Ошибка snmp связи no response

I am trying to monitor network devices in our company using SCOM. So far the devices are not responding to SNMP request. These devices support SNMP. Firewall is not an issue since the monitoring server is already in the company’s network. Trying the command below gave the following result for one device:

~$ snmpget -v 1 -c ro345iu5672 11.248.154.10 .1.3.6.1.2.1.1.1.0
Timeout: No Response from 11.248.154.10.

Additional research suggested that the target SNMP device needs to enable the whole system MIB/OID-tree to be discoverable in SCOM. If any of the following OIDs are missing, you will not be able to discover the device:

• 1.3.6.1.2.1.1.1.0 --> system.sysDescr
• 1.3.6.1.2.1.1.2.0 --> system.sysObjectID
• 1.3.6.1.2.1.1.4.0 --> system.sysContact
• 1.3.6.1.2.1.1.5.0 --> system.sysName
• 1.3.6.1.2.1.1.6.0 --> system.sysLocation

How can I enable these OID’s for a network device?

asked May 12, 2016 at 10:21

answered May 12, 2016 at 11:02

if I just do that command I get this:

tim@cacti:~$ snmpget
No hostname specified.
USAGE: snmpget [OPTIONS] AGENT OID [OID]…

Version: 5.8
Web: http://www.net-snmp.org/
Email: net-snmp-coders@lists.sourceforge.net

OPTIONS:
-h, —help display this help message
-H display configuration file directives understood
-v 1|2c|3 specifies SNMP version to use
-V, —version display package version number
SNMP Version 1 or 2c specific
-c COMMUNITY set the community string
SNMP Version 3 specific
-a PROTOCOL set authentication protocol (MD5|SHA|SHA-224|SHA-256|SHA-384|SHA-512)
-A PASSPHRASE set authentication protocol pass phrase
-e ENGINE-ID set security engine ID (e.g. 800000020109840301)
-E ENGINE-ID set context engine ID (e.g. 800000020109840301)
-l LEVEL set security level (noAuthNoPriv|authNoPriv|authPriv)
-n CONTEXT set context name (e.g. bridge1)
-u USER-NAME set security name (e.g. bert)
-x PROTOCOL set privacy protocol (DES|AES)
-X PASSPHRASE set privacy protocol pass phrase
-Z BOOTS,TIME set destination engine boots/time
General communication options
-r RETRIES set the number of retries
-t TIMEOUT set the request timeout (in seconds)
Debugging
-d dump input/output packets in hexadecimal
-D[TOKEN[,…]] turn on debugging output for the specified TOKENs
(ALL gives extremely verbose debugging output)
General options
-m MIB[:…] load given list of MIBs (ALL loads everything)
-M DIR[:…] look in given list of directories for MIBs
(default: /home/tim/.snmp/mibs:/usr/share/snmp/mibs:/usr/share/snmp/mibs/iana:/usr/share/snmp/mibs/ietf)
-P MIBOPTS Toggle various defaults controlling MIB parsing:
u: allow the use of underlines in MIB symbols
c: disallow the use of «—» to terminate comments
d: save the DESCRIPTIONs of the MIB objects
e: disable errors when MIB symbols conflict
w: enable warnings when MIB symbols conflict
W: enable detailed warnings when MIB symbols conflict
R: replace MIB symbols from latest module
-O OUTOPTS Toggle various defaults controlling output display:
0: print leading 0 for single-digit hex characters
a: print all strings in ascii format
b: do not break OID indexes down
e: print enums numerically
E: escape quotes in string indices
f: print full OIDs on output
n: print OIDs numerically
p PRECISION: display floating point values with specified PRECISION (printf format string)
q: quick print for easier parsing
Q: quick print with equal-signs
s: print only last symbolic element of OID
S: print MIB module-id plus last element
t: print timeticks unparsed as numeric integers
T: print human-readable text along with hex strings
u: print OIDs using UCD-style prefix suppression
U: don’t print units
v: print values only (not OID = value)
x: print all strings in hex format
X: extended index format
-I INOPTS Toggle various defaults controlling input parsing:
b: do best/regex matching to find a MIB node
h: don’t apply DISPLAY-HINTs
r: do not check values for range/type legality
R: do random access to OID labels
u: top-level OIDs must have ‘.’ prefix (UCD-style)
s SUFFIX: Append all textual OIDs with SUFFIX before parsing
S PREFIX: Prepend all textual OIDs with PREFIX before parsing
-L LOGOPTS Toggle various defaults controlling logging:
e: log to standard error
o: log to standard output
n: don’t log at all
f file: log to the specified file
s facility: log to syslog (via the specified facility)

(variants)
[EON] pri: log to standard error, output or /dev/null for level ‘pri’ and above
[EON] p1-p2: log to standard error, output or /dev/null for levels ‘p1’ to ‘p2’
[FS] pri token: log to file/syslog for level ‘pri’ and above
[FS] p1-p2 token: log to file/syslog for levels ‘p1’ to ‘p2’
-C APPOPTS Set various application specific behaviours:
f: do not fix errors and retry the request
tim@cacti:~$

