Create different IP pool for every VLAN. The device in different VLAN can get the IP
address in different subnet.
When receiving a DHCP-DISCOVER packet from the client, the switch judges the VLAN
which the ingress port belong to, and chooses the IP in the same subnet with the VLAN
interface to assign to the client.
With a DHCP Relay running between the client and the server, when receiving a
DHCP-DISCOVER packet transmitting from the Relay, the switch will choose the IP from the
IP pool in the same subnet with the Relay’s IP to assign to the client. If the IP pool is not
configured on the switch or the configured IP pool doesn’t match the Relay’s network
segment, the client may not get network parameters successfully.
The switch can detect the IP address automatically before assigning it to avoid conflict.
IP Detection
To avoid IP conflict, the switch will detect the IP address to be assigned in LAN through Ping
test.
The DHCP server will send the Ping test packet with the destination IP being the IP address to
be assigned. If the server receives the Reply packet from the destination host in the ping time,
it means that the IP address has been used, and the server will choose another IP as
destination IP to test again. The server will assign the IP address if the server not receives the
Reply packet in the Ping time.
Policy of IP Assignment
The switch chooses the IP assigned to clients based on the rules shown as follows.
1)
First, the server will choose the IP which has been bound to the client manually.
2)
Then, the server will assign the IP which has been assigned to the client once.
3)
For the next, the server will assign the IP which is specified in the DHCP-DISCOVER packet
from the client.
4)
At last, the server will choose the first IP from the IP pool which has not been assigned.
Tips for Configure DHCP Server Function on T3700G-52TQ
1)
Configure the Excluded IP address which cannot be assigned by the switch, e.g. web
server’s IP, broadcast IP of subnet and gateway’s IP.
2)
Specify IP address for specific clients, and then the switch will supply these IP address to
them only for ever.
3)
Configure the IP pool in which the IP address can be assigned to the clients.
The DHCP Server, allowing the clients in all VLANs to get the IP address from the server
automatically, is implemented on the
DHCP Server
,
Pool Setting
,
DHCP Options Set
,
Binding
Table
and
Packet
Statistics
pages.
10.4.1
DHCP Server
This page allows you to enable the DHCP Server function, configure the Excluded IP Address
which cannot be assigned by the switch in every network.
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