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Vlan UP line protocol Down

jmoss1
Level 1
Level 1

I have a 3560 switch newly installed and have created a mgmt VLAN (999) but the line prot is down and won't come up

Vlan 1 is shut down and 2 other vlan's exist Vlan 2 (user data) and vlan 700 (voice) which work fine

Users are plugged in and working, vlan exists in vlan.dat etc

What am I missing?

config attached

thanks in advance

Jonathan

1 Accepted Solution

Accepted Solutions

Ganesh Hariharan
VIP Alumni
VIP Alumni

I have a 3560 switch newly installed and have created a mgmt VLAN (999) but the line prot is down and won't come up

Vlan 1 is shut down and 2 other vlan's exist Vlan 2 (user data) and vlan 700 (voice) which work fine

Users are plugged in and working, vlan exists in vlan.dat etc

What am I missing?

config attached

thanks in advance

Jonathan

Hi Jonathan,

It is because of Autostate is implemented on CatOS and IOS Cisco based switches by default. On some CatOS platforms, this feature can be disabled in order to allow redundancy in special scenarios. On IOS based switches, this feature cannot be disabled.

The router VLAN interfaces have to fulfill the following general conditions to be up/up:

    *  VLAN exists and is in active status on the switch VLAN database.

    *  VLAN interface exists on the router and is not administratively down.

    *  At least one L2 (access port or trunk) port exists and has a link up on this VLAN. The latest implementation of the autostate feature allows synchronization to Spanning-Tree Protocol (STP) port status.A VLAN interface will be brought up after the L2 port has had time to converge (that is, transition from listening-learning to forwarding). This will prevent routing protocols and other features from using the VLAN interface as if it were fully operational. This also prevents other problems, such as routing black holes, from occurring.

    * At least one L2 (access port or trunk) port is in spanning-tree forwarding state on the VLAN.

Hope to Help !!

If helpful do rate the post

Ganesh.H

View solution in original post

10 Replies 10

csc010627097
Level 1
Level 1

Hi, you need to assigne at least one device to this vlan to make protocole up.

HTH

Regards

Hi,

Atleast one interface you need to assign to this vlan(999).

Then only this vlan wil comes up.

regards

karuppu

this worked, thanks!

Ganesh Hariharan
VIP Alumni
VIP Alumni

I have a 3560 switch newly installed and have created a mgmt VLAN (999) but the line prot is down and won't come up

Vlan 1 is shut down and 2 other vlan's exist Vlan 2 (user data) and vlan 700 (voice) which work fine

Users are plugged in and working, vlan exists in vlan.dat etc

What am I missing?

config attached

thanks in advance

Jonathan

Hi Jonathan,

It is because of Autostate is implemented on CatOS and IOS Cisco based switches by default. On some CatOS platforms, this feature can be disabled in order to allow redundancy in special scenarios. On IOS based switches, this feature cannot be disabled.

The router VLAN interfaces have to fulfill the following general conditions to be up/up:

    *  VLAN exists and is in active status on the switch VLAN database.

    *  VLAN interface exists on the router and is not administratively down.

    *  At least one L2 (access port or trunk) port exists and has a link up on this VLAN. The latest implementation of the autostate feature allows synchronization to Spanning-Tree Protocol (STP) port status.A VLAN interface will be brought up after the L2 port has had time to converge (that is, transition from listening-learning to forwarding). This will prevent routing protocols and other features from using the VLAN interface as if it were fully operational. This also prevents other problems, such as routing black holes, from occurring.

    * At least one L2 (access port or trunk) port is in spanning-tree forwarding state on the VLAN.

Hope to Help !!

If helpful do rate the post

Ganesh.H

Hello Ganesh,

 

This was so helpful.

 

Regards,

 

Azhar M

Thank You. Once I assign the VLAN to access or the Trunk Port. The Protocol converts to up.

Hi folks,

 

Am having one doubt,in cisco packet tracer of model 2900 series router has vlan,but line protocol is down,please help here how to make it up,(we know in switches by assigning one link up interface to the vlan makes line protocol up),this is router right?

 

Please help here.

 

Regards

T.Manoj kumar

i hv same issue ...Vlan10 is up, line protocol is down .

 

 

CSS2#sh run int vlan 10
Building configuration...

Current configuration : 88 bytes
!
interface Vlan10
ip vrf forwarding BEARER
ip address 172.1.1.2 255.255.255.252
end

CSS2#sh run int fastEthernet 1/0
Building configuration...

Current configuration : 73 bytes
!
interface FastEthernet1/0
vlan-id dot1q 10
exit-vlan-config
!
end

 

CSS2#sh version
Cisco IOS Software, 3700 Software (C3725-ADVENTERPRISEK9-M), Version 12.4(15)T14, RELEASE SOFTWARE (fc2)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2010 by Cisco Systems, Inc.
Compiled Tue 17-Aug-10 12:08 by prod_rel_team

ROM: ROMMON Emulation Microcode
ROM: 3700 Software (C3725-ADVENTERPRISEK9-M), Version 12.4(15)T14, RELEASE SOFTWARE (fc2)

 

Can you try this configuration instead:

 

interface fa1/0

no vlan-id dot1q 10

switchport mode access 

switchport access vlan 10 

 

Regards,

Harold Ritter
Sr Technical Leader
CCIE 4168 (R&S, SP)
harold@cisco.com
México móvil: +52 1 55 8312 4915
Cisco México
Paseo de la Reforma 222
Piso 19
Cuauhtémoc, Juárez
Ciudad de México, 06600
México

MarcoLazzarotto
Level 1
Level 1

What if I want to have a VLAN dedicated for management? A VLAN which exists on the switch but has no ports in access mode?
I would connect to the VLAN interface from a pc connected on another switch.

 

PC1(VLAN10)<->(VLAN10)SW1(VLAN99) <-> SW2(VLAN99) <-> MGMT PC(VLAN99)

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