[c-nsp] VLAN disappeared

Thu Sep 22 12:56:26 EDT 2005

Additionally, you may want to limit the amount of VTP servers you have
within you L2 domain.  There are no technical reasons for this, other than
you don't want a device with a higher revision number that is missing VLANs
to propagate the subset of VLANs to switches with a lower VTP revision.

I usually set 2 switches as VTP servers per VTP domain.

On 9/22/05 10:53 AM, "Brian Desmond" <brian at briandesmond.com> wrote:

> 1. I'm pretty sure the 2950s support 256 not 64 like the 2900XLs. It's
> usually listed in the spec for the switch/supervisor.
> 
> 2. No. VTP pruning just makes it so switches do not receive non-directed
> (e.g. broadcast, multicast) traffic for vlans which they don't have ports
> under. You need to do an allowed vlans on the trunk port on the upstream
> switch to specify what vlans actually traverse the trunk link. VTP Pruning
> is a per vtp-domain setting, not per link.
> 
> Thanks,
> Brian Desmond
> brian at briandesmond.com
>  
>  
> 
> -----Original Message-----
> From: cisco-nsp-bounces at puck.nether.net
> [mailto:cisco-nsp-bounces at puck.nether.net] On Behalf Of Vincent De Keyzer
> Sent: Thursday, September 22, 2005 10:26 AM
> To: 'David Prall'; cisco-nsp at puck.nether.net
> Subject: RE: [c-nsp] VLAN disappeared
> 
> David,
> 
> thanks for the document for dummies.
> 
> Since this is a 2950, I am surprised to see that the limit is still 2950.
> 
> Two more questions then:
> 1) how do I know how many VLANs a switch supports? Is there a table
> somewhere on CCO that lists the max. number of VLAN per switch type, or do I
> have to dig the specs of each switch?
> 2) please confirm my understanding: when I do VLAN pruning on the trunk
> ports, the VLANs not listed as allowed (but present on the other switches of
> the VTP domain) will not enter the VTP database of the switch?
> 
> Vincent
> 
> 
>> -----Original Message-----
>> From: cisco-nsp-bounces at puck.nether.net [mailto:cisco-nsp-
>> bounces at puck.nether.net] On Behalf Of David Prall
>> Sent: jeudi 22 septembre 2005 15:39
>> To: 'Vincent De Keyzer'; cisco-nsp at puck.nether.net
>> Subject: RE: [c-nsp] VLAN disappeared
>> 
>> Vincent,
>> A number of the smaller switches have a 64 VLAN limit. What switch are you
>> using. On the trunk ports you might want to look at pruning all vlans
>> except
>> those that you require.
>> 
>> 2900XL
>> http://www.cisco.com/en/US/products/hw/switches/ps607/products_installatio
>> n_
>> and_configuration_guide_chapter09186a008007d32c.html
>> "A switch supports up to 64 VLANs"
>> 
>> David
>> 
>> --
>> David C Prall dcp at dcptech.com http://dcp.dcptech.com
>> 
>> 
>>> -----Original Message-----
>>> From: cisco-nsp-bounces at puck.nether.net
>>> [mailto:cisco-nsp-bounces at puck.nether.net] On Behalf Of
>>> Vincent De Keyzer
>>> Sent: Thursday, September 22, 2005 8:40 AM
>>> To: cisco-nsp at puck.nether.net
>>> Subject: [c-nsp] VLAN disappeared
>>> 
>>> Hello,
>>> 
>>> 
>>> 
>>> a VLAN disappeared from a switch this morning (obviously creating
>>> "side-problems").
>>> 
>>> 
>>> 
>>> When I realised this and tried to put it back, here is what
>>> the switch told
>>> me:
>>> 
>>> 
>>> 
>>> BRUBLUsw04#vlan database
>>> 
>>> BRUBLUsw04(vlan)#vlan 828
>>> 
>>> VLAN 828 added:
>>> 
>>>     Name: VLAN0828
>>> 
>>> BRUBLUsw04(vlan)#exit
>>> 
>>> Proposed configuration has too many VLANs for this device's
>>> core memory
>>> 
>>> resources.  Either reduce the number of VLANs proposed or use
>>> another VTP
>>> 
>>> device to configure database.  (The latter will cause this
>>> device to enter
>>> 
>>> TRANSPARENT mode automatically if propagated to it.)
>>> 
>>> APPLY failed.
>>> 
>>> Use 'abort' command to exit
>>> 
>>> BRUBLUsw04(vlan)#
>>> 
>>> 
>>> 
>>> So I looked up the VLAN, and found 204 that was not supposed
>>> to be there:
>>> 
>>> 
>>> 
>>> BRUBLUsw04(vlan)#no vlan 204
>>> 
>>> Deleting VLAN 204...
>>> 
>>> BRUBLUsw04(vlan)#vlan 828 name BRUBLU
>>> 
>>> VLAN 828 modified:
>>> 
>>>     Name: BRUBLU
>>> 
>>> BRUBLUsw04(vlan)#exit
>>> 
>>> APPLY completed.
>>> 
>>> Exiting....
>>> 
>>> BRUBLUsw04#
>>> 
>>> 
>>> 
>>> and everybody was happy again.
>>> 
>>> 
>>> 
>>> Now, being infamously incompetent in layer2 switches (among
>>> other things), I
>>> have the following questions:
>>> 
>>> What happened? Why did VLAN 828 suddenly disappear? If I turn
>>> this switch
>>> into a VTP client, and add VLANs on a VTP server, will this
>>> one be able to
>>> swallow all VLANs of the domain (at the moment, all switches
>>> in the VTP
>>> domain are servers)? Why would I want to have this switch
>>> VTP-transparent?
>>> How do I check the "core memory resources" consumption? etc.
>>> 
>>> 
>>> 
>>> . in other words: please advise.
>>> 
>>> 
>>> 
>>> Thanks in advance.
>>> 
>>> 
>>> 
>>> Vincent
>>> 
>>> 
>>> 
>>> 
>>> 
>>> _______________________________________________
>>> cisco-nsp mailing list  cisco-nsp at puck.nether.net
>>> https://puck.nether.net/mailman/listinfo/cisco-nsp
>>> archive at http://puck.nether.net/pipermail/cisco-nsp/
>>> 
>> 
>> _______________________________________