Aktuelle Version vom 13. Mai 2024, 10:24 Uhr

SNMP can be used for status information via UDP (port 161). Supported SNMP commands are:

GET
GETNEXT
GETBULK
SET

To query via SNMP you need a Network Management System, such as HP OpenView, OpenNMS, Nagios etc., or the simple command line tools of NET-SNMP software. The device supports SNMP protocols v1, v2c and v3. If traps are enabled in the configuration, the device messages are sent as notifications (traps). SNMP Informs are not supported. SNMP Requests are answered with the same version with which they were sent. The version of the sent traps can be set in the configuration.

MIB Tables

The values that can be requested or changed by the device, the so-called "Managed Objects", are described in Management Information Bases (MIBs). These substructures are subordinate to so-called "OID" (Object Identifiers). An OID digit signifies the location of a value inside a MIB structure. Alternatively, each OID can be referred to with its symbol name (subtree name). The device's MIB table can be displayed as a text file by clicking on the link "MIB table" on the SNMP configuration page in the browser.

SNMP v1 and v2c

SNMP v1 and v2c authenticates the network requests by so-called communities. The SNMP request has to send along the so-called community public for queries (read access) and the community private for status changes (write access) . The SNMP communities are read and write passwords. In SNMP v1 and v2 the communities are transmitted unencrypted on the network and can be easily intercepted with IP sniffers within this collision domain. To enforce limited access we recommend the use of DMZ or IP-ACL.

SNMP v3

Because the device has no multiuser management, only one user (default name "standard") is detected in SNMP v3. From the User-based Security Model (USM) MIB variables, there is a support of "usmStats ..." counter. The "usmUser ..." variables will be added with the enhancement of additional users in later firmware versions. The system has only one context. The system accepts the context "normal" or an empty context.

Authentication

The algorithms "HMAC-MD5-96" and "HMAC-SHA-96" are available for authentication. In addition, the "HMAC-SHA-2" variants (RFC7630) "SHA-256", "SHA-384" and "SHA- 512" are implemented.
"SHA-384" and "SHA512" are calculated purely in software. If "SHA-384" or "SHA- 512" is set on the configuration page, the time for the key generation may take once up to approx. 45 seconds.
Encryption

The methods "DES", "3DES", "AES-128", "AES-192" and "AES-256" are supported in combination with "HMAC-MD5-96" and "HMAC-SHA-96." For the "HMAC-SHA-2" protocols, there is currently neither RFC nor draft that will allow for cooperation with an encryption.
While in the settings "AES-192" and "AES256" the key calculation is based on "draft-blumenthalphoto-aes-usm-04", the methods "AES 192-3DESKey" and "AES 256-3DESKey" utilize a key generation, which is also used in the "3DES" configuration ("draft-reeder-snmpv3-usm-3desede-00"). If one is not an SNMP expert, it is recommended to try in each case the settings with and without "...- 3DESKey".

Passwords

The passwords for authentication and encryption are stored only as computed hashes for security reasons. Thus it is, if at all, very difficult to infer the initial password. However, the hash calculation changes with the set algorithms. If the authentication or privacy algorithms are changed, the passwords must be re-entered in the configuration dialog.

Security

The following aspects should be considered:

If encryption or authentication is used, then SNMP v1 and v2c should be turned off. Otherwise the device could be accessed with it.
If only authentication is used, then the new "HMAC-SHA-2" methods are superior to the MD5 or SHA-1 hashing algorithms. Since only SHA-256 is accelerated in hardware, and SHA-384 and SHA-512 are calculated purely in software, one should normally select SHA-256. From a cryptographic point of view, the security of SHA-256 is sufficient for today's usage.
For SHA-1, there are a little less attack scenarios than MD5. If in doubt, SHA-1 is preferable.
Encryption "DES" is considered very unsafe, use only in an emergency for reasons of compatibility!
For cryptologists it's a debatable point whether "HMAC-MD5-96" and "HMAC-SHA- 96" can muster enough entropy for key lengths of "AES-192" or "AES-256".
From the foregoing considerations, we would recommended at present "HMACSHA-96" with "AES-128" as authentication and encryption method.

