1841 ISR subinterface with VLAN Tagged > 1005

[jj27]

Greetings,

I am trying to roll out a new internet router.  The problem I am faced with is the LEC only supports VLAN 1227 and greater, specifically they are assigning me VLAN 2528.

I am able to create the sub-interface and setup dot1q encapsulation for VLAN 2528, but the vlan database does not have the ability to add VLAN 2528 to it so I am unable to get layer 2 up and going, thus preventing me from getting the implementation done.

Are there any workarounds for this, or any other suggestions you may have to accomplish my goal?

Thanks.

[paolo bevilacqua]

Which exact IOS are using? You need greater than 12.4(15)T for this to work.

http://www.cisco.com/en/US/docs/ios/12_4t/12_4t15/ht_xvlan.html

[jj27]

Thanks for the link.  I had found that before, but didn't notice the (T) release requirement.

It is currently running: c1841-ipbasek9-mz.124-25d.bin

Do I need to download a T release IOS then?

[paolo bevilacqua]

Yes, you do.

Please remember to rate useful posts clicking on the stars below.

[jj27]

Thanks again for the assistance, but it does not work.  I upgraded to c1841-ipbasek9-mz.124-24.T4. I believe that article assumes that my router has a switch module in it, which it does not, so the spanning-tree and vlan commands will not work.

[paolo bevilacqua]

Yes the article has examples in which a switch module is used, but the extended range should be applicable alos if there is none.

However not that I think about, when you are simply using a subinterface with tagging, no vlan needs to be created. You may as well delete the vlan database and start again.

Then you can try for example, 15.0(1)M4 and if still troubles, resort to the TAC for clarification.

[jj27]

It has always been my assumption in the past where if I wanted to turn on DOT1Q encapsulation on a subinterface for a vlan, that vlan also had to exist in the vlan database.  I've had past experiences where creating the subinterface and tagging the traffic did not work until I edited the VLAN database to create the vlan and enable it.

My idea now is to use a layer 3 switch to plug the provider's device to with a trunk link, then plug my router in as an access port on the VLAN and give it a whirl.  That should work, no?

[paolo bevilacqua]

On which interface are you doing this ?

I have hundreds of routers with subinterface (admittedly all low number tagged), an no vlan database was ever necessary or involved.

[jj27]

Interface FastEthernet0/1 - we just tried another method to get it working and still did not have connectivity to the provider so I think it might be something on their back end, even though they said it wasn't. This isn't a tough configuration at all, so I don't know why we're having so many problems.

[paolo bevilacqua]

Yes I believe this is not your router fault. You can send "show interface" if you want.

[Tihomir Yosifov]

Hi, I have same topology as yours. You definitely do NOT need to define a Vlan in your vlan database. Your config should be similar to this:

interface FastEthernet 0/1

no ip address

no shutdown

interface FastEthernet 0/1.2528

encapsulation dot1Q 2528

ip address x.x.x.x y.y.y.y

Make sure you have a default route:

ip route 0.0.0.0 0.0.0.0 fa 0/1.2528 z.z.z.z

where z.z.z.z is your gateway (the ISP side ip address)

try testing by doing ping to the gateway IP address with source FastEthernet 0/1.2528

ping z.z.z.z source FastEthernet 0/1.2528

Regards,

Tihomir Yosifov

[jj27]

Thanks for verification also.  I thought our configuration was right, just wanted to run it by others to see if they had a similar issue.