Vlan Interface going UP & DOWN

[Anand Narayana]

Hi,

I hav cisco 3750, juz a vlan 1 interface configured with a IP address & it is being uplinked to a un-managed switch, not after uplink this, vlan 1 inteface goes UP & DOWN, any reason for this, as a test, i connected only the uplink cable, only the vlan 101 is behaving like this, even if i connected few PC on other portz which is also in vlan 101, i still face this problem. can you help me in this regard, i also erased & re-configured the switch, but ended with no resultz.

00:23:15: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan1, changed state t

o up

00:23:41: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan1, changed state t

o down

[glen.grant]

You mention 2 different vlans , 101 and 1 . It appears that your uplink which is vlan 1 is probably bouncing . If this is the only link in vlan 1 then the SVI will go up and down as the link bounces. The other possibilty is you have turned off ip routing on the switch in which case you would only be able to have 1 SVI in a up condition . If you defined vlan 101 then int vlan 1 would go down.

[Anand Narayana]

Thanks for your reply glen,

But now once again I erased the configuration on cisco 3750 & juz VLAN 1 interface is there, I juz connected the uplink cable to Gi 1/0/24 port & till get the same problem that VLAN 1 interface going UP & DOWN.

Note: No other VLAN's are created on the switch.

[Anand Narayana]

Any help on this.