Lantronix UDS10 User Manual

Also see for Device Server UDS 10: User guide Hardware guide

Contents

Lantronix UDS10 User Manual Manual pdf 57 page image

57AA:: AAlltteerrnnaattiivvee WWaayyss ttoo AAssssiiggnn aann IIPP AAddddrreessssEarlier chapters describe how to assign a static IP address using DeviceInstaller,Web Manager, and Setup Mode (through a Telnet or serial connection). This sectioncovers other methods for assigning an IP address over the network.DHCPThe unit ships with a default IP address of 0.0.0.0, which automatically enablesDHCP. If a DHCP server exists on the network, it provides the unit with anIP address, gateway address, and subnet mask when the unit boots up.You can use the DeviceInstaller software to search the network for the DHCP-assigned IP address and add it to the list of devices retrieved.Note: This DHCP address does not appear in the unit’s Setup Mode or inWeb Manager. You can determine your unit’s DHCP-assigned IP address inMonitor Mode. When you enter Monitor Mode from the serial port withnetwork connection enabled (see Entering Monitor Mode Using the SerialPort on page 43) and issue the NC (Network Communication) command, yousee the unit’s IP configuration.AutoIPThe unit ships with a default IP address of 0.0.0.0, which automatically enablesAuto IP within the unit. AutoIP is an alternative to DHCP that allows hosts toautomatically obtain an IP address in smaller networks that may not have a DHCPserver. A range of IP addresses (from 169.254.0.1 to 169.254.255.1) has beenexplicitly reserved for AutoIP-enabled devices. Do not use this range of Auto IPaddresses over the Internet. If your unit cannot find a DHCP server, and you have not manually assignedan IP address to it, the unit automatically selects an address from the AutoIPreserved range. Then, your unit sends out a (ARP) request to other nodes onthe same network to see whether the selected address is being used. If the selected address is not in use, then the unit uses it for local subnetcommunication.  If another device is using the selected IP address, the unit selects anotheraddress from the AutoIP range and reboots. After reboot, the unit sends outanother ARP request to see if the selected address is in use, and so on.AutoIP does not replace DHCP. The unit continues to look for a DHCP server on thenetwork. If it finds a DHCP server, the unit switches to the DHCP server-providedaddress and reboots.Note: If a DHCP server is found, but it denies the request for an IP address,the unit does not attach to the network, but waits and retries.AutoIP can be disabled by setting the unit’s IP address to 0.0.1.0. This settingenables DHCP but disables AutoIP.