Showing results for 
Search instead for 
Did you mean: 

alternate to subinterface


i understand that you cant create vlan subinterface on 3750 or 3550

switch(config)#int gi1/0/52.100


% Invalid input detected at '^' marker.


Is there any alternative to create the above (by upgrading to latest ios?). basically i have a trunk port with SVI interfaces but i would like to spilit the trunk into sub interfaces and have it on its own vlan AND have the layer 3 ip for some  (like below)

switch(config)#int gi1/0/52.100

switch(config-if)# switch access vlan 100

switch(config)#int gi1/0/52.200

switch(config-if)# switch access vlan 200

switch(config)#int gi1/0/52.300

switch(config-if)# no switchport

switch(config-if)# ip address

int vlan 100

ip address

int vlan 200

ip address

is the above possible ?


Everyone's tags (2)
Rising star

alternate to subinterface


What is your purpose for that? What do you want to reach?

For such thing you need router in order to create subinterfaces.

Hope it will help

Hope it will help. Best regards, Abzal

alternate to subinterface

i would like to spilit my vlans for troubleshooting. for instance i can just shutdown just 1 vlan instead of shutting down the entire trunk port ?


alternate to subinterface

You can shut down a vlan from vlan config mode without going through this. I've never done it, but it sounds like this is what you're wanting.

DR_Switch(config)#vlan 282


VLAN configuration commands:

  are           Maximum number of All Route Explorer hops for this VLAN (or

                zero if none specified)

  backupcrf     Backup CRF mode of the VLAN

  bridge        Bridging characteristics of the VLAN

  exit          Apply changes, bump revision number, and exit mode

  media         Media type of the VLAN

  mtu           VLAN Maximum Transmission Unit

  name          Ascii name of the VLAN

  no            Negate a command or set its defaults

  parent        ID number of the Parent VLAN of FDDI or Token Ring type VLANs

  private-vlan  Configure a private VLAN

  remote-span   Configure as Remote SPAN VLAN

  ring          Ring number of FDDI or Token Ring type VLANs

  said          IEEE 802.10 SAID

  shutdown      Shutdown VLAN switching

  state         Operational state of the VLAN



HTH, John *** Please rate all useful posts ***

alternate to subinterface

Unfortunately you cannot do that on a switch.  Instead, you have to run a trunk and a bunch of SVIs, as you have done.

Unfortunately, if you are running any routing protocols through the trunk, and the trunk link fails, then the re-convergence is slower because it has to rely on dead times rather than detecting link-down.

Kevin Dorrell



Re: alternate to subinterface

say if i introduce to bring in a router and do

on router:

int fa0/0.20

encapsulation dot1q 20

ip address

no shut

int fa0/0.30
encapsulation dot1q 30
ip address
no shut

on the switch:

vlan database
vlan 20 name 20

vlan 30 name 30

int vlan 20
ip address
no shut
int vlan 30
ip address
no shut

I know the above will work for L2 vlans but for Layer 3 (without any vlans will the below config do ?)

int fa0/0.40

ip address
no shut

int fa0/0.50

ip address
no shut

on switch side (different switch to the one above)

int fa0/1

ip add

no shut

int fa0/2

ip add

no shut

Basically my question is if i replace the l3 switch with a router can i use one port for L2 sub interface and another port for L3 sub interface as above ?

if so how do i create a layer 3 sub interface ?


CreatePlease to create content
Content for Community-Ad
July's Community Spotlight Awards