Configure DHCP address pools on S series switch
When functioning as DHCP servers, S series switches (except S1700 switches) support the interface and global address pool configurations.
- Interface address pool: The network segment to which the primary IP address of an interface belongs is an interface address pool. The DHCP server allocates IP addresses only on this network segment to clients connected to the interface.
- Global address pool:
1. If a switch functioning as the DHCP server is on the same network segment as clients (that is, no DHCP relay agent is configured), the switch allocates IP addresses on the same network segment as the primary IP address of the interface connected to clients. If no primary IP address is configured for the interface or no address pool is on the same network segment as the interface's primary IP address, the clients cannot obtain IP addresses.
2. If a switch functioning as the DHCP server is on a different network segment from a DHCP client (that is, a DHCP relay agent is configured), the DHCP server parses the IP address (primary IP address of the first DHCP relay agent's interface) specified in the giaddr field of a DHCP Request packet, and allocates an IP address on the same network segment as the parsed IP address from an address pool to the client. If no address pool matches the parsed IP addresses, the client cannot obtain an IP address.
When configuring address pools, follow the preceding rules to ensure that clients can obtain IP addresses.