Solved: Re: VLAN interface down/down

wavess · ‎03-29-2022

Hi All

First post on here. Created vlan, then vlan interface, assigned ports, and status says down/down. I'm stuck. I've read other posts on this topic. Tried recreating everything, and still the same. At one point yesterday I got it to say up/down, but now its back to down/down. It is not admin down. And it appears to be flapping. Here is output from the show log command, and from show ip int brief, and from show vlan brief. Thanks for any suggestions.

Stephen

show log:

024393: Mar 27 18:42:30: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan53, changed state to down
024395: Mar 27 18:42:33: %LINK-3-UPDOWN: Interface Vlan53, changed state to up
024397: Mar 27 18:42:34: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan53, changed state to up
024399: Mar 27 21:45:12: %LINK-3-UPDOWN: Interface Vlan53, changed state to down
024401: Mar 27 21:45:13: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan53, changed state to down
024431: Mar 28 11:28:48: %LINK-3-UPDOWN: Interface Vlan53, changed state to up
024433: Mar 28 11:28:49: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan53, changed state to up
024435: Mar 28 11:29:26: %LINK-3-UPDOWN: Interface Vlan53, changed state to down
024437: Mar 28 11:29:27: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan53, changed state to down
024439: Mar 28 11:29:34: %LINK-3-UPDOWN: Interface Vlan53, changed state to up
024441: Mar 28 11:29:35: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan53, changed state to up
024443: Mar 28 11:30:28: %LINK-3-UPDOWN: Interface Vlan53, changed state to down
024445: Mar 28 11:30:29: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan53, changed state to down
024467: Mar 28 12:04:56: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan53, changed state to down
024486: Mar 28 15:53:34: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan53, changed state to up
024488: Mar 28 15:54:30: %LINK-3-UPDOWN: Interface Vlan53, changed state to down
024490: Mar 28 15:54:31: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan53, changed state to down
024494: Mar 28 15:58:09: %LINK-3-UPDOWN: Interface Vlan53, changed state to up
024496: Mar 28 15:58:10: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan53, changed state to up
024498: Mar 28 15:59:03: %LINK-3-UPDOWN: Interface Vlan53, changed state to down
024500: Mar 28 15:59:04: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan53, changed state to down
024514: Mar 28 16:52:08: %LINK-3-UPDOWN: Interface Vlan53, changed state to up
024516: Mar 28 16:52:09: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan53, changed state to up
024518: Mar 28 16:52:56: %LINK-3-UPDOWN: Interface Vlan53, changed state to down
024520: Mar 28 16:52:57: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan53, changed state to down
024522: Mar 28 16:53:25: %LINK-3-UPDOWN: Interface Vlan53, changed state to up
024524: Mar 28 16:53:26: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan53, changed state to up
024526: Mar 28 16:53:46: %LINK-3-UPDOWN: Interface Vlan53, changed state to down
024528: Mar 28 16:53:47: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan53, changed state to down
024538: Mar 28 20:24:56: %LINK-3-UPDOWN: Interface Vlan53, changed state to up
024540: Mar 28 20:24:57: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan53, changed state to up
024542: Mar 28 20:27:59: %LINK-3-UPDOWN: Interface Vlan53, changed state to down
024544: Mar 28 20:28:00: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan53, changed state to down

show vlan brief:

53 EMS_INTERNET_ONLY active Gi1/0/1, Gi1/0/2, Gi1/0/3
Gi2/0/4

show ip int brief:

Vlan53 10.5.3.1 YES manual down down

wavess · ‎03-30-2022

Jon

Yes, it is applied inbound. The pcs are getting a good ip, dns, and gateway, but no internet access. per the recommendation of Richard Burts, i'm gonna mark this issue as solved and start a new thread on the ACL.

In summary, i think this is the solution Jon was saying and Rich echoed. I didn't change any config on my end with this, but it is now working for some reason (gosh that's frustrating wish I knew why.) At any rate, will post a new topic on the ACL. thank you everyone.

SOLUTION:

create l2 vlan

creat l3 vlan interface

assign ports to vlan

a device must be on and plugged into the network so that you have an interface that is up in order for the vlan interface to come up, or the vlan must be on a trunk interface. this will get the vlan interface to come up.

View solution in original post

Jon Marshall · ‎03-29-2022

For the L3 interface (SVI) to be up/up you need one of the following -

1) an access port allocated to that vlan that is up/up

or

2) the vlan is added to a trunk link and that trunk is up/up

If you have allocated ports to that vlan but none of them are up/up then the SVI won't be up.

Jon

wavess · ‎03-29-2022

thanks Jon. I will try to go plug something into one of those ports to see if it brings things up.

I am still confused because at one point yesterday I blew everything away (vlan, vlan int, and default interfaced all four of the ports in the vlan). then when i recreated everything (vlan, vlan int, assigned ports of the vlan) the status said up/down, so i thought i was on track. now its back to down/down.

Jon Marshall · ‎03-29-2022

If you create the SVI but do not create the vlan in the vlan database it will show as down/down.

If you create the SVI and create the vlan in the vlan database it will show as up/down.

Jon

wavess · ‎03-29-2022

Okay, weird. I for sure created the vlan, and the vlan interface, and it is showing as down/down.

when I do show vlan brief I see the vlan, and when i do a show ip int brief i also see the vlan interface.

i'll try plugging something in again to see if that does anything.

paul driver · ‎03-29-2022

Hello

What is the status of those interfaces assinged to vlan 53,

Gi1/0/1, Gi1/0/2, Gi1/0/3, Gi2/0/4

Please rate and mark as an accepted solution if you have found any of the information provided useful.
This then could assist others on these forums to find a valuable answer and broadens the community’s global network.

Kind Regards
Paul

wavess · ‎03-29-2022

down/down on all 4 of them.

Jon Marshall · ‎03-29-2022

Have you connected anything to the ports ?

Jon

wavess · ‎03-29-2022

yesterday we had a device connected to one of the ports in the vlan, and nothing came up.

presently, there is nothing connected to any of the 4 ports in the vlan.

Flavio Miranda · ‎03-29-2022

It seems you have some problem. Which switch is it? which version?

Try to upgrade in case it is possible.

wavess · ‎03-29-2022

catalyst 9200. it is up to date to my knowledge.

MHM Cisco World · ‎03-29-2022

you have error-disable in these port so it down and finally make SVI down,
show ip interface status and confirm that.
the reason I think is there is Loop check

show ip spanning-tree vlan X detail
please share it here

wavess · ‎03-29-2022

I do not believe "show ip spinning tree vlan X detail" is an actual command.

The ports are not in error-disabled state per the logs.

MHM Cisco World · ‎03-29-2022

like this command
cat# show spanning-tree vlan 1 detail

wavess · ‎03-29-2022

update: when i assigned the vlan to a trunk port the interface vlan came up. I do not want that as a permanent config, so will remove it from trunk link. I will go test it this aft by plugging in a physical device to one of the ports in the vlan and see what happens. will keep you all posted. thanks for the help so far!