First question here. I am very new to Cisco systems - about 3 days worth of knowledge.

I am trying to migrate our configuration from our old router to our new router. Our new router is a Cisco 2900, and our old router is a 877m.

Here is a clip from our old router's running-config:

interface Vlan1
 description --- Office bound to fa0
 ip address
 ip nat inside
 ip virtual-reassembly

My understanding is that these vlans exist on this configuration simply as an alias to the "real" interfaces, to make it easier to swap them around if need be. I have successfully replicated all of the configuration into the new router except the creation of these vlans and the migration of the interface config to them.

So I've been trying to figure out how to create these vlans. I've been told I can create them with the vlan database command from admin mode. However this gives me a warning about this method being deprecated:

host#vlan database
% Warning: It is recommended to configure VLAN from config mode,
  as VLAN database mode is being deprecated. Please consult user
  documentation for configuring VTP/VLAN in config mode.


so then I tried to find out what commands to use in conf mode, and all I could find was posts like these, saying i simply use vlan 1: https://supportforums.cisco.com/discussion/9819021/vlan-database-deprecated But this does not work for me:

host(config)#vlan 1
% Invalid input detected at '^' marker.

host(config)#vlan ?
  accounting  VLAN accounting configuration
  ifdescr     VLAN subinterface ifDescr


Is there some module that I still need to install? Some other setting I need to enable? Or should I continue using vlan database even though it's deprecated?

  • OK, you have a real router, but the link you have to a post is for a 2900 series switch. Do You have a switch module in your router? What is your network design? What is the existing router configuration? You need to give us more information.
    – Ron Maupin
    Nov 16, 2015 at 5:45
  • Yes I believe the old router has a catalyst module... So definitely possible our new router will not support configuring vlans this way.
    – Nacht
    Nov 16, 2015 at 5:56
  • You need to edit you question to include everything that you have. A 2900 router will only have three ethernet ports unless you have other modules, too. What are they? We can't help you unless you give us everything.
    – Ron Maupin
    Nov 16, 2015 at 6:00
  • I'm suspicious that you actually have a switch and not a router. Can you type "show version" on the device and post the output?
    – Ron Trunk
    Nov 16, 2015 at 13:34
  • Ron & Ron, you may want to check the chat room as the OP started asking about this there. I also assumed it was a switch at first, then found out it was a router, and finally a 2900 ISR just before I had to leave for the night.
    – YLearn
    Nov 16, 2015 at 15:44

1 Answer 1


It seems like there is some confusion going on here. While Cisco typically appears to try to avoid re-using product line numbering, there are exceptions (and possibly more recently). The 2900 ISR router series is one of them. It overlaps with an older switching product line, the Catalyst 2900 series.

To muddy the waters more, your current 800 ISR series router is a router with a switch built in, allowing it to support some switch commands in addition to the normal router commands. Specifically, IIRC (been a while since I configured one of these, maybe I can find one to play with later today) all the "LAN" ports are actually part of this switch and as such cannot be configured like a router interface.

The whole ISR series of routers is designed to provide functionality of multiple platforms into one integrated platform. As I understand the 2900 ISR platform, you will only have certain commands/features available if the associated hardware is installed and/or licensed. Specifically, to add VLANs like you are attempting, you would need to have one of the Gigabit EtherSwitch modules.

My best guess is that you don't have one of these modules installed in the router and you only really have router interfaces available. These will need to be configured differently than the configuration in your old router.

To confirm, you would have to provide more details in your question about the specifics of the hardware installed in your router.

  • I ended up just not using vlans in the new router. Thanks for the help
    – Nacht
    Nov 17, 2015 at 10:29

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