Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Announcements

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. If you'd prefer to explore, try our test area to get started. And see here for current known issues.

New Member

VLAN interface down/down

I configured a VLAN and a corresponding interface vlan with a certain ip subnet on a cat 6506 with sup 720. Unfortunately the vlan interface doesn?t come up. I also assigned a switchport to that vlan an connected an end device, which is configured with an ip address in the same subnet. Why doen?t the vlan interface come up?

BR,

Martin Funke.

8 REPLIES

Re: VLAN interface down/down

Hi,

Have you entered the "no shut" command in the vlan interface configuration command?

Can you post your 'Show run interface vlan no' output??

Have you made any members to the vlan? If yes, post the 'show run interface fa no' output of the interface which is a member of the vlan.

Regards,

AbhisheK

Please rate all posts!!!

New Member

Re: VLAN interface down/down

vlan 301

name ZD_AD/172.30.1.0/24

end

interface Vlan301

description *** zd_301/172.30.1.0/24 ***

ip vrf forwarding ZD_AD_301

ip address 172.30.1.243 255.255.255.0

no ip redirects

ip directed-broadcast

no ip proxy-arp

end

interface GigabitEthernet1/40

switchport access vlan 301

switchport mode access

end

DC_H11_ZGR10_02#sh int vlan 301

Vlan301 is down, line protocol is down

Hardware is Ethernet SVI, address is 0014.69d5.11ff (bia 0014.69d5.11ff)

Description: *** zd_301/172.30.1.0/24 ***

Internet address is 172.30.1.243/24

MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,

reliability 255/255, txload 1/255, rxload 1/255

Encapsulation ARPA, loopback not set

ARP type: ARPA, ARP Timeout 04:00:00

Last input 00:40:20, output never, output hang never

Last clearing of "show interface" counters never

Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0

Queueing strategy: fifo

Output queue: 0/40 (size/max)

5 minute input rate 0 bits/sec, 0 packets/sec

5 minute output rate 0 bits/sec, 0 packets/sec

L3 in Switched: ucast: 0 pkt, 0 bytes - mcast: 0 pkt, 0 bytes

L3 out Switched: ucast: 0 pkt, 0 bytes - mcast: 0 pkt, 0 bytes

3 packets input, 234 bytes, 0 no buffer

Received 3 broadcasts (0 IP multicast)

0 runts, 0 giants, 0 throttles

0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored

3 packets output, 138 bytes, 0 underruns

0 output errors, 0 interface resets

DC_H11_ZGR10_02#conf t

Enter configuration commands, one per line. End with CNTL/Z.

DC_H11_ZGR10_02(config)#int vlan 301

DC_H11_ZGR10_02(config-if)#sh

DC_H11_ZGR10_02(config-if)#no sh

DC_H11_ZGR10_02(config-if)#^Z

DC_H11_ZGR10_02#

DC_H11_ZGR10_02#sh int gi 1/40

GigabitEthernet1/40 is down, line protocol is down (notconnect)

Hardware is Gigabit Ethernet Port, address is 0014.69d5.11e7 (bia 0014.69d5.11e7)

Description: **** Test - Funke itk ****

MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,

reliability 255/255, txload 1/255, rxload 1/255

Encapsulation ARPA, loopback not set

Keepalive set (10 sec)

Auto-duplex, Auto-speed, link type is auto, media type is 10/100/1000-TX

input flow-control is off, output flow-control is off

ARP type: ARPA, ARP Timeout 04:00:00

Last input never, output never, output hang never

Last clearing of "show interface" counters never

Input queue: 0/2000/0/0 (size/max/drops/flushes); Total output drops: 0

Queueing strategy: fifo

Output queue: 0/40 (size/max)

5 minute input rate 0 bits/sec, 0 packets/sec

5 minute output rate 0 bits/sec, 0 packets/sec

0 packets input, 0 bytes, 0 no buffer

Received 0 broadcasts (0 multicast)

0 runts, 0 giants, 0 throttles

0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored

0 input packets with dribble condition detected

0 packets output, 0 bytes, 0 underruns

0 output errors, 0 collisions, 0 interface resets

0 babbles, 0 late collision, 0 deferred

0 lost carrier, 0 no carrier

0 output buffer failures, 0 output buffers swapped out

DC_H11_ZGR10_02#

Re: VLAN interface down/down

" GigabitEthernet1/40 is down, line protocol is down (notconnect) "

It says not connected. AFAIK This indicates that there is a fault in the connection with the interface or the cable which you are using to connect to the interface is faulty. Try replacing the cable.