Change in Trap Design

In older MIB tables, a separate trap was defined for each combination of an event and a port number. This results in longer lists of trap definitions for the devices. For example, from epc8221SwitchEvtPort1 to epc8221SwitchEvtPort12. Since new firmware versions can generate many more different events, this behavior quickly produces several hundred trap definitions. To limit this overabundance of trap definitions, the trap design has been changed to create only one specific trap for each event type. The port or sensor number is now available in the trap as an index OID within the variable bindings.

In order to recognize this change directly, the "Notification" area in the MIB table has been moved from sysObjectID.0 to sysObjectID.3. This way, unidentified events are generated until the new MIB table is imported. For compatibility reasons, SNMP v1 traps are created in the same way as before.

NET-SNMP

NET-SNMP provides a very widespread collection of SNMP command-line tools (snmpget, snmpset, snmpwalk etc.) NET-SNMP is among others available for Linux and Windows. After installing NET-SNMP you should create the device-specific MIB of the device in NET-SMP share directory, e.g. after

c:\usr\share\snmp\mibs
or

/usr/share/snmp/mibs

So later you can use the 'subtree names' instead of OIDs:

Name: snmpwalk -v2c -mALL -c public 192.168.1.232 gudeads
OID: snmpwalk -v2c -mALL -c public 192.168.1.232 1.3.6.1.4.1.28507

NET-SNMP Examples

These examples refer to Gude devices that have switchable ports.

Query Power Port 1 switching state:

snmpget -v2c -mALL -c public 192.168.1.232 epc822XPortState.1

Switch on Power Port 1:

snmpset -v2c -mALL -c private 192.168.1.232 epc822XPortState.1 integer 1

MIB table

Below is a table of all device-specific OID 's which can be accessed via SNMP. In the numerical representation of the OID the prefix " 1.3.6.1.4.1.28507 " (Gude Enterprise OID) was omitted at each entry in the table to preserve space.
The example for a complete OID would be "1.3.6.1.4.1.28507.85.1.1.1.1". A distinction is made in SNMP OID 's in between tables and scalars. OID scalar have the extension ".0" and only specify a value. In SNMP tables the "x" is replaced by an index (1 or greater) to address a value from the table.
Good to know: In the web server on every device you can find the MIB table under the SNMP tab. You can also download the MIB tables on our website under Downloads.

Please note that not all commands are available for all of our devices.
This table was created for our Expert Power Control 8045.

