User's Manual
Table Of Contents
- 1. INTRODUCTION
 - 2. INSTALLATION
 - 3. SWITCH MANAGEMENT
 - 4. WEB CONFIGURATION
- 4.1 Main Web page
 - 4.2 System
- 4.2.1 Management
- 4.2.1.1 System Information
 - 4.2.1.2 IP Configuration
 - 4.2.1.3 IP Status
 - 4.2.1.4 Users Configuration
 - 4.2.1.5 Privilege Levels
 - 4.2.1.6 NTP Configuration
 - 4.2.1.6.1 System Time Correction Manually
 - 4.2.1.7 Time Configuration
 - 4.2.1.8 UPnP
 - 4.2.1.9 DHCP Relay
 - 4.2.1.10 DHCP Relay Statistics
 - 4.2.1.11 CPU Load
 - 4.2.1.12 System Log
 - 4.2.1.13 Detailed Log
 - 4.2.1.14 Remote Syslog
 - 4.2.1.15 SMTP Configuration
 - 4.2.1.16 Fault Alarm
 - 4.2.1.17 Digital Input/Output
 
 - 4.2.2 Simple Network Management Protocol
 - 4.2.3 RMON
 - 4.2.4 DHCP server
 - 4.2.5 Industrial Protocol
 - 4.2.6 Remote Management
 
 - 4.2.1 Management
 - 4.3 Switching
- 4.3.1 Port Management
 - 4.3.2 Link Aggregation
 - 4.3.3 VLAN
- 4.3.3.1 VLAN Overview
 - 4.3.3.2 IEEE 802.1Q VLAN
 - 4.3.3.3 VLAN Port Configuration
 - 4.3.3.4 VLAN Membership Status
 - 4.3.3.5 VLAN Port Status
 - 4.3.3.6 Private VLAN
 - 4.3.3.7 Port Isolation
 - 4.3.3.8 VLAN setting example:
 - 4.3.3.9 MAC-based VLAN
 - 4.3.3.10 IP Subnet-based VLAN Membership Configuration
 - 4.3.3.11 Protocol-based VLAN
 - 4.3.3.12 Protocol-based VLAN Membership
 
 - 4.3.4 Spanning Tree Protocol
 - 4.3.5 Multicast
 - 4.3.6 MLD Snooping
 - 4.3.7 MVR (Multicast VLAN Registration)
 - 4.3.8 LLDP
 - 4.3.9 MAC Address Table
 - 4.3.10 Loop Protection
 - 4.3.11 UDLD
 - 4.3.12 GVRP
 - 4.3.13 PTP
 - 4.3.14 Link OAM
 
 - 4.4 Quality of Service
 - 4.5 Security
 - 4.6 Power over Ethernet
 - 4.7 Ring
 - 4.8 ONVIF
 - 4.9 Maintenance
 
 - 5. SWITCH OPERATION
 - 6. TROUBLESHOOTING
 - APPENDIX A: Networking Connection
 - APPENDIX B : GLOSSARY
 
User’s Manual of IGS-5225 series 
101 
4.2.1.9 DHCP Relay 
Configure DHCP Relay on this page. DHCP Relay is used to forward and transfer DHCP messages between the clients and the 
server when they are not on the same subnet domain.   
The DHCP option 82 enables a DHCP relay agent to insert specific information into a DHCP request packets when forwarding 
client DHCP packets to a DHCP server and remove the specific information from a DHCP reply packets when forwarding server 
DHCP packets to a DHCP client. The DHCP server can use this information to implement IP address or other assignment 
policies. Specifically the option works by setting two sub-options:   
  Circuit ID (option 1)   
  Remote ID (option 2) 
The Circuit ID sub-option is supposed to include information specific to which circuit the request came in on.   
The Remote ID sub-option was designed to carry information relating to the remote host end of the circuit. 
The definition of Circuit ID in the switch is 4 bytes in length and the format is "vlan_id" "module_id" "port_no". The parameter of 
"vlan_id" is the first two bytes representing the VLAN ID. The parameter of "module_id" is the third byte for the module ID. The 
parameter of "port_no" is the fourth byte and it means the port number.   
The Remote ID is 6 bytes in length, and the value equals the DHCP relay agent’s MAC address. The DHCP Relay Configuration 
screen in Figure 4-2-12 appears. 
Figure 4-2-12 DHCP Relay Configuration Page Screenshot 
The page includes the following fields: 
Object  Description 
•  Relay Mode 
Indicates the DHCP relay mode operation. Possible modes are: 
  Enabled: Enable DHCP relay mode operation. When enabling DHCP relay 
mode operation, the agent forwards and transfers DHCP messages between 
the clients and the server when they are not on the same subnet domain. 
And the DHCP broadcast message won't flood for security considered.   
  Disabled: Disable DHCP relay mode operation. 
•  Relay Server 
Indicates the DHCP relay server IP address. A DHCP relay agent is used to 
forward and transfer DHCP messages between the clients and the server when 
they are not on the same subnet domain. 
•  Relay Information 
Mode 
Indicates the DHCP relay information mode option operation. Possible modes 
are:   










