Issue with vlan going up and down

[krranjith]

I have connected an ASA 5520 firewall DMZ to SERVER (17) vlan in core  switch and INSIDE is connected as trunk to the core switch (including  vlan 15,18). now the management ip of the switch is 10.xx.xx.126/25. and  the other vlans are showing "administratively down"..but if I enter to  any of the other vlans and do a "no shut", that particular vlan wil go  UP but the other 2 will go down..means only one vlan become up at a  time....what could be the cause??? Please help….

[Jon Marshall]

What model of switch is the core switch ?

With a L2 switch you can only have one vlan up at any one time. If you want multiple L3 vlan interfaces on a switch then the switch needs to be L3.

Jon

[krranjith]

switch is cisco 2950

[mvsheik123]

What switch you are using and what is the image. For a basic L2 switch, I guess you can have only one Vlan interface (L3 interface) up at any given time.

Hth

MS

[mvsheik123]

2950- supports only one L3 interface up at any given time.Go for 35xx switch.

hth

MS