Read the man pages or documentation. Just follow your nose. Another option, maybe easier is this:

snmpwalk -c public -v2c hostname .1.3

That should spew a lot of data. The -c is the community string and of course the hostname is the hostname of the server.

tim@cacti:~$ snmpwalk -c public -v2c 10.41.1.3 .1.3
Timeout: No Response from 10.41.1.3
tim@cacti:~$

tim@cacti:~$ snmpwalk -c public -v2c 10.41.1.3
Timeout: No Response from 10.41.1.3
tim@cacti:~$

and firewall been turned off

I replaced hostname for where the ip address of the machine is

I am running Nagios Core 4.2.2
snmpwalk on the localhost returns information on MIB.
snmpwalk run against a switch with snmp turned on returns a timeout message.
All thing being equal shouldn’t I get some response besides timeout?

# snmpwalk -v 1 -c public localhost
SNMPv2-MIB::sysDescr.0 = STRING: Linux nagios.mynetwork.local 2.6.32-642.el6.x86_64
(the rest remove to save space)

# snmpwalk -v 1 -c public 10.30.25.11
Timeout: No Response from 10.30.25.11

# yum list installed
net-snmp.x86_64 1:5.5-60.el6 @base
net-snmp-libs.x86_64 1:5.5-60.el6 @base
net-snmp-perl.x86_64 1:5.5-60.el6 @base
net-snmp-utils.x86_64 1:5.5-60.el6 @base
(the rest remove to save space)

Thanks for any guidance

~hbackus

Yes, you should be getting a response assuming everything is equal.

Is the device only doing v1? 2c is pretty common and I’d try running the command with the «-v 2c» option as well.

There could also be a firewall between the devices preventing communication over UDP port 161. Can you verify on the end device if the SNMP traffic is even making it over?

Thanks for the kind response. Here is what I have uncovered so far.

It is obvious at this point that I do not know all the ins and outs on setting up SNMP.
Telling snmpwalk to use version 1 or version 2c does not change the message from the Nagios server running snmpwalk. «Timeout: No response from (ip_address)».

There is no firewall between the systems but they are on separate LAN segments.

I setup a packet capture on a span port for the server and I see the SNMP “get-next-request” made by the Nagios snmpwalk command.
I also see a return frame with «Error-status (no-error)» in the «SNMP data section» of the capture.

So if the request is going out and the reply is coming back, what would I have miss-configured or failed to configure for SNMP at the Nagios server that would cause “Timeout: No response from (ip_address)” to occurr?

I would take a closer look at the resposne. Try the following on XI’s command like to get a packet capture:

yum -y install tcpdump
tcpdump -s 0 -i any host 10.30.25.11 -w output.pcap

Let this run just long enough to run the snmpwalk command and then use CTRL+C to stop it. output.pcap can be viewed with wireshark and you can also PM it to me if you’d like a second pair of eyes to take a look.

Thanks for the tcpdump. The behavior it shows is strange.

First XI sends a snmpwalk request from source port 53373 to destination port 161 — so far so good

The destination appears to react to the request but not in an expected way and one that would produce the error message. Instead of sending a response to XI on port 53373, it sends XI a SNMP Trap on port 162 — This is the problem. In order for the SNMPWALK to work the destination should respond with a SNMP get-response message on port 53373 and not a snmpV2-trap message on port 162.’

You can see valid SNMP traffic with the example at https://wiki.wireshark.org/SampleCaptures#SNMP.

If you like weird, I may have just the thing for you.

I made no changes to the Nagios Core server.
I went to the switch I was running snmpwalk against and added a config line that said the snmp client was the Nagios server.
No change, the snmpwalk still timed out with no response as the error message.
I removed all the snmp configuration lines in the switch and then added them back in (in reverse order).
The configuration on the switch still showed the entries in the same order as before.
I ran snmpwalk and got a response.

SNMPv2-MIB::sysDescr.0 = STRING: Brocade Communications Systems, Inc.
SNMPv2-MIB::sysObjectID.0 = OID: SNMPv2-SMI::enterprises.1991.1.3.48.5.1
DISMAN-EVENT-MIB::sysUpTimeInstance = Timeticks: (1829683300) 211 days, 18:27:13.00
[lines removed for brevity]
SNMPv2-SMI::mib-2.192.1.1.1.0 = Gauge32: 50
SNMPv2-SMI::mib-2.192.1.1.2.0 = INTEGER: 2

Not sure if I needed all the lines in the configuration of the switch or not or if just removing them and adding them back “bumped” snmp enough that it started working.
I have about 15 more switch stacks to try this on, but I am leaving this one as is.

Thanks for your time and efforts. You can lock this thread down if you like.