To configure a DHCP server process detailed

3550 Configuration of DHCP, the network has many discussions, but most of the existence of errors and omissions, according to the configuration of the online introduction of "IP helper-address DHCP server address", the project found that the client can not obtain the IP address from the DHCP server, I also recently configured 3550 as a relay agent for the DHCP server, initially puzzled for a long time, and then find information on the Internet and in the forum to seek help, and finally in the project test through, in order to avoid everyone in the project encountered in this kind of situation left turn right, special will be the configuration process written out, for everyone as a reference.

Network environment: A 3550EMI switch, divided into three vlan,vlan2 for the server network, named Server,ip address segment is 192.168.2.0, Subnet mask: 255.255.255.0, Gateway: 192.168.2.1, The domain server is Windows Advance Server, concurrently as a DHCP server, DNS server, IP address 192.168.2.10,VLAN3 is the client 1 network, IP address segment is 192.168.3.0, Subnet mask : 255.255.255.0, Gateway: 192.168.3.1 named WORK01,VLAN4 for Client 2 network, named Work02,ip address segment is 192.168.4.0, subnet mask: 255.255.255.0, Gateway : 192.168.4.1 3550 Ports 1-8 to VLAN 2, Port 9-16 is divided into VLAN 3, Port 17-24 is divided into VLAN 4.

The configuration commands and steps are as follows:

First step: Create VLAN:

Step two: Enable the DHCP Relay Agent:

/* Critical step, if the following two commands are missing, use "IP helper-address DHCP server address" in the VLAN to specify the DHCP server, and the client still cannot obtain the IP address.

Step three: Set VLAN IP address:

/* Note: Because the port is not configured to vlan2,3,4 at this time, so the VLAN will be down, the port will be assigned to each VLAN, the VLAN will rise * * *

Fourth step: Set Port global parameters

Step Fifth: Add the port to the vlan2,3,4

/* Add Port 1-8 to the VLAN 2*/

/* Add Port 9-16 to the VLAN 3*/

/* Add Port 17-24 to the VLAN 4*/

* * After this step, the VLAN will rise * * *

Step Sixth: Set the DHCP server address in VLAN3 and 4

No DHCP server address must be specified in/*vlan 2 * *

Step Seventh: Enable routing

/* routing enabled, each VLAN host can access each other, if you need to further control access rights, you need to apply to the access control list * *

Step eighth: End and save the configuration

The above authors tested and approved