DHCP, DHCP Relay, DHCP snooping
I. DHCP
1. Example diagram
two。 Configuration steps (see figure)
(1)。 Configure the IP address of the interface.
(2)。 Enable the DHCP service.
(3)。 Configure IP addresses that do not participate in automatic assignment.
(4)。 Configure DHCP address pool 0 and assign IP addresses in a dynamic binding manner.
3. Results (PC_1, PC_2)
II. DHCP relay. The DHCP server is on the router, while there are three VLAN on the SWA, which belong to three different network segments. The request message of the DHCP is broadcast, so the relay must be set up on the SWA before it can be transmitted to the router.
1. As shown in the picture
two。 Configuration step
(1)。 Configure the router
(1-1). Enable the DHCP service
(1-2). Configure DHCP address pool 1 to assign addresses to clients from within the 192.168.1.0 Universe 24 network segment.
Configure DHCP address pool 2 to assign addresses to clients from within the 192.168.20.0 tap 24 network segment.
Configure DHCP address pool 3 to assign addresses to clients from within the 192.168.30.0swap 24 network segment.
Configure a static route to the 192.168.0.0ax 16 segment
(2)。 Configure the SWA switch
(2-1). Establish vlan and configure the IP address of each interface
(2-2). Configure DHCP trunking
Enable the DHCP service
Configure VLAN interface 10 to operate in DHCP trunk mode
Configure the address of the DHCP server
Configure VLAN interface 20 to operate in DHCP trunk mode
Configure VLAN interface 30 to operate in DHCP trunk mode.
3. Results (PC_1, PC_2)
Three. DHCP Snooping. The DHCP server is on the router, while there are three VLAN on the SWA, which belong to three different network segments. The request message of the DHCP is broadcast, so the relay must be set up on the SWA before it can be transmitted to the router. Pseudo DHCP Server has been configured to publish the address pool of 172.22.1.1-99 and the gateway 172.22.1.254 DNS 9.9.9
1. As shown in the picture
2.2. Configuration step
(1)。 Configure the router.
(1-1). Enable the DHCP service.
(1-2). Configure DHCP address pool 1 to assign addresses to clients from within the 192.168.1.0 Universe 24 network segment
Configure DHCP address pool 2 to assign addresses to clients from within the 192.168.20.0 tap 24 network segment.
Configure DHCP address pool 3 to assign addresses to clients from within the 192.168.30.0swap 24 network segment.
(1-3). Configure a static route to the 192.168.0.0ax 16 segment
(2)。 Configure the SWA switch.
(2-1). Establish vlan and configure the IP address of each interface
(2-2). Configure DHCP trunking
Enable the DHCP service.
Configure VLAN interface 10 to operate in DHCP trunk mode
Configure the address of the DHCP server
Configure VLAN interface 20 to operate in DHCP trunk mode.
Configure VLAN interface 30 to operate in DHCP trunk mode.
(3)。 Configure DHCP Snooping (SWB switch)
(3-1). Configure DHCP Snooping
Enable DHCP Snooping featur
Set the GigabitEthernet1/0/21 port as a trusted port
3. Results (PC_1, PC_2)
