DHCP options

When booting using the Dynamic Host Configuration Protocol (DHCP), a standard negotiation according to RFC 2131 is performed, i.e. the IP-STB sends a DHCP Discover, the DHCP server answers with a DHCP Offer, the IP-STB sends a DHCP Request and the DHCP server finishes the negotiation by sending a DHCP Ack. The boot replies sent from the DHCP server contains the necessary information in order for the IP-STB to use the network.

In addition to the standard parameters (IP, Netmask, Gateway etc.), KreaTV has defined specific configuration parameters that can control the entire boot behavior. Previously, KreaTV used some of the site-specific options 128-254 for these parameters. However, IETF/IANA has moved the site-specific options up to 224-254. Hence, nowadays KreaTV uses the Vendor Specific Information (option-43) with the "encapsulated vendor-specific options" format described in RFC 2132. The Vendor Class Identifier (option-60) and/or the User Class Information (option-77) should be used by the DHCP server to identify a KreaTV IP-STB and send the correct parameters in the Vendor Specific Information option accordingly.

The following special DHCP options are used by all Motorola VIP STB:s:

See also the DHCP server configuration example.

DHCP Option Name Description Values
next-server TFTP Server.

This option reflects the siaddr member in the boot reply header specified in RFC 2131.

Type: ip-adress
filename This option reflects the file member in the boot reply header specified in RFC 2131. Max length is 128 bytes. Can be one of the following:

1. TFTP Kernetl Filename and Path

2. Sets the multicast address and port for SAP (Session Announcement Protocol). Must be on the following format:
"SAP/X/224.2.127.254:9875"
where X is the number of maximum allowed open connections.

1. Type: string

1. Default Value: default_kernel

2. Type: string

2. Default Value: 224.2.127.254:9875

option-16 Swap Server Sets the server address used when booting with an NFS-mounted root file system. If this parameter is not sent, the next-server ip-address is used as the NFS server address. Note: A special kernel with NFS support is required.

Type: ip-address

option-17 Root Path Sets the path to the root file system when booting with NFS. Note: A special kernel with NFS support is required.

Type: String