How to enable DHCP snooping and setting Option 82 remote-id information based on TR-101 syntax. Follow

What is DHCP Relay option 82

DHCP Relay Option 82 provides a mechanism for DHCP server to assign IP address based on the location where the client device is in the network, the information about the location of the client can be sent along with the DHCP request to the server. Switch acts as a DHCP relay agent intercepting the DHCP requests, appends the circuit ID and remote ID in the option 82 field and forwards the request message to DHCP server.

Support models

ECS4100 series, ECS4120 series, ECS4530 series.

Topology

Step1. Set hostname and Enable DHCP snooping and option 82 on global mode.

Console#configure

Console(config)#hostname TStest
Console(config)#ip dhcp snooping
Console(config)#ip dhcp snooping vlan 1
Console(config)#ip dhcp snooping information option

Step2. Setting Option 82 remote-id information based on TR-101 syntax.

• The interface type of tr101 format only can be set via CLI in the current version.
• Default interface type of tr101 format is eth.

2.1) Console(config)#ip dhcp snooping information option remote-id tr101 node-identifier sysname

2.2) Console(config)#ip dhcp snooping information option remote-id tr101 node-identifier ip

Step3. Setting DHCP snooping trust port.

Console#configure
Console(config)#interface ethernet 1/7
Console(config-if)#ip dhcp snooping trust

Step4. Checking the status of DHCP snooping.

Step5. Verifying if the DHCP option82 works well 

The client sends the DHCP Discover packet and captures it at DHCP Server. The packet captured show string info in remote-id. DHCP_Server will compare and assign the IP address according to the configuration.