Cannot access switch after no shut command on VLAN 99

[rmiller]

I have a switch that is accessed at ip 10.25.200.239 and I want to get rid of the 200 VLAN and access the switch through my management VLAN 99 but was unable to ping the switch on 10.25.99.239. I telnetted into the switch and pulled the status of the interface with sho int vlan 99 and got this:

Service1#sho interface vlan 99
Vlan99 is administratively down, line protocol is down
  Hardware is CPU Interface, address is 000f.8f31.9b80 (bia 000f.8f31.9b80)
  Description: Management Vlan
  Internet address is 10.25.99.239/24
  MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input never, output never, output hang never
  Last clearing of "show interface" counters never
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 0 bits/sec, 0 packets/sec
  5 minute output rate 0 bits/sec, 0 packets/sec
     0 packets input, 0 bytes, 0 no buffer
     Received 0 broadcasts (0 IP multicast)
     0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     0 packets output, 0 bytes, 0 underruns
     0 output errors, 1 interface resets
     0 output buffer failures, 0 output buffers swapped out

Since the VLAN was showing as administratively shut down I though I could bring it up by going into conf t and issuing the command no shut, which I did. As soon as I did this I can no longer access the switch on any ip. What happened and how do I reverse it so I can get back into the switch?

[Mark Malone]

console in and shut it back down or reboot the switch to regain access once you didnt save after the no shut

hard to say what happened without seeing full config on the switch

[Richard Burts]

Can the original poster provide information about what kind of switch this is and how it is configured? Especially important is whether the switch is a layer 3 switch or a layer 2 only switch. I have seen layer 2 only switches that allow only a single layer 3 SVI to be active (if you configure a second layer 3 SVI to be active then the switch puts the other layer 3 SVI as shutdown). I am wondering if that is what is happening here.

HTH

Rick 

[rmiller]

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@Richard Burts wrote:

Can the original poster provide information about what kind of switch this is and how it is configured? Especially important is whether the switch is a layer 3 switch or a layer 2 only switch. I have seen layer 2 only switches that allow only a single layer 3 SVI to be active (if you configure a second layer 3 SVI to be active then the switch puts the other layer 3 SVI as shutdown). I am wondering if that is what is happening here.

HTH

Rick 

---

This is a Cisco C2950G-24 and is an L2 switch.

[paul driver · Accepted solution]

Hello

Sounds like the switch has disabled the old SVI when you brought the new one up, And as Rick has stated some Access-switchs ONLY allow the activation of a single SVI interface

Now If your switch has a directly attached neighbor you should be able to gain access to this lost switch via that neighbor.

This is done by a feature called Clustering, Basically you access a directly connected neighboring parent switch and apply clustering on that device and then you should able to gain access any of it switches it  has attached

Caveats –

• Require access to the directly attached neighboring parent switch
• Need to know the privilege exec password of the switch your trying to connect to
• Clustering needs to be supported on the parent switch/access switch

Example:  Parent switch

Conf t

Cluster enable STAN
do show cluster candidates  <-  this will show any directly connected switches base mac- address

cluster member 10 mac-address xxxx.xxxx.xxxx password ???( enable password of remote switch)

sh cluster members  <------ should see your switch now being a member
do rcommand 10

@mark/Rick -  whilst I have brought this up , I was wandering if you know of any other way to gain L2 access to a switch as clustering doesn't seem to be supported on some of the newer ios of switching kit?

I have been trying to find out,,,not had any luck so far.

res
Paul

[rmiller]

---

---

do rcommand 10

I have created the cluster and added the member and it shows up but I haven't run the command do rcommand 10 yet. I still can't ping the other switch or access it via Putty.

What is do rcommand 10  and how then do I access the switch?

[paul driver]

Hello
It will connect with the rc command
That’s it

Res
Paul

[rmiller]

---

@paul driver wrote:

Hello

Sounds like the switch has disabled the old SVI when you brought the new one up, And as Rick has stated some Access-switchs ONLY allow the activation of a single SVI interface

Now If your switch has a directly attached neighbor you should be able to gain access to this lost switch via that neighbor.

This is done by a feature called Clustering, Basically you access a directly connected neighboring parent switch and apply clustering on that device and then you should able to gain access any of it switches it  has attached

Caveats –

• Require access to the directly attached neighboring parent switch
• Need to know the privilege exec password of the switch your trying to connect to
• Clustering needs to be supported on the parent switch/access switch

Example:  Parent switch

Conf t

Cluster enable STAN
do show cluster candidates  <-  this will show any directly connected switches base mac- address

cluster member 10 mac-address xxxx.xxxx.xxxx password ???( enable password of remote switch)

sh cluster members  <------ should see your switch now being a member
do rcommand 10

Ah! I see now that the switch can now be accessed as part of the cluster in CNA. The problem was that my management VLAN 99 was not active on the other switch to which my switch was attached, i.e. the host in the cluster. Now that I have enabled VLAN 99 on that switch I can access my switch through the management VLAN. Thank you!