Solved: VLAN interface problem

manui31804 · ‎03-13-2013

Hi,

I had to configure remotely a new VLAN interface on a cisco switch that had this vlan configuration :

(I am connected remotely using telnet on 192.168.130.32)

interface Vlan1

ip address 192.168.130.32 255.255.255.0

no ip route-cache

!

So as I understood the vlan 1 is the default Vlan, and i can ping the ip address 192.168.130.32

I decided after that to create a new vlan 201 with ip adress 10.58.197.32 "corporate ip adress" :

interface Vlan201

ip address 10.58.197.32 255.255.255.0

no ip route-cache

shutdown

!

If I remember shutdown means the interface is just created but not available. So now i Have this vlan configuration :

!

interface Vlan1

ip address 192.168.130.32 255.255.255.0

no ip route-cache

!

interface Vlan201

ip address 10.58.197.32 255.255.255.0

no ip route-cache

shutdown

!

I used after that the command "no shutdown" on this interface vlan 201 and then I lost connection And I was unable anymore to ping the 192.168.130.32.

Can someone explain me why I can't ping anymore the 192.168.130.32 please?

I can't also ping the 10.58.197.32 but this is normal. The problem is that this switch is on a remote site and I can't access it anymore.

I have to do 500km to plug my console cable I suppose...

Thanks a lot for your help/explanation

emmanuel

Gregory Snipes · ‎03-14-2013

Well my bad, I had assumed the switch you were using was layer 3 capable. Looks like your problem is indeed that. As stated by Alain, the 2950 is not capable of having more then one SVI. In order to make this work in the way you are currently trying to, you will need to upgrade the switch.

However this does not preclude adding a second VLAN to the switch and trunking it off to a switch that does have layer 3 capability or a sub-interface on a router.

What does this switch connect back to?

View solution in original post

paul driver · ‎03-13-2013

Hello

Did you save your changes? - If not the quickest way to get this back is to get someone to power down/up the switch you have lost connection to?

or get the same person to plug in a console cable and have them to revert your changes

By the way this "10.58.197.32 "corporate ip address" was it your wan interface address?

res

Paul

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Paul

Gregory Snipes · ‎03-13-2013

I would need to see more of the configuration to be sure (and a diagram of how this is connected would be helpful too) but I would wager that this is an issue with the default gateway/route.

If you have input the "ip default-gateway" command into this device to point it out of its subnet then when you switch the device over into multilayer switching, the "ip default-gateway" command is no longer used and you must switch over to using a default route. The command to enter a default route is "ip route 0.0.0.0 0.0.0.0 ".

manui31804 · ‎03-13-2013

Thanks for your answers.

@pdriver, this is a good idea to restart the switch cause I saved the changes but before adding the command line "no shutdown" so that should work !

10.58.197.32 is a LAN adress you should see this switch as a simple layer 2 switch.

@Gregory, it is just delivering network to 2 or 3 offices nothing else and it is not suposed to do some multivlan routes but you're right, I had a default gateway that targeted the router of this site. if I understand, by adding a new vlan interface, this disable the default gateway so that should explain why I can't telnet on it.

I did this test on a little switch before doing that on the other ones.

Is it possible then to let the default gateway but to add another vlan interface ? like I was trying to do?

(I'm french and my english is not perfect, if you don't understand something, please ask ;-) )

Thanks again for your help

Gregory Snipes · ‎03-13-2013

You english is not a problem, defiantly better than my french.

There is no issue with switching this device over to multi layer switching. You just need to add a default route if you are going to. The "ip route 0.0.0.0 0.0.0.0 " is how you set this. It can be set in addition to the "ip default-gateway " command. The former will be used if the device is performing multi-layer switching, the later will be used if the device is performing only layer 2 switching.

Please let me know if this needs further clarification.

cadet alain · ‎03-14-2013

Hi,

if this is a pure L2 switch like a 2950 then it can't have more than one SVI up at the same time and so when you no shut the vlan 201 interface you put the vlan 1 interface down and as you were connected to that IP then you lost your telnet session.

Regards

Alain

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mahmoodmkl · ‎03-13-2013

Hi
Please let us know the model of this switch

Sent from Cisco Technical Support iPhone App

stephen jeffrey · ‎03-13-2013

Hi, Cant help with the origional issue. But a great command is the "reload in XX" command, the XX being how long before the switch reloads.just dont save any config as you go. If you make a mistake and disconnect yourself just go for a coffee and wait for the device to reload and be back where you started. Saved me quite a few miles driving. you can cancel by issuing the "reload cancel" if everything works.

hope that helps in the future.

shine pothen · ‎03-14-2013

please let me know the model number of the switch. from your issue it looks like the device should be a layer 2. that is why when u created a new vlan the oldworking vlan wnet inactive.

manui31804 · ‎03-14-2013

Hi everyone and thanks all for your answers, the swich is a 2959 24 ports

@gregory As I understand the default route should not be used on this switch I think cause it's a command line I suppose for a multi vlan rooting (I don't know if you understand multi vlan rooting we say "routage inter vlan" in french) and in this case I just want to add a vlan and an ip adress on its interface nothing else.

@cadet alain, thanks for the information. I think i misunderstood one thing. I used the interface Vlan command line but I saw there is also a vlan command without "interface". Instead of creating a vlan interface in my case it should be better to create a vlan that makes more sense for me what do you think about that?

@ Stephen Jeffrey, Thanks a lot for this tip ! So in case of crash or disconnection, the switch will reload automatically and I will be able to have some other tests this is great :-)

here is the configuration of the switch before I was disconnected and before I forced the "no shutdown":

Current configuration : 4237 bytes

!

version 12.1

no service pad

service timestamps debug uptime

service timestamps log uptime

service password-encryption

!

hostname sw-25

!

enable secret 5 $1$PgiB$I63D74GW1IEuuWoAVuyu2.

!

wrr-queue bandwidth 60 10 30 0

wrr-queue cos-map 1 0 1

wrr-queue cos-map 2 2 4

wrr-queue cos-map 3 3 6 7

wrr-queue cos-map 4 5

ip subnet-zero

!

no ip domain-lookup

!

spanning-tree mode pvst

no spanning-tree optimize bpdu transmission

spanning-tree extend system-id

!

interface FastEthernet0/1

switchport voice vlan 101