Re: Cisco 2950 Telnet stops working after i no shut vlan

brendannash · ‎04-23-2010

standalone 2950 mainly in default config. I have assigned vlan 100 and assigned to FA0/19,20 no ip address When i do a no shutdown on the interface Vlan 100 I lose the telnet session. all other ports on default vlan 1. i want to broadcast NTP to another network than that of Vlan1. all these have no internet connection and no router on the network.

i want existing Vlan 1 as is and add a vlan to connect another devise and supply from cisco time via ntp to other box on another network

Please see attached tech supp

thank you

Brendan

kerek · ‎04-23-2010

Hi,

I'm afraid this will not be possible with this setup since 2950 is not L3 device.

The reason why lost the connection is you have enabled another SVI so the previous one went down automatically.

If you have console access you will see interface vlan 1 down/down.

You can have only one SVI active at the same time on L2 switches only for mgmt. purposes.

Hope this helps, rate if does

Krisztian

Giuseppe Larosa · ‎04-23-2010

Hello Brendan.

Krisztian is absolutely right: as soon as you have enabled vlan100 the switch puts in admin down vlan1.

I saw this some years ago while doing tests

intervlan routing has to be done by another device

Hope to help

Giuseppe

brendannash · ‎04-23-2010

Giuseppe

thank you for the comment.

as i understand it the if i use a new vlan 200 for existing devises and

vlan 100 for my NTP and assign the ip address

to the new vlan that both vlans 100 and 200 will be operational. note I

presently have NTP supplied from Vlan 1 for existing devices.

copy this to vlan200 and enable vlan100 for ntp also for the devices on

this vlan

i hope this makes sense

Brendan

Brendan Nash

Christian August Thorings veg 7

4003, Stavanger, Rogaland Norway, NORWAY

Phone: +47 24165282

Mobile: +353 872253273

email: brendan.nash@no.abb.com

kerek · ‎04-23-2010

Hi Brandan,

If I undersood correctly you have 2 vlans with two subnets. Your ntp is server in one of the vlans and you want to reach this ntp server from a different vlan.

With that L2 switch you will not be able to do that since it cannot route between the two vlans.

If your ntp server has two NICs you can connect the second NIC to the same switch and put in the other vlan or put a router which can router between the two vlans.

Hoep this helps, rate if does

Krisztian

brendannash · ‎04-23-2010

Dear All

thank you for the help on this one I am under control now.

please confirm that if another vlan or vlans are added then the default

vlan 1 is forced down.

thanks

Brendan

Brendan Nash

Christian August Thorings veg 7

4003, Stavanger, Rogaland Norway, NORWAY

Phone: +47 24165282

Mobile: +353 872253273

email: brendan.nash@no.abb.com

Jon Marshall · ‎04-23-2010

brendannash wrote:

Dear All

thank you for the help on this one I am under control now.

please confirm that if another vlan or vlans are added then the default

vlan 1 is forced down.

thanks

Brendan

You can have multiple L2 vlans on the switch ie. "sh vlan brief" shows your vlans at L2.

However, as has been said, you can only have one L3 SVI up/up ie.

interface vlan

ip address x.x.x.x

Jon

ronaldobf · ‎04-23-2010

Just an add: For security and design puposes, you should not use the VLAN 1. Shut it down and use another VLAN as management.