![FoxGate S6424-S2C2 series Скачать руководство пользователя страница 106](http://html1.mh-extra.com/html/foxgate/s6424-s2c2-series/s6424-s2c2-series_configuration-manual_2325481106.webp)
DHCP Configuration
106
addresses will be occupied by the DHCP clients permanently.
Dynamic assignment. The DHCP server assigns IP addresses to DHCP clients for
predetermined period of time. In this case, a DHCP client must apply for an IP address at the
expiration of the period. This policy applies to most clients.
15.2.2 Obtaining IP Addresses Dynamically
Interaction between a DHCP client and a DHCP server is as shown in Picture 1-2.
Figure 15-2 Interaction between a DHCP client and a DHCP server
There are three different modes for DHCP client to obtain IP address in different stage:
(1) Initial login for DHCP client
There are four stages for the initial login of DHCP client:
Discover. In this phase, the DHCP client tries to find a DHCP server by broadcasting a
DHCP-DISCOVER packet.
Offer. In this phase, the DHCP server offers an IP address. Each DHCP server that
receives the DHCP-DISCOVER packet chooses an unassigned IP address from the address
pool based on the IP address assignment policy and then broadcasts a DHCP-OFFER packet
to the DHCP client.
Select: In this phase, the DHCP client selects an IP address. If more than one DHCP
server sends DHCP-OFFER packets to the DHCP client, the DHCP client only accepts the
DHCP-OFFER packet that first arrives, and then broadcasts a DHCP-REQUEST packet
containing the assigned IP address carried in the DHCP-OFFER packet.
Acknowledge: Upon receiving the DHCP-REQUEST packet, the DHCP server returns a
DHCP-ACK packet to the DHCP client to confirm the assignment of the IP address to the
client. When the client receives the DHCP-ACK packet, it broadcasts an ARP packet with the