5.1.3 Relay setting details
The following table describes the settings that enable the DHCP and BOOTP relay agents to forward DHCP and BOOTP packets.
|
Packet header field |
Condition for setting |
Required setting when the condition is met |
|
|---|---|---|---|
|
From client to server |
From server to client |
||
|
Relay agent address in the DHCP or BOOTP header |
The destination address in the IP header is 0.0.0.0 when the relay agent receives the original packet. |
|
- |
|
Broadcast flag in the DHCP or BOOTP header |
The flag is 1. |
- |
Set the destination IP address to restricted broadcast*. |
|
When 0 is set |
- |
Set the client IP address as the destination IP address. Set the client hardware address as the destination MAC address. |
|
|
BOOTP request hops in the DHCP or BOOTP header |
A DHCP or BOOTP request packet is forwarded to the DHCP or BOOTP server. |
Increase the number of hops by one. |
- |
|
Source address in the IP header |
A DHCP or BOOTP request packet is forwarded to the DHCP or BOOTP server. |
Replace the existing address with the IP address of the sending interface. |
- |
|
A DHCP or BOOTP reply packet is forwarded to a client. |
- |
Replace the existing address with the IP address of the sending interface. |
|
|
Destination address in the IP header |
The original address is a restricted broadcast address#. |
Replace the existing address with the helper address. |
- |
Legend:-: Not applicable
- #
-
IP broadcast address 255.255.255.255 or 0.0.0.0