3Com MSR 50, MSR 30 manual 745

745

By default, an interface does not use DHCP for IP address acquisition.

Note that:

■If no parameter is specified, the client uses a character string comprised of the current interface name and MAC address as its ID for address acquisition.

■The DHCP client sends a DHCP-RELEASE message for releasing the IP address obtained via DHCP, if the interface of the client is down, the message cannot be sent.

■For a sub interface that obtained an IP address via DHCP, using the shutdown command on its primary interface does not make the DHCP client send a DHCP-RELEASE message for releasing the sub interface’s IP address.

Example # Configure interface Ethernet 1/0 to use DHCP for IP address acquisition.

<Sysname> system-view

[Sysname] interface ethernet 1/0

[Sysname-Ethernet1/0] ip address dhcp-alloc

n ■ The DHCP snooping is supported only on the Layer 2 Ethernet interface.

■DHCP Snooping supports no link aggregation. If a Layer 2 Ethernet interface is added into an aggregation group, DHCP Snooping configuration on it will not take effect. When the interface is removed from the group, DHCP Snooping can take effect.

■The DHCP snooping enabled device does not work if it is between the DHCP relay agent and DHCP server, and it can work when it is between the DHCP client and relay agent or between the DHCP client and server.

■The DHCP Snooping enabled device cannot be a DHCP server or DHCP relay agent.

■You are not recommended to enable the DHCP client, BOOTP client, and DHCP Snooping on the same device. Otherwise, DHCP Snooping entries may fail to be generated, or the BOOTP client/DHCP client may fail to obtain an IP address.

n Only the H3C MSR series routers installed with the 16-port or 24-port switching card support DHCP snooping.