ip interface define (3500/9000 Layer 3) 403
ip interface define
✓ 3500
✓ 9000
9400
3900
9300
(3500/9000 Layer 3)
For CoreBuilder 9000: Applies to Layer 3 switching modules only.
Defines an IP interface.
Valid Minimum Abbreviation
ip i def
Important Considerations
■When you define an IP interface, you m ust decide whether you want
the interface to use router port-based routing or VLAN-based rou ting.
■Router port-based routing directs the sys tem to attempt to rout e
the frame before it attempts to bridge the frame.
When you set up a router port-based IP interface, the system
automatically creates a virtual LAN (VLAN) for the interface. The
system assigns the next available VLAN index number to this VLAN.
■VLAN-based routing directs the system to attempt to bridge th e
frame before it attempts to route the frame.
When you set up a VLAN-based IP interface, you must first define a
VLAN and select IP as a protocol supported by the VLAN, as
described in Chapter 14.
If you define a router port, you do not hav e to define the VLAN first; the
corresponding single-port VLAN is automa tically defined.
■Port-based routing uses allClosed mode; VLAN-based routing uses
either allClosed or allOpen mode. If you attem pt to set up a router
port-based IP interface in allOpen mode, the system notifies you with
a message that it will change the VLAN mode to allClosed and
recreate the default VLAN, clearing your existing VLANs in the process.
Then the system prompts you to continue. (See the port-based router
example at the end of this command description.)
■You cannot define a port-based IP interface on a port that is already a
member of a VLAN-based IP interface. To change from one type of
interface to another, you must redefine all IP interfaces and VLANs
that are associated with that port.
CAUTION:Using different routing models (port-based or VLAN-based) in
the same network without careful planning can adversely affect your
network operations. Be sure that you understand the potential effects of
router port-based and VLAN-based routing on your network. See the
Implementation Guide for the CoreBuilder 3500 and for the
CoreBuilder 9000 for detailed information about IP interfaces and VLANs.