The Catalyst 3560 switch support these types of layer 3 interfaces:
SVIs :You should configure SVIs for any VLANs for witch you want to route traffic.SVIs are created when you enter a VLANID following the inerface vlan gloabl configuration command.
To delete an SVI, use the no interface vlan global configuration command.
Router ports: routed ports are physical ports configuration to be in layer 3 mode by using the no
switchport interface configuration command.
Layer 3 Etherchannel ports:Etherchannel interface made up of routed ports.
A Layer 3 switch can have an IP address assigned to each router port and SVI.
There is no defined limit th the number fo SVIs and routed prots that can be configured in a switch.
However, the interrelationship between the number of SVIs and routed ports and number of other
features being configuratiod might have an impact on CPU usage because of hardware limitations.
If the switch is using maximum hardware resources. attempts to create a routed port or SVI have
these results:
If you try to create a new routed port, the switch generates a message that there are not enough
resources to convert the interface to a routed port, and the interface remains as a switchport.
If you try to create an extended-range VLAN , an error message if generated, and the extended-range
VLAN is rejected.
If the switch is notified by VLAN Trunking protocol(VTP) of a new VLAN, it sends a message that there are not enough hardware resources available and shuts down the VLAN.The output of the show vlan user EXEC command show the VLAN in a suspended state.
If the switch attempts to boot up with a configuration that has more vlans and routed ports than
hardware can support, the vlans are created, but the routed ports are shutdown , and the switch
sends a message that this was due to insufficient hareware resources.
All layer 3 interface require an IP address to route traffic.This procedure shows how to configure
an interface as a layer 3 interface and how to assign an ip address to an interface.
If the physical port is in layer 3 mode (the default), you must enter the
no switchport interface
configuration command to put the interface into layer 3 mode.Entering a no switchport command
disables and then re-enable the interface, which might generate message on the device to which
the interface is connected.
Beginning in privilege EXEC mode, follow these steps to configure a Layer 3 interface.
interface {{fastethernet | gigabitternet } interface-id} | {vlan vlan-di}| {port-channel port-channel-number}
Enter interface configuration mode, and enter the interface to be configuratied as a layer3 inteface.
no switchport
for physical ports only , enter layer 3 mode.
show interface
show ip interface
show runing-config interface
The remove an ip address for a interface , use the no ip address interface configuration command.
This exapmle shows how to configure a port as a routed port and to assign it an IP address.
switch#configuration terminal
switch(config)#interface gigabitethernet 0/1
switch(config-if)#no switchport
switch(config-if)#ip address 1.1.1.1 255.255.255.0
switch(config-if)#no shutdown