Name	Description	OID	Type	Acc.
epc8045TrapCtrl	0 = off 1 = Ver. 1 2 = Ver. 2c 3 = Ver. 3	87.1.1.1.1.0	Integer32	RW
epc8045TrapIPIndex	A unique value, greater than zero, for each receiver slot.	.87.1.1.1.2.1.1.x	Integer32	RO
epc8045TrapAddr	DNS name or IP address specifying one Trap receiver slot. A port can optionally be specified: 'name:port' An empty string disables this slot.	.87.1.1.1.2.1.2.x	OCTETS	RW
epc8045portNumber	The number of Relay Ports	.87.1.3.1.1.0	Integer32	RO
epc8045PortIndex	A unique value, greater than zero, for each Relay Port.	.87.1.3.1.2.1.1.x	Integer32	RO
epc8045PortName	A textual string containing name of a Relay Port.	OCTETS	RW
epc8045PortState	current state of a Relay Port	.87.1.3.1.2.1.3.x	INTEGER	RW
epc8045PortSwitchCount	The total number of switch actions ocurred on a Relay Port. Does not count switch commands which will not switch the ralay state, so just real relay switches are displayed here.	.87.1.3.1.2.1.4.x	Integer32	RO
epc8045PortStartupMode	set Mode of startup sequence (off, on , remember last state)	.87.1.3.1.2.1.5.x	INTEGER	RW
epc8045PortStartupDelay	Delay in sec for startup action	.87.1.3.1.2.1.7.x	Integer32	RW
epc8045PortRepowerTime	Delay in sec for repower port after switching off	.87.1.3.1.2.1.7.x	Integer32	RW
epc8045PortResetDuration	Delay in sec for turning Port on again after Reset action	.87.1.3.1.2.1.8.x	Integer32	RW
epc8045Buzzer	turn Buzzer on and off	.87.1.3.10.0	Integer32	RW
epc8045ActivePowerChan	Number of suppported Power Channels.	.87.1.5.1.1.0	Unsigned32	RO
epc8045PowerIndex	Index of Power Channel entries	.87.1.5.1.2.1.1.x	Integer32	RO
epc8045ChanStatus	0 = data not active, 1 = data valid	.87.1.5.1.2.1.2.x	Integer32	RO
epc8045AbsEnergyActive	Absolute Active Energy counter.	.87.1.5.1.2.1.3.x	Gauge32	RO
epc8045PowerActive	Active Power	.87.1.5.1.2.1.4.x	Integer32	RO
epc8045Current	Actual Curent on Power Channel.	.87.1.5.1.2.1.5.x	Gauge32	RO
epc8045Voltage	Actual Voltage on Power Channel	.87.1.5.1.2.1.6.x	Gauge32	RO
epc8045Frequency	Frequency of Power Channel	.87.1.5.1.2.1.7.x	Gauge32	RO
epc8045PowerFactor	Power Factor of Channel between -1.0 and 1.00	.87.1.5.1.2.1.8.x	Integer32	RO
epc8045Pangle	Phase Angle between Voltage and L Line Current between -180.0 and 180.0	.87.1.5.1.2.1.9.x	Integer32	RO
epc8045PowerApparent	L Line Mean Apparent Power	.87.1.5.1.2.1.10.x	Integer32	RO
epc8045PowerReactive	L Line Mean Reactive Power	.87.1.5.1.2.1.11.x	Integer32	RO
epc8045AbsEnergyReactive	Absolute Reactive Energy counter.	.87.1.5.1.2.1.12.x	Gauge32	RO
epc8045AbsEnergyActiveResettable	Resettable Absolute Active Energy counter. Writing '0' resets all resettable counter.	.87.1.5.1.2.1.13.x	Gauge32	RW
epc8045AbsEnergyReactiveResettable	Resettable Absolute Reactive Energy counter.	.87.1.5.1.2.1.14.x	Gauge32	RO
epc8045ResetTime	Time in seconds since last Energy Counter reset.	Gauge32	RO
epc8045ForwEnergyActive	Forward Active Energy counter.	.87.1.5.1.2.1.16.x	Gauge32	RO
epc8045ForwEnergyReactive	Forward Reactive Energy counter.	.87.1.5.1.2.1.17.x	Gauge32	RO
epc8045ForwEnergyActiveResettable	Resettable Forward Active Energy counter.	.87.1.5.1.2.1.18.x	Gauge32	RO
epc8045ForwEnergyReactiveResettable	Resettable Forward Reactive Energy counter.	.87.1.5.1.2.1.19.x	Gauge32	RO
epc8045RevEnergyActive	Reverse Active Energy counter.	.87.1.5.1.2.1.20.x	Gauge32	RO
epc8045RevEnergyReactive	Reverse Reactive Energy counter.	.87.1.5.1.2.1.21.x	Gauge32	RO
epc8045RevEnergyActiveResettable	Resettable Reverse Active Energy counter.	.87.1.5.1.2.1.21.x	Gauge32	RO
epc8045RevEnergyActiveResettable	Resettable Reverse Active Energy counter.	.87.1.5.1.2.1.22.x	Gauge32	RO
epc8045RevEnergyReactiveResettable	Resettable Reverse Reactive Energy counter.	.87.1.5.1.2.1.23.x	Gauge32	RO
epc8045ResidualCurrent	Actual Residual Current on Power Channel. According Type A IEC 60755. Only visible on models that support this feature.	.87.1.5.1.2.1.24.x	Unsigned32	RO
epc8045LineSensorName	A textual string containing name of a Line Sensor	.87.1.5.1.2.1.100.x	OCTETS	RW
epc8045OVPIndex	None	.87.1.5.2.1.1.x	Integer32	RO
epc8045OVPStatus	shows the status of the built-in Overvoltage Protection	.87.1.5.2.1.2.x	INTEGER	RO
epc8045spActivePowerChan	Number of Single Port Power Channels. Value is zero on EPC 8220 series.	.87.1.5.5.1.0	Unsigned32	RO
epc8045spPowerIndex	Index of Single Port Power Channel entries. Indices 0-5 mean Ports A1 to A6, 6-11 are Ports B1 to B6.	.87.1.5.5.2.1.1.x	Integer32	RO
epc8045spChanStatus	0 = data not active, 1 = data valid	.87.1.5.5.2.1.2.x	Integer32	RO
epc8045spAbsEnergyActive	Absolute Active Energy counter.	.87.1.5.5.2.1.3.x	Gauge32	RO
epc8045spPowerActive	Active Power	.87.1.5.5.2.1.4.x	Integer32	RO
epc8045spCurrent	Actual Curent on Power Channel.	.87.1.5.5.2.1.5.x	Gauge32	RO
epc8045spVoltage	Actual Voltage on Power Channel	.87.1.5.5.2.1.6.x	Gauge32	RO
epc8045spFrequency	Frequency of Power Channel	.87.1.5.5.2.1.7.x	Gauge32	RO
epc8045spPowerFactor	Power Factor of Channel between -1.0 and 1.00	.87.1.5.5.2.1.8.x	Integer32	RO
epc8045spPangle	Phase Angle between Voltage and L Line Current between -180.0 and 180.0	.87.1.5.5.2.1.9.x	Integer32	RO
epc8045spPowerApparent	L Line Mean Apparent Power	.87.1.5.5.2.1.10.x	Integer32	RO
epc8045spPowerReactive	L Line Mean Reactive Power	.87.1.5.5.2.1.11.x	Integer32	RO
epc8045spAbsEnergyReactive	Absolute Reactive Energy counter.	.87.1.5.5.2.1.12.x	Gauge32	RO
epc8045spAbsEnergyActiveResettable	Resettable Absolute Active Energy counter. Writing '0' resets all resettable counter.	.87.1.5.5.2.1.13.x	Gauge32	RW
epc8045spAbsEnergyReactiveResettable	Resettable Absolute Reactive Energy counter.	.87.1.5.5.2.1.14.x	Gauge32	RO
epc8045spResetTime	Time in seconds since last Energy Counter reset.	.87.1.5.5.2.1.15.x	Gauge32	RO
epc8045spForwEnergyActive	Forward Active Energy counter.	.87.1.5.5.2.1.16.x	Gauge32	RO
epc8045spForwEnergyReactive	Forward Reactive Energy counter.	.87.1.5.5.2.1.17.x	Gauge32	RO
epc8045spForwEnergyActiveResettable	Resettable Forward Active Energy counter.	.87.1.5.5.2.1.18.x	Gauge32	RO
epc8045spForwEnergyReactiveResettable	Resettable Forward Reactive Energy counter.	.87.1.5.5.2.1.19.x	Gauge32	RO
epc8045spRevEnergyActive	Reverse Active Energy counter.	.87.1.5.5.2.1.20.x	Gauge32	RO
epc8045spRevEnergyReactive	Reverse Reactive Energy counter.	.87.1.5.5.2.1.21.x	Gauge32	RO
epc8045spRevEnergyActiveResettable	Resettable Reverse Active Energy counter.	.87.1.5.5.2.1.22.x	Gauge32	RO
epc8045spRevEnergyReactiveResettable	Resettable Reverse Reactive Energy counter.	.87.1.5.5.2.1.23.x	Gauge32	RO
epc8045CPUSensorVsystem	System Voltage on CPU Board	.87.1.5.14.1.0	Gauge32	RO
epc8045CPUSensorVaux	Auxiliary Voltage on CPU Board	.87.1.5.14.2.0	Gauge32	RO
epc8045CPUSensorVmain	Main Voltage on CPU Board	.87.1.5.14.3.0	Gauge32	RO
epc8045CPUSensorTcpu	Temperature on CPU Board	.87.1.5.14.4.0	Integer32	RO
epc8045NTPTimeValid	Show if valid Time is received	.87.1.5.15.1.0	INTEGER	RO
epc8045NTPUnixTime	show received NTP time as unixtime (secs since 1 January 1970)	.87.1.5.15.2.0	Unsigned32	RO
epc8045NTPLastValidTimestamp	show seconds since last valid NTP timestamp received	.87.1.5.15.3.0	Unsigned32	RO
epc8045RCMBInfoIndex	Index of RCMB Info entries	.87.1.5.16.1.1.x	Integer32	RO
epc8045RCMBCurrentRMS	Actual Residual Current RMS on Power Channel. According Type B IEC 60755. Only visible on models that support this feature.	.87.1.5.16.1.2.x	Unsigned32	RO
epc8045RCMBlCurrentDC	Actual Residual Current DC on Power Channel. According Type B IEC 60755. Only visible on models that support this feature.	.87.1.5.16.1.3.x	Unsigned32	RO
epc8045RCMBOutputRMS	shows the output S1 of the RCMB module	.87.1.5.16.1.4.x	INTEGER	RO
epc8045RCMBOutputDC	shows the output S2 of the RCMB module	.87.1.5.16.1.5.x	INTEGER	RO
epc8045RCMBModuleStatus	RCMB Module Status Word	.87.1.5.16.1.6.x	Unsigned32	RO
epc8045SensorIndex	None	.87.1.6.1.1.1.x	Integer32	RO
epc8045TempSensor	actual temperature	.87.1.6.1.1.2.x	Integer32	RO
epc8045HygroSensor	actual humidity	.87.1.6.1.1.3.x	Integer32	RO
epc8045AirPressure	actual air pressure	.87.1.6.1.1.5.x	Integer32	RO
epc8045DewPoint	dew point for actual temperature and humidity	.87.1.6.1.1.6.x	Integer32	RO
epc8045DewPointDiff	difference between dew point and actual temperature (Temp - DewPoint)	.87.1.6.1.1.7.x	Integer32	RO
epc8045ExtSensorName	A textual string containing name of a external Sensor	.87.1.6.1.1.32.x	OCTETS	RW
epc8045ExtActiveInputs	Number of suppported Input Channels.	.87.1.6.2.1.0	Unsigned32	RO
epc8045ExtInputIndex	None	.87.1.6.2.2.1.1.x	Unsigned32	RO
epc8045ExtInput	Input state of device	.87.1.6.2.2.1.2.x	INTEGER	RO
epc8045ExtInputName	A textual string containing name of the Input	.87.1.6.2.2.1.32.x	OCTETS	RW
epc8045ExtInputPortNum	Number of external Sensor Port when value greater zero, else device built-in Input.	.87.1.6.2.2.1.33.x	Integer32	RO
epc8045ExtInputBlockIndex	Either index of device built-in Input, or index of Input in external sensor.	.87.1.6.2.2.1.34.x	Integer32	RO

@@ Zeile 76: / Zeile 76: @@
 <br />The example for a complete OID would be "1.3.6.1.4.1.28507.85.1.1.1.1". A distinction is made in SNMP OID 's in between tables and scalars. OID scalar have the extension ".0" and only specify a value. In SNMP tables the "x" is replaced by an index (1 or greater) to address a value from the table.
 <br />Good to know: In the web server on every device you can find the MIB table under the SNMP tab. You can also download the MIB tables on our website under Downloads.
+<br />
+<br />
+<br /> Please note that not all commands are available for all of our devices.
+<br /> This table was created for our Expert Power Control 8045.
+<br />
+<br />
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SNMP eng: Unterschied zwischen den Versionen