Configurating Vlan on Cisco 1921

[Iddk]

Hi all,

I am trying to configure a VLAN on a cisco 1921, however the usual

"conf t

vlan 20" does not work. The CLI tells me invalid input, however when i only put "vlan" without an id number it tells me incomplete command

Does anyone know of another way to create the a vlan? is anything restricting the vlan creation on such routers?

Thanks for your help!

[Mark Malone]

Hi
is there a switching module in it , as these routers are pure l3 , from memory there was no l2 ports just l3 and had to do router on stick before when there was no switching module in it for l2 ports

[Iddk]

Hi mark,

Thanks for this quick reply!

There are no L2 ports, I only use two gigabitethernet ports (0/0 and 0/1) to connect to a switch ring and the end user. The routing function works (already tested without the creation of a VLAN).

As I am kind of new to this world I do not think there is a switching module however how can I be certain of this? (there is no EHWIC module)

Thanks for your help!

[Mark Malone]

There would be a block of extra ports and actual physical module in the 1921 , also show inventory will show you ,these are pure l3 routers thats why you cant create the vlan , they dont support it but if you had a switching module in it it would have l2 functions as well with an ipbase license i think you need minimum

https://www.cisco.com/c/en/us/products/collateral/routers/1900-series-integrated-services-routers-isr/data_sheet_c78-598389.html

from the data sheet
Integrated LAN Switching

The Cisco 1921 Integrated Services Router will support the EHWIC LAN modules when they become available in the future. The Cisco 1921 supports the existing singlewide Cisco EtherSwitch® HWIC and the doublewide HWIC-D modules, which greatly expand the capabilities of the router by integrating industry-leading Layer 2 switching.

[paul driver · Accepted solution]

Hello

You could create l3 interface for vlan 2 and trunk the switchport connecting to the rtr , but it al depends on where your perform your inter-vlan routing ( rtr or switch)

The below example shows the rtr doing it.

rtr
int gig0/0

no shut
int gig0/0.2
Description Vlan 2
encapsulation dot1q 2
ip address xxxx.xxxx

switch

conf t
vlan 2

int x/x
description link to rtr
switchport mode trunk

int x/x
description access-port
switchport host
switchport access vlan 2

res
Paul

[Iddk]

Hi paul,

Thanks for your help! it worked!

Thanks to Marc too for the help!

All the best!