What happened here?

For the life of me I can't get my vlan lab working. I keep ending up having to reload both switches after clearing flash:vlan.dat and startup-config. Here's my current problem that's going to lead to me reloading again:

S1#sh ip int br
Interface IP-Address OK? Method Status Protocol
Vlan1 192.168.1.50 YES manual up up
Vlan2 192.168.2.50 YES manual administratively down down
Vlan3 192.168.3.50 YES manual up down
Vlan4 192.168.4.50 YES manual up down
Vlan99 192.168.99.50 YES manual up down

S1#sh vlan

VLAN Name Status Ports
----
1 default active Fa0/1, Fa0/2, Fa0/4, Fa0/5, Fa0/7, Fa0/8
Fa0/10, Fa0/11, Fa0/13, Fa0/14, Fa0/15
Fa0/16, Fa0/17, Fa0/18, Fa0/19, Fa0/20
Fa0/21, Fa0/22, Fa0/23, Fa0/24
1002 fddi-default act/unsup
1003 token-ring-default act/unsup
1004 fddinet-default act/unsup
1005 trnet-default act/unsup

S1(config)#int fa0/6
S1(config-if)#switchport mode trunk
S1(config-if)#switchport access vlan 2
% Access VLAN does not exist. Creating vlan 2
S1(config-if)#int fa0/9
S1(config-if)#switchport access vlan 3

The switch hung here, not even giving me a prompt.

OK; I realize assigning a port to a vlan as well as a trunk is totally wrong, but I'm not clear what caused it to hang? I can't access the switch again without reloading.

I switched to another computer that has a serial port, so I logged into console to show it rebooting (odd it didn't until I established the console connection though). One back in I created vlan2 again, but sure enough

Switch#sh vlan

VLAN Name Status Ports
----
1 default active Fa0/1, Fa0/2, Fa0/4, Fa0/5, Fa0/7, Fa0/8
Fa0/10, Fa0/11, Fa0/13, Fa0/14, Fa0/15
Fa0/16, Fa0/17, Fa0/18, Fa0/19, Fa0/20
Fa0/21, Fa0/22, Fa0/23, Fa0/24
1002 fddi-default act/unsup
1003 token-ring-default act/unsup
1004 fddinet-default act/unsup
1005 trnet-default act/unsup

What's going on?

[EDIT] A followup:

Switch#conf t
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)#int fa0/12
Switch(config-if)#swi
Switch(config-if)#switchport modfe
Switch(config-if)#switchport mode
Switch(config-if)#switchport mode acc
Switch(config-if)#switchport mode access
Switch(config-if)#swi
Switch(config-if)#switchport acc
Switch(config-if)#switchport access vl
Switch(config-if)#switchport access vlan 2

I've hung again. 0/12 is a crossover between the 2 switches.
Console connection was still up on the other computer. That last command put vlan 1 into administratively down???

Find more posts tagged with

Free for TechExams community: Cybersecurity salary guide

Compare cert salaries and plan your next career move

Button

Comments

gouki2005

hung sounds like a hardware problem or software corruption...

bermovick

I dunno; if I bring vlan 1 back up from the console connection, vlan 2 goes back to administratively down. I had this working before so not sure WHAT I'm doing wrong.

Monkerz

Try using "switchport trunk native vlan 2" "switchport trunk allowed vlan 2" instead of "switchport access vlan 2" on your trunk.

networker050184

Were you telneted into the switch on a VLAN 1 IP? What type of switch? You can only have one SVI up at a time on the older L2 only switches like the 2950s.

bermovick

Yeah, it's a 2950 and yes I was telnetted into Vlan1. I'm not sure what an SVI is? Google to the rescue!

Wait; so assigning the IP address creates the SVI? And since I have an ip assigned to each VLAN, I can only have 1 vlan up at a time? I'll have to investigate this.

Although I'm still not sure why sh vlan doesn't list the vlan's I've created. I may have a theory here where vlan 1 and vlan1 do different things, although both work. I'm going to clear/reload and investigate.

networker050184

Ok, creating the VLAN interface (AKA SVI = Switched Virtual Interface) does NOT create the VLAN in the database. You need to either use the vlan data base command or the global config mode command vlan [number].

You are correct only one SVI up up at a time on the 2950. When you assigned that port to VLAN 2 the SVI went up up and made VLAN 1 interface go down.

bermovick

OK, that part makes sense and I understand it; but I still don't understand why I'm not able to create vlans ... properly?

From a fully reset switch (I actually cleared & reloaded both in quick succession to keep VTP from messing things up). I've enabled secret & no login on vty 0 15 & assigned an address to vlan 1 so I can telnet in from here. Nothing else.

Switch>enable
Password:
Switch#sh ip int br
Interface IP-Address OK? Method Status Protocol
Vlan1 192.168.1.50 YES manual up up
FastEthernet0/1 unassigned YES unset down down
(etc)

Switch#sh vlan

VLAN Name Status Ports
----
1 default active Fa0/1, Fa0/2, Fa0/4, Fa0/5, Fa0/7, Fa0/8
Fa0/10, Fa0/11, Fa0/13, Fa0/14, Fa0/15
Fa0/16, Fa0/17, Fa0/18, Fa0/19, Fa0/20
Fa0/21, Fa0/22, Fa0/23, Fa0/24
1002 fddi-default act/unsup
(etc)

Switch(config)#int vlan 2
Switch(config-if)#na
Switch(config-if)#na?
% Unrecognized command
Switch(config-if)#name
^
% Invalid input detected at '^' marker.

Switch(config-if)#exit
Switch(config)#exit
Switch#sh ip int br
Interface IP-Address OK? Method Status Protocol
Vlan1 192.168.1.50 YES manual up up
Vlan2 unassigned YES unset administratively down down
FastEthernet0/1 unassigned YES unset down down
(etc)

Switch#sh vlan

VLAN Name Status Ports
----
1 default active Fa0/1, Fa0/2, Fa0/4, Fa0/5, Fa0/7, Fa0/8
Fa0/10, Fa0/11, Fa0/13, Fa0/14, Fa0/15
Fa0/16, Fa0/17, Fa0/18, Fa0/19, Fa0/20
Fa0/21, Fa0/22, Fa0/23, Fa0/24
1002 fddi-default act/unsup
(etc)

... I really don't get what's going on.

bermovick

Duh, nevermind. I think

networker050184

Leave off the interface part. Just vlan.

bermovick

Yeah, I realized that and all my problems of the last 6? hours have gone away now.