Which SNMP version do not support encryption?
What kind of version for authentication and encryption method does PRTG support in snmp v3 ? Show
In the case of SHA for authentication, does PRTG support SHA-2 and SHA-3? Are the following cases also supported? SHA-256, SHA-384, SHA-512. In the case of AES for encryption, does PRTG support AES-128, AES-192, and AES-256? authentication encryption snmp snmpv3 5 Replies Hello, currently SNMP supports only AES-128 Encryption. AES-192 and AES-256 are still not supported based on the Manual. Thanks for your reply. What about SHA ? Does PRTG support SHA-256, SHA-384, SHA-512 ? Hello Jonathan, we were doing a research with our developers. They mentioned we're still using an older version of this library, so there is no support for the authentication methods you mentioned at the moment. Hello, Most of our customers are using Cisco devices and they want to use the default AES-256 encryption. Is there a timeline for implementing AES-256 support? Thanks! We dont have an specific date at the moment. Disclaimer: The information in the Paessler Knowledge Base comes without warranty of any kind. Use at your own risk. Before applying any instructions please exercise proper system administrator housekeeping. You must make sure that a proper backup of all your data is available. Overview of SNMPThe Simple Network Management Protocol (SNMP) is used to manage network devices. There are various types of network devices and the management interfaces (such as command line interfaces) provided by different vendors vary from each other, making network management more complex. SNMP is developed to simplify network management. SNMP is widely used on TCP/IP networks for network management. It provides unified interfaces to implement unified management of network devices of different types from different vendors. SNMP has three versions: SNMPv1, SNMPv2c, and SNMPv3.
Components in an SNMP SystemAn SNMP system consists of four key components: network management system (NMS), SNMP agent, managed object, and management information base (MIB). The NMS manages network elements on a network. Each managed device contains an SNMP agent process, a MIB, and multiple managed objects. The NMS interacts with the SNMP agent on a managed device. When receiving an instruction from the NMS, the SNMP agent performs operations in the MIB on the managed device. Figure 1-1 Components in an SNMP system NMSThe NMS is a network manager that uses SNMP to manage and monitor network devices. The NMS software runs on NMS servers to implement the following functions:
SNMP AgentAn SNMP agent is a process running on a managed device. It maintains data on the managed device, responds to requests from the NMS, and returns management data to the NMS.
Managed ObjectA managed object is an object to be managed on a network device. A managed device may contain multiple managed objects, for example, a hardware component and parameters configured for the hardware or software (such as a routing protocol). MIBA MIB contains the variables that a managed device maintains. The MIB defines the attributes of the managed device, including the name, status, access rights, and data type of managed objects. The MIB can be regarded as an interface between the NMS and SNMP agent. Through this interface, the NMS queries and sets the variables maintained by a managed device. A MIB uses a tree structure to store data, as shown in Figure 1-2. A tree node indicates a managed object, which is uniquely identified by a path starting from the root. This path is called an object identifier (OID). For example, the OID of system is 1.3.6.1.2.1.1, and the OID of interfaces is 1.3.6.1.2.1.2. A subtree can be identified by the OID of the root node of the subtree. For example, the OID of the subtree with private as the root node is the OID of private, that is, {1.3.6.1.4}. Figure 1-2 OID tree You can specify the MIB objects that the NMS can access in MIB views. A MIB view is a subset of a MIB. You can set the status of objects in a MIB view to exclude or include. exclude indicates that the current view does not contain all nodes of the MIB subtree. include indicates that the current view contains all nodes of the MIB subtree. SNMP GetThe NMS can send get requests to an SNMP agent to obtain data, as shown in Figure 1-3. After receiving a get request, the SNMP agent executes the corresponding instruction in the MIB and sends the result to the NMS. SNMP get operations include Get, GetNext, and GetBulk. SNMPv1 does not support the GetBulk operation.
Figure 1-3 SNMP get operations SNMP Get PacketsFigure 1-4 shows the format of SNMPv1 and SNMPv2c get packets, which mainly consist of the version, community name, and SNMP protocol data unit (PDU). Packets of various SNMP operations are encapsulated in SNMP PDUs. Figure 1-4 Format of SNMPv1 and SNMPv2c get packets The fields in SNMPv1 and SNMPv2c get packets are as follows:
SNMPv2c get request packets sent by the device are obtained using a tool. Figure 1-5 shows an SNMPv2c GetRequest packet. Figure 1-6 shows an SNMPv2c GetNextRequest packet. Figure 1-7 shows an SNMPv2c GetBulkRequest packet. Figure 1-5 SNMPv2c GetRequest packet Figure 1-6 SNMPv2c GetNextRequest packet Figure 1-7 SNMPv2c GetBulkRequest packet Figure 1-8 shows the format of SNMPv3 get packets. The SNMP PDU format of SNMPv3 is the same as that of SNMPv2c. SNMPv3 support authentication, and the Context EngineID, Context Name, and SNMP PDU fields can be encrypted in SNMPv3 packets. Figure 1-8 Format of an SNMPv3 get packet The fields in an SNMPv3 get packet are as follows:
SNMPv3 provides an authentication mechanism, and therefore is recommended. SNMPv3 GetRequest packets sent by the device are obtained using a tool. Figure 1-9 shows an encrypted SNMPv3 GetRequest packet. Figure 1-10 shows an unencrypted SNMPv3 GetRequest packet. Figure 1-9 Encrypted SNMPv3 GetRequest packet Figure 1-10 Unencrypted SNMPv3 GetRequest packet Implementation of SNMP Get OperationsImplementations of get operations in different SNMP versions are similar. The only difference lies in that SNMPv3 supports identity authentication and encryption. The following uses the Get operation of SNMPv2c as an example. In this example, the NMS intends to use the read community name public to obtain the value of the sysContact object on a managed device. The procedure is as follows:
SNMP SetThe NMS can send set requests to an SNMP agent to complete configurations on the managed device, as shown in Figure 1-11. After receiving a set request, the SNMP agent executes the corresponding instruction in the MIB and sends the result to the NMS. Using the SNMP set operation, the NMS can configure one or more parameters for an SNMP agent. Figure 1-11 SNMP set operation SNMP Set PacketsFigure 1-12 shows the format of SNMPv1 and SNMPv2c set packets. Generally, information about the SNMPv3 set operation is encrypted and encapsulated in an SNMP PDU. The format of the SNMP PDU in an SNMPv3 set packet is the same as that in an SNMPv2c set packet. Figure 1-12 Format of SNMPv1 and SNMPv2c set packets The fields in SNMPv1 and SNMPv2c set packets are as follows:
Figure 1-13 shows an SNMPv2c SetRequest packet obtained by a tool. Figure 1-13 SNMPv2c SetRequest packet Implementation of the SNMP Set OperationImplementations of the set operation in different SNMP versions are similar. The only difference lies in that SNMPv3 supports identity authentication and encryption. The following uses the set operation of SNMPv3 as an example. In this example, the NMS intends to set the sysName object on a managed device to HUAWEI. The procedure is as follows:
SNMP TrapsSNMP traps are notification messages sent by an SNMP agent to inform the NMS of alarms or events generated by the device. In this way, the administrator can learn the running status of the device in a timely manner. There are two types of SNMP traps: trap and inform. SNMPv1 does not support inform. The difference between trap and inform is that, after an SNMP agent sends an alarm or event to the NMS through an InformRequest message, the NMS needs to reply with an InformResponse message, as shown in Figure 1-14. Figure 1-14 SNMP trap operation Format of SNMP TrapsFigure 1-15 shows the format of an SNMPv1 trap. Figure 1-15 Format of an SNMPv1 trap The fields in an SNMPv1 trap are as follows:
Figure 1-16 shows an SNMPv1 trap obtained by a tool. Figure 1-16 SNMPv1 trap Figure 1-17 shows the format of SNMPv2c trap and inform messages. Generally, information about the SNMPv3 trap and inform operations is encrypted and encapsulated in SNMP PDUs. The format of the SNMP PDU in an SNMPv3 trap or inform message is the same as that in an SNMPv2c trap or inform message. Figure 1-17 Format of an SNMPv2c trap or inform message The fields in an SNMPv2c trap or inform message are as follows:
SNMPv2c traps sent by the device are obtained using a tool. Figure 1-18 shows an SNMPv2c trap. Figure 1-19 shows an SNMPv2c inform message. Figure 1-18 SNMPv2c trap Figure 1-19 SNMPv2c inform message Implementation of SNMP TrapsImplementation of the trap operation Trap is a spontaneous activity of a managed device. The trap operation is not a basic operation that the NMS performs on the managed device. If a trap triggering condition is met on a managed device, the SNMP agent sends a trap to notify the NMS of the exception. In this way, the administrator can process the exception in a timely manner. For example, when a managed device completes a warm start, the SNMP agent sends a warmStart trap to the NMS. The SNMP agent sends a trap to the NMS only when a module on the managed device meets the trap triggering condition. This reduces management information exchanged between the NMS and managed devices. Implementation of the inform operation Inform is also a spontaneous activity of a managed device. In contrast to the trap operation, the inform operation requires an acknowledgement. After a managed device sends an InformRequest message to the NMS, the NMS returns an InformResponse message. If the managed device does not receive an acknowledgement, it performs the following operations:
Therefore, inform messages occupy more system resources than traps. SNMP Port NumbersSNMP packets are common UDP packets. SNMP defines two default port numbers:
Related InformationFor details about how to configure and use SNMP, see the following chapters in different documents: SNMP Configuration in the S12700 V200R013C00 Configuration Guide - Network Management and Monitoring SNMP Configuration in the CloudEngine 12800 and 12800E V200R005C10 Configuration Guide - Network Management and Monitoring SNMP Configuration in the Wireless Access Controller (AC and FITAP) V200R010C00 CLI-based Configuration Guide SNMP under "Configuration > Administrator Guide > System" in the HUAWEI USG6000, USG9500, and NGFW Module V500R005C00 Product Documentation SNMP Configuration under "Configuration > CLI-based Configuration > Network Management and Monitoring Configuration Guide" in the Huawei AR100, AR120, AR150, AR160, AR200, AR1200, AR2200, AR3200, and AR3600 V200R010 Product Documentation SNMP Configuration under "Configuration > System Management" in the NE20E-S V8R10C10SPC500 Product Documentation SNMP Configuration under "Configuration > System Management" in the NE40E V8R10C10SPC500 Product Documentation
Which of the following SNMP version does not support encryption?Currently, there are three versions of SNMP defined: SNMP v1 , SNMP v2c and SNMPv3. SNMPv3 adds security and remote configuration capabilities to the previous versions of SNMP. SNMP version 3 (v3) is not supported in Symantec Encryption Management Server (SEMS) 3.3.
Which version of SNMP uses encryption?SNMP version 3 adds both encryption and authentication, which can be used together or separately.
Is SNMP v3 encrypted?The SNMP Version 3 feature provides secure access to devices by authenticating and encrypting data packets over the network.
Does SNMP use encryption?SNMPv3 was recognised by the IETF in 2004. It adds a both encryption and authentication options to both prevent snooping and unauthorised access.
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