Enabling/Disabling The Dhcp Relay Support; Viewing A List Of Active Leases - Siemens RUGGEDCOM ROX II User Manual

Chapter 5
Setup and Configuration
Section 5.15.3

Enabling/Disabling the DHCP Relay Support

If DHCP relay (or Option 82) clients are used on the same subnet as the DHCP server, some clients will try to
renew a lease immediately after receiving it by requesting a renewal directly from the DHCP server. Because the
DHCP server is configured by default to only provide the lease through a relay agent configured with the current
Option 82 fields, the server sends the client a NAK protocol message to disallow the lease. Enabling Option
82 disables the NAK protocol message so that the renewal request sent from the DHCP relay agent (which the
DHCP server accepts since it has the correct Option 82 fields added) is the only message for which the client
receives a reply.
NOTE
Option 82 support should only be enabled If the DHCP server and clients are on the same subnet.
NOTE
The meaning of most Option 82 fields is determined by the DHCP relay client. To determine which
values are required by the client for special options, refer to the client documentation.
NOTE
DHCP relay support can also be enabled on an individual subnet. For more information, refer to
Section 5.15.7.3, "Configuring Subnet
To enable or disable DHCP relay support on the DHCP server, do the following:
1. Make sure the CLI is in Configuration mode.
2. Enable or disable DHCP relay support by typing:
services dhcpserver options option82
Type commit and press Enter to save the changes, or type revert and press Enter to abort.
3.
Section 5.15.4

Viewing a List of Active Leases

RUGGEDCOM ROX II can generate a list of active leases. The list includes the start and end times, hardware
Ethernet address, and client host name for each lease.
To view a list of active leases, do the following:
services dhcpserver show-active-leases
If certificates have been configured, a table or list similar to the following example appears:
ruggedcom# services dhcpserver show-active-leases
dhcpActionResult
lease 192.168.0.9 {
starts 2 2012/11/13 20:35:47;
ends 2 2012/11/13 20:45:47;
hardware Ethernet 00:01:c0:0c:8b:a4;
client-hostname "ape2-PC";
}
lease 192.168.0.11 {
starts 2 2012/11/13 20:38:37;
ends 2 2012/11/13 20:48:37;
238
Options".
Enabling/Disabling the DHCP Relay Support
RUGGEDCOM ROX II
CLI User Guide