01-21-2008 03:30 AM - edited 03-05-2019 08:36 PM
Hi
I've just configured the following port on my 3560G switch:
interface FastEthernet0/48
description Link Router (2Mbit Connection)
switchport trunk encapsulation dot1q
switchport trunk native vlan 10
switchport mode trunk
speed 100
duplex full
srr-queue bandwidth share 10 10 60 20
srr-queue bandwidth shape 10 0 0 0
priority-queue out
mls qos trust dscp
auto qos voip trust
no mdix auto
The strange thing is that this port shows up in vlan 1 when I run "sh vlan br"
1 default active Fa0/48
Could someone please tell me why that is, even though the native vlan is set to 10?
Thanks
Dan
Solved! Go to Solution.
01-21-2008 03:34 AM
Dan
Because it is not running as a trunk link. I have just done the same thing and when i shutdown the port it shows up in vlan 1.
If the port was up and running and functioning as a trunk then when you run "sh vlan brief" you won't see it attached to any vlan.
The native vlan is only the vlan that traffic will be sent untagged for. Until that port is functioning as a trunk it will remain allocated to the default vlan (unless you change it) which is vlan 1.
Jon
01-21-2008 03:34 AM
Dan
Because it is not running as a trunk link. I have just done the same thing and when i shutdown the port it shows up in vlan 1.
If the port was up and running and functioning as a trunk then when you run "sh vlan brief" you won't see it attached to any vlan.
The native vlan is only the vlan that traffic will be sent untagged for. Until that port is functioning as a trunk it will remain allocated to the default vlan (unless you change it) which is vlan 1.
Jon
01-21-2008 03:51 AM
Hi
Thanks for the reply. As a follow up question, is it safe to shutdown int vlan1 then? Or am I getting my understanding confused by what shutdown means?
Thanks
Dan
01-21-2008 03:53 AM
Dan
When i said shut the port down i meant the physical port not the L3 vlan interface.
Is this what you meant ?
Jon
01-21-2008 04:13 AM
Hi
Sorry what I meant was can I run
int vlan 1
shutdown
Would this in anyway affect the switch, since I assume vlan 1 by default is enabled.
I'm using a trunk link between a router that is routing for different vlans in one of our sites, other than the ones I've configured on the actual switch.
Thanks
Dan
01-21-2008 04:17 AM
Dan
If vlan 1 is not being used as a vlan for clients that are active and vlan 1 is not being used as the vlan to get access to the actual switch then yes you can shutdown the L3 vlan 1 interface.
As Narayan pointed out routing all your vlans on the 3560 would appear to make more sense but then you know your topology better than we do.
Jon
01-21-2008 03:46 AM
On a dot1q trunk, the native vlan traffic is sent untagged.
Since you have not configured any switchport access vlan
BTW can you let me know why are you using dot1q trunks while connecting to the router? are you running router on a stick topology? Creating the SVIs on the 3560 would make more sense in this case
HTH
Narayan
01-21-2008 05:46 AM
Narayan is corrrect because the access port was not set to anything by default it is in vlan 1 so your display is correct . If it wasn't a trunk and had a "switchport access vlan statement it would then show whatever vlan was in that statement.
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