Solved

Cisco 2901 - Trunking Port/Vlan allowed Question

Posted on 2013-06-11
10
3,528 Views
Last Modified: 2013-07-22
Hey Guys,

I’ve got a  Cisco CISCO2901/K9 router which I’m wanting to configure the GI0/3/3 port to a trunking port and only allow vlan 1101 over the trunk.

The switchport is configured as a trunking port and is working fine. However when I use the command switchport trunk allowed vlan add 1101 it looks like it accepts it, but then doesn’t show up in the show interfaces trunk.

interface GigabitEthernet0/3/3
 description LINK_WAN
 switchport mode trunk
 no ip address


ROUTER#show interfaces trunk

Port      Mode         Encapsulation  Status        Native vlan
Gi0/0/0   on           802.1q         trunking      1
Gi0/3/3   on           802.1q         trunking      1

Port      Vlans allowed on trunk
Gi0/0/0   1-4094
Gi0/3/3   1-4094

Port      Vlans allowed and active in management domain
Gi0/0/0   1,399,1101
Gi0/3/3   1,399,1101

Port      Vlans in spanning tree forwarding state and not pruned
Gi0/0/0   1,399,1101
Gi0/3/3   1,399,1101
0
Comment
Question by:supportemea
  • 4
  • 3
  • 2
  • +1
10 Comments
 
LVL 16

Expert Comment

by:max_the_king
ID: 39237298
Hi,

i believe you need to add the following to interface configuration:

interface GigabitEthernet0/3/3
switchport trunk allowed vlan 1101
switchport mode trunk

hope this helps
max
0
 
LVL 16

Expert Comment

by:max_the_king
ID: 39237303
please note that you should add in that command all vlans you want to go through trunk, otherwise it will pass only vlan 1101

i.e.:
interface GigabitEthernet0/3/3
switchport trunk allowed vlan 1,399,1101
switchport mode trunk

should you want to trunk the 3 vlans 1,399 and 1101

max
0
 
LVL 2

Author Comment

by:supportemea
ID: 39237305
Hi Max,

Looks like it doesnt as I get the error

Command rejected: Bad VLAN allowed list. You have to include all default vlans, e.g. 1-2,1002-1005.
0
PRTG Network Monitor: Intuitive Network Monitoring

Network Monitoring is essential to ensure that computer systems and network devices are running. Use PRTG to monitor LANs, servers, websites, applications and devices, bandwidth, virtual environments, remote systems, IoT, and many more. PRTG is easy to set up & use.

 
LVL 16

Accepted Solution

by:
max_the_king earned 500 total points
ID: 39237323
Hi,
yes it may happen, please read the following (trunk section):
http://www.cisco.com/en/US/products/hw/modules/ps2797/products_configuration_example09186a00808066b8.shtml#step2

hope this helps
max
0
 
LVL 16

Expert Comment

by:max_the_king
ID: 39237329
however i wouldn't worry, you may want to have a look at this:
https://supportforums.cisco.com/thread/2167537

it is well explained
max
0
 
LVL 50

Expert Comment

by:Don Johnston
ID: 39237396
I’ve got a  Cisco CISCO2901/K9 router which I’m wanting to configure the GI0/3/3 port to a trunking port and only allow vlan 1101 over the trunk.
If you only want to allow one VLAN, why do you want a trunk?  This defeats the whole point of a trunk in the first place.
0
 
LVL 9

Expert Comment

by:BigPapaGotti
ID: 39237508
Try using the command below:

switchport trunk allowed vlan 1-1005,1101

This will specify the default vlans that need to be allowed as well as the only VLAN you want to traverse the link. Keep in mind that you need to enter this command under the appropriate interface for each side of the trunk's link.
0
 
LVL 9

Expert Comment

by:BigPapaGotti
ID: 39242656
Any updates
0
 
LVL 9

Expert Comment

by:BigPapaGotti
ID: 39260856
Any change/updates for us?
0
 
LVL 50

Expert Comment

by:Don Johnston
ID: 39260877
You in a hurry or something? :-)
0

Featured Post

Gigs: Get Your Project Delivered by an Expert

Select from freelancers specializing in everything from database administration to programming, who have proven themselves as experts in their field. Hire the best, collaborate easily, pay securely and get projects done right.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
Cant browse or ping a particular URL 2 32
Download Logs File from Cisco Switch 1 39
Vlan to Vlan communication 9 102
eigrp - not allow a subnet from advertising 1 35
There are two basic ways to configure a static route for Cisco IOS devices. I've written this article to highlight a case study comparing the configuration of a static route using the next-hop IP and the configuration of a static route using an outg…
In the world of WAN, QoS is a pretty important topic for most, if not all, networks. Some WAN technologies have QoS mechanisms built in, but others, such as some L2 WAN's, don't have QoS control in the provider cloud.
After creating this article (http://www.experts-exchange.com/articles/23699/Setup-Mikrotik-routers-with-OSPF.html), I decided to make a video (no audio) to show you how to configure the routers and run some trace routes and pings between the 7 sites…
After creating this article (http://www.experts-exchange.com/articles/23699/Setup-Mikrotik-routers-with-OSPF.html), I decided to make a video (no audio) to show you how to configure the routers and run some trace routes and pings between the 7 sites…

815 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

7 Experts available now in Live!

Get 1:1 Help Now