Also please post the output of 'Show vlan' command.

I didnt understand what you wanted to say in the other post of yours. Can you please clarify?

Regards,

AbhisheK

Re: VLAN interface down/down

It is normal that the layer-3 VLAN interface will be down until there is a physical port up on the VLAN, either as an access port or as part of a trunk port. However, here you seem to be saying that you have put a physival port on the VLAN, and it is up. Could you do a show spanning-tree vlan n to verify that the access port really is in the VLAN? Also, do a show vlan to verify that the vlan really is active in your database.

The ip address of your end-device is important for its own connectivity, but is irrelevent as far as the up/down state of the vlan interface is concerned.

Kevin Dorrell

Luxembourg

New Member

Re: VLAN interface down/down

I?m connected to the internet and the the customers vpn-gateway through a prepaid wlan and I?m running out of time. So to shorten it a little bit: Is is also necessary for the vlan interface that there is a L3-device in the same ip-subnet connected to the vlan-port?

Thank you.

Martin.

Gold

Re: VLAN interface down/down

To actually get the vlan to be up/up you will need a real device in some way connected to the vlan.

The short answer to your last question is yes you need another device in the same layer 3 subnet to have this port come active. What purpose would it serve to have a vlan interface that could not communicate with anyother device.

The longer answer is that the switch is too stupid to know if deive is layer 3 or not. As long as any port on the switch is in the same vlan as the vlan interface and is electrically up the vlan interface will go into a up/up state. You could plug a empty hub into a copper access port and it will come up.

Another thing to check but more than likely not your problem. Make sure your vlans are defined in the vlan database. In most cases these will be created automatically when you assigne them to ports but if they don't you can get down/down status even with active ports.

New Member

Re: VLAN interface down/down

What you write sounds logic. I also thought, it should work only under the conditions described above.

But what about this:

DC_H11_ZGR10_02#sh int vlan 301

Vlan301 is up, line protocol is up

Hardware is Ethernet SVI, address is 0014.69d5.11ff (bia 0014.69d5.11ff)

Description: *** zd_301/172.30.1.0/24 ***

Internet address is 172.30.1.243/24

MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,

reliability 255/255, txload 1/255, rxload 1/255

Encapsulation ARPA, loopback not set

ARP type: ARPA, ARP Timeout 04:00:00

Last input 00:00:00, output never, output hang never

Last clearing of "show interface" counters never

Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0

Queueing strategy: fifo

Output queue: 0/40 (size/max)

5 minute input rate 0 bits/sec, 0 packets/sec

5 minute output rate 0 bits/sec, 0 packets/sec

L3 in Switched: ucast: 0 pkt, 0 bytes - mcast: 0 pkt, 0 bytes

L3 out Switched: ucast: 0 pkt, 0 bytes - mcast: 0 pkt, 0 bytes

0 packets input, 0 bytes, 0 no buffer

Received 0 broadcasts (0 IP multicast)

0 runts, 0 giants, 0 throttles

0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored

385 packets output, 18462 bytes, 0 underruns

0 output errors, 0 interface resets

0 output buffer failures, 0 output buffers swapped out

DC_H11_ZGR10_02#

DC_H11_ZGR10_02#sh vlan id 301

VLAN Name Status Ports

---- -------------------------------- --------- -------------------------------

301 ZD_AD/172.30.1.0/24 active Gi1/1, Gi1/40

VLAN Type SAID MTU Parent RingNo BridgeNo Stp BrdgMode Trans1 Trans2

---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------

301 enet 100301 1500 - - - - - 0 0

Remote SPAN VLAN

----------------

Disabled

Primary Secondary Type Ports

------- --------- ----------------- ------------------------------------------

DC_H11_ZGR10_02# sh ip int brief

[...]

GigabitEthernet1/40 unassigned YES unset down down

GigabitEthernet1/41 unassigned YES unset down down

[...]

How can this behavior be explained?

Best regards,

Martin.

Re: VLAN interface down/down

Martin,

Gig1/40 is shut down. What's the status of your Gig1/1 port? It has got to be up and it's either an access port on vlan301 or a trunk.

Regards,

Sundar

1385
Views
10
Helpful
8
Replies