firewall, which can make the firewall unreachable via SNMP.
Scope	FortiOS.
Solution	The issue is caused by a duplicate snmp-index in the vdom-property, as shown below: config system vdom-property edit "vdom_1" set description "property limits for vdom vdom_1" set snmp-index 11 next edit "vdom_2" set description "property limits for vdom vdom_2" set snmp-index 6 <<<<<<<<< first next edit "vdom_3" set description "property limits for vdom vdom_3" set snmp-index 10 next edit "vdom_4" set description "property limits for vdom vdom_4" set snmp-index 5 next edit "vdom_5" set description "property limits for vdom vdom_5" set snmp-index 6 <<<<<<<<< second next end Below is the crashlog: diagnose debug crashlog read 15181: <00567> firmware FortiGate-3400E v7.2.12,build1761b1761,250909 (GA.M) (Release) 15182: <00567> application snmpd 15183: <00567> *** signal 6 (Aborted) received *** 15184: <00567> Register dump: 15185: <00567> RAX: 0000000000000000 RBX: 00007f517de13040 15186: <00567> RCX: ffffffffffffffff RDX: 0000000000000000 15187: <00567> R08: 0000000000000000 R09: 00007fff06806bf0 15188: <00567> R10: 0000000000000008 R11: 0000000000000246 15189: <00567> R12: 00000000018a2a80 R13: 00007fff06807bb0 15190: <00567> R14: 0000000000000000 R15: 00000000108196d0 15191: <00567> RSI: 00007fff06806bf0 RDI: 0000000000000002 15192: <00567> RBP: 00007fff06806e70 RSP: 00007fff06806bf0 15193: <00567> RIP: 00007f51806bfe41 EFLAGS: 0000000000000246 15194: <00567> CS: 0033 FS: 0000 GS: 0000 15195: <00567> Trap: 0000000000000000 Error: 0000000000000000 15196: <00567> OldMask: 0000000002000000 15197: <00567> CR2: 0000000000000000 15198: <00567> stack: 0x7fff06806bf0 - 0x7fff06808f10 15199: <00567> Backtrace: 15200: <00567> [0x7f51806bfe41] => /usr/lib/x86_64-linux-gnu/libc.so.6 15201: (gsignal+0x00000141) liboffset 00038e41 15202: <00567> [0x7f51806a9557] => /usr/lib/x86_64-linux-gnu/libc.so.6 15203: (abort+0x00000123) liboffset 00022557 15204: <00567> [0x0167111c] => /bin/snmpd 15205: <00567> [0x7f51806bfec0] => /usr/lib/x86_64-linux-gnu/libc.so.6 liboffset 15206: 00038ec0 15207: <00567> [0x018a3ae3] => /bin/snmpd 15208: <00567> [0x018a2be7] => /bin/snmpd 15209: <00567> [0x016730b7] => /bin/snmpd 15210: <00567> [0x02b3123f] => /bin/snmpd 15211: <00567> [0x02b3006f] => /bin/snmpd 15212: <00567> [0x02b2facd] => /bin/snmpd 15213: <00567> [0x02ae6ae2] => /bin/snmpd 15214: <00567> [0x02ae6649] => /bin/snmpd 15215: <00567> [0x02ae849c] => /bin/snmpd 15216: <00567> [0x02ae82f7] => /bin/snmpd 15217: <00567> [0x02ae8901] => /bin/snmpd 15218: <00567> [0x0167744a] => /bin/snmpd 15219: <00567> [0x01677119] => /bin/snmpd 15220: <00567> [0x01670c1f] => /bin/snmpd 15221: <00567> [0x0044bd7f] => /bin/snmpd 15222: <00567> [0x00451358] => /bin/snmpd 15223: <00567> [0x00451c46] => /bin/snmpd 15224: <00567> [0x00454388] => /bin/snmpd 15225: <00567> [0x00454de9] => /bin/snmpd 15226: <00567> [0x7f51806aae1b] => /usr/lib/x86_64-linux-gnu/libc.so.6 15227: (__libc_start_main+0x000000eb) liboffset 00023e1b 15228: <00567> [0x004475da] => /bin/snmpd 15229: <00567> fortidev 6.0.2.0008 15230: the killed daemon is /bin/snmpd: status=0x6 15231: snmpd watchdog timeout 15232: snmpd previously crashed 1 times. The last crash was at  The snmp-index must be unique for every virtual domain. Below is the range of possible values: Parameter  Description Type Size Default snmp-index Permanent SNMP Index of the vdom(1-2147483647) integer Minimum value:1 Maximum value:2147483647 0