3Com 10014299 Configure slave IP address of an interface, Delete slave IP address of an interface

IP Address Overview 321

When configuring the master IP address for an interface, note:

■An interface can only have one master IP address.

■When deleting the IP address of the interface, if no IP address and mask is specified, all the IP addresses (including all slave IP addresses) will be deleted from the interface.

■One router can be configured with up to 200 IP addresses at most.

■Only the Loopback interface can be configured with 32-bit mask and other interfaces can only be configured with 30-bit mask at most.

2Configure slave IP address of an interface

Besides the master IP address, at most 4 slave IP addresses can be configured on an interface. The purpose of assigning slave IP addresses is to have the same interface located in different sub-nets, so as to create network routes with the same interface as the output port, and set up connection via the same interface to multiple sub-nets.

Table 353 Configure slave IP address of an interface

Operation	Command
Configure slave IP address of an interface	ip address ip-address { mask
	mask-length } sub
Delete slave IP address of an interface	undo ip address ip-address{	mask
	mask-length } [ sub ]

By default, the interface has no slave IP address.

When configuring slave IP addresses for an interface, please note:

■Slave IP addresses cannot be on the same network segment with each other and they cannot be on the same network segment with the master IP address. Otherwise, the system will prompt:

■IP address configured now conflicts with others.

■If the interface is not configured with the master IP address, the first configured IP address will become the master IP address automatically.

■When there are slave IP addresses on the interface, the master IP address cannot be deleted. Otherwise, the system will prompt:

Must delete secondary before deleting primary.

3Set negotiable attribute of an IP address for an interface

When an interface is encapsulated with PPP, but not configured with IP address while the peer has been configured with IP address, the user can configure negotiable attribute of IP address on the interface on the local router. (To configure ip address ppp-negotiatecommand on the local router, and to configure remote address on the peer router) In this case, the local router can accept the IP address originated from PPP negotiation and allocated by the peer router. Such configuration is mainly used to obtain IP address allocated by ISP when accessing the Internet via ISP.