Hello,
I get an snmp protocol error response when attempting to `snmp get` certain
OIDs on various devices. However `tcpdump` shows that the device is actually
responding with the anticipated result but it appears snmp isn't able to parse
the response correctly? Any suggestions on how to troubleshoot further are
welcome.
I'm requesting the mntrFreq OID which is formatted as such:
Name: mntrFreq
OID: .1.3.6.1.4.1.35833.12.3.1
MIB: DB7000-MIB
Syntax: INTEGER32 (87100..108100)
Access: read-only
Status: current
DefVal:
Indexes:
Descr: "mntr Freq"
imac:/home/admin $ snmp get -v 2c -r 0 -c *redacted* udp:paint-receiver:161
.1.3.6.1.4.1.35833.12.3.1.0
snmp: get: Protocol error
imac:/home/admin $ doas tcpdump host paint-receiver
tcpdump: listening on bge0, link-type EN10MB
10:10:02.804614 192.168.0.4.21246 > paint-receiver.snmp: C=*redacted*
GetRequest(32) E:35833.12.3.1.0
10:10:03.231863 paint-receiver.snmp > 192.168.0.4.21246: C=*redacted*
GetResponse(40) E:35833.12.3.1.0=103500
The response of "103500" correlates to a frequency of 103.5 MHz which is the
anticipated response.
The same device responds correctly with a different OID:
Name: alias
OID: .1.3.6.1.4.1.35833.12.2.10.1
MIB: DB7000-MIB
Syntax: DISPLAYSTRING (SIZE(0..32))
Access: read-write
Status: current
DefVal:
Indexes:
Descr: "Alias name for the device"
imac:/home/admin $ snmp get -v 2c -r 0 -c *redacted* udp:paint-receiver:161
.1.3.6.1.4.1.35833.12.2.10.1.0
enterprises.35833.12.2.10.1.0 = STRING: DB7000: Paint Mt
tcpdump: listening on bge0, link-type EN10MB
11:45:04.009078 192.168.0.4.30426 > paint-receiver.snmp: C=*redacted*
GetRequest(33) E:35833.12.2.10.1.0
11:45:04.558528 paint-receiver.snmp > 192.168.0.4.30426: C=*redacted*
GetResponse(53) E:35833.12.2.10.1.0="DB7000: Paint Mt"
imac:/home/admin $ dmesg | head
OpenBSD 7.2 (GENERIC.MP) #0: Wed Oct 26 12:01:47 MDT 2022
r...@syspatch-72-amd64.openbsd.org:/usr/src/sys/arch/amd64/compile/GENERIC.MP
real mem = 4201062400 (4006MB)
avail mem = 4056354816 (3868MB)
random: good seed from bootblocks
mpath0 at root
scsibus0 at mpath0: 256 targets
mainbus0 at root
bios0 at mainbus0: SMBIOS rev. 2.4 @ 0xe0000 (60 entries)
bios0: vendor Apple Inc. version "99.0.0.0.0" date 06/13/2019
--
Byron Klippert
byronklipp...@ml1.net
c. 867-334-5179
