3com 3031 Instruccion De Instalación
360
C
HAPTER
28: IP A
DDRESS
C
ONFIGURATION
This IP address is assigned by the opposite end. This configuration is mainly used
to obtain IP address assigned by ISP when accessing Internet via ISP.
to obtain IP address assigned by ISP when accessing Internet via ISP.
Perform the following configuration in the interface view.
1) Because PPP supports IP address negotiation, IP address negotiation of an
interface can be set only when the interface is encapsulated with PPP. When the
PPP link is down, the IP address originated from negotiation will be deleted.
interface can be set only when the interface is encapsulated with PPP. When the
PPP link is down, the IP address originated from negotiation will be deleted.
2) If the interface has original address, then after setting IP address of the interface
to negotiable, the original IP address will be deleted.
to negotiable, the original IP address will be deleted.
3) After setting IP address of an interface to negotiable, it is unnecessary to
configure IP address for the interface, as negotiation will automatically originate
an IP address.
configure IP address for the interface, as negotiation will automatically originate
an IP address.
4) After setting IP address of an interface to negotiable, if the interface is set to
negotiable again, then the IP address originated from the original negotiation will
be deleted, and the interface obtains IP address through the re-negotiation.
negotiable again, then the IP address originated from the original negotiation will
be deleted, and the interface obtains IP address through the re-negotiation.
5) The interface will have no address after the negotiation address is deleted.
6) The address of Loopback interface can be borrowed by other interfaces, but it
cannot borrow the addresses of other interfaces.
cannot borrow the addresses of other interfaces.
Configuring IP Address
Unnumbered for an
Interface
Introduction to IP Address Unnumbered
The main purpose of borrowing IP address is to save IP address resource.
If an interface has no IP address, it can neither generate any route nor forward any
packet. "IP Address Unnumbered" is used when you want to use an interface with
no IP address. In such case, an IP address will be borrowed from another interface.
If the lending interface has multiple IP addresses, then only the master one can be
borrowed. However, if the lending interface has no IP address, then the IP address
of the borrowing interface is 0.0.0.0. This function is implemented through the
command
packet. "IP Address Unnumbered" is used when you want to use an interface with
no IP address. In such case, an IP address will be borrowed from another interface.
If the lending interface has multiple IP addresses, then only the master one can be
borrowed. However, if the lending interface has no IP address, then the IP address
of the borrowing interface is 0.0.0.0. This function is implemented through the
command
ip address unnumbered
.
The following should be noted:
■
The borrower can not be an Ethernet interface.
■
The address of the lending interface cannot be a borrowing address.
■
The lending interface can lend its address to multiple interfaces.
Table 406 Setting negotiable attribute of IP address for an interface
Operation
Command
Set negotiable attribute of IP address for an
interface
interface
ip address ppp-negotiate
Cancel negotiable attribute of IP address for an
interface
interface
undo ip address ppp-negotiate
Configure to assign IP address for the peer
interface
interface
remote-address { ip-address |
pool [ pool-number ] }
pool [ pool-number ] }
Disable to assign IP address for the peer interface
undo remote-address