NEC ZA-SA3500G, Руководство по эксплуатации функций

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| Function Specification 99
3.6.10. DHCP Client
[Operating interface]
WAN interface
[Basic specifications]

It is based on RFC2131 and RFC2132. Moreover, it supports the DHCP relay function.

Supported messages are as follows.
Packet Direction DHCP Message
Send DISCOVER, REQUEST, RELEASE, DECLINE
Receive OFFER, ACK

When the ACK message from DHCP server is received, ARP checks duplication of the distribution IP address.

The DHCP RELEASE message is sent when IP address distributed from the DHCP server overlaps with the LAN
interface IP address of this product. Afterwards, the DHCP sequence resumes.
[DHCP message transmission timing]
Transmission timing of RENEWING/REBINDING is as follows.
Extension Request
Timing Destination No. of
Transmissions Description
RENEWING
Lease time×0.5 unicast 1 T1
unicast (resend) * If the remaining time until T2 is at least 60 seconds, it is
sent by half.
REBINDING
Lease time×0.875 broadcast 1 T2
broadcast
(resend) * If the remaining time until lease time is at least 60
seconds, it is sent by half.
Transmission timing of DISCOVER message is as follows.
DISCOVER Transmission
Timing Description
At DHCP startup When there is no response 3 seconds after transmitting, it will be retransmitted.
Resending is repeated twice, and if there is still no response after 20 seconds, the
transmission will be redone.
(If there is no response, send in 3 seconds -> 3 seconds -> 23 seconds -> 3 seconds
-> 3 seconds ...)
When lease time expires As with DHCP startup, when there is no response 3 seconds after transmitting, it will
be retransmitted.
Resending is repeated twice, and if there is still no response after 20 seconds, the
transmission will be redone.
(If there is no response, send in 3 seconds -> 3 seconds -> 23 seconds -> 3 seconds
-> 3 seconds ...)