196 Operating System WAGO-I/O-SYSTEM 750758-874/000-131 WAGO-I/O-IPC-C6ManualVersion 1.0.014.7.7 NFS ClientAn NFS client is integrated in the kernel, which enables the addition of remotedrives to one's own file system. To integrate a directory from a remote system, itis assigned to the Linux directory structure like a partition of a hard drive with thecommand mount. To use the NFS service, an NFS server with a correspondingreleased directory must be available on the remote PC. The integration of theremote directory into the file system of the I/O-IPC is done with the followingcommand:mount -t nfs -o nolock :// Verzeichnis>Example: > mount –t nfs –o nolock 192.168.1.12:/targetfs /mntThe drive /mnt is present when the I/O-IPC is delivered to the customer. It is usedto incorporate foreign drives. Access to the drive incorporated through NFS isconducted as if accessing a local directory. If drives are to be automaticallyincorporated during system startup, these can be entered in the directory /etc/rc.dusing a script.14.7.8 SNMP AgentThe "Simple Network Management Protocol" is used to monitor and controlnetwork components. During communication via SNMP, SNMP managers(clients) and SNMP agents (servers) come into use.The manager installed on a PC controls the agents installed on the I/O-IPC via aTCP/IP network. It can send queries to the I/O-IPC and receive responses. Theagent is used to capture and transmit device data (name, status, OIDs, etc.).The data of a device that the agent can access or modify are called SNMP objects.The SNMP objects are posted to the manager via the MIB file (ManagementInformation Base). OIDs (Object Identifier) are responsible for unique addressingof the individual information within an MIB.Use the Web-Based Management (WBM) to configure the SNMP agents of theI/O-IPC.The SNMP is supported in version 1, 2c and 3. The SNMP agent is disabled in theI/O-IPC as delivered. In SNMP versions 1 and 2c, the exchange of messages isdevice-related. This requires the IP address of the manager to be specified. This IPaddress makes communication between manager and network node possible. InSNMP version 3, exchanging messages is user-related. Each device that knowsthe passwords set via WBM may read or write values from the I/O-IPC. WithSNMPv3, the data can also be transmitted encrypted. This way, the requestedvalues and those to be written cannot be easily decoded by other on theETHERNET. Therefore, SNMPv3 is frequently used on security-relevantnetworks.
