Siemens RUGGEDCOM ROX II, User Manual

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Chapter 7
IP Address Assignment
RUGGEDCOM ROX II
CLI User Guide
226 Managing DHCP Client Configuration Options
• For IPv6
services » dhcpserver6 » options
3. Configure the following parameter(s) as required:
IMPORTANT!
For IPv4 only:
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
(negative acknowledgment or not acknowledged) message to disallow the lease. Enabling Option
82 disables the NAK message so 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.
Option 82 support should only be enabled If the DHCP server and clients are on the same subnet.
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.
DHCP relay support can also be enabled on individual subnets. For more information, refer to
Section 7.3.8.3, “Configuring Subnet Options” .
Parameter Description
unknown-client { unknown-client } Synopsis: { allow, deny, ignore }
The action to take for previously unregistered clients
authorize-server Enables/disables the server's authorization on this client. If enabled, the server will send
deny messages to the client that is trying to renew the lease, which the server knows the
client shouldn't have.
option82 Enables/disables the NAK of option 82 clients for this subnet.
4. [Optional] Configure additional client configuration options. For more information, refer to Section 7.3.5.1,
“Configuring Standard DHCP Client Configuration Options (IPv4)” or Section 7.3.5.2, “Configuring Standard
DHCP Client Configuration Options (IPv6)” .
5. Type commit and press Enter to save the changes, or type revert and press Enter to abort.
Section 7.3.5
Managing DHCP Client Configuration Options
Standard and custom options can be configured globally at the DHCP server level, or for specific shared networks,
subnets, host groups or hosts. Options set at an individual level override options set at the global level.
CONTENTS
• Section 7.3.5.1, “Configuring Standard DHCP Client Configuration Options (IPv4)”
• Section 7.3.5.2, “Configuring Standard DHCP Client Configuration Options (IPv6)”
• Section 7.3.5.3, “Viewing a List of Custom DHCP Client Configuration Options”
• Section 7.3.5.4, “Adding a Custom DHCP Client Configuration Option”
• Section 7.3.5.5, “Deleting a Custom DHCP Client Configuration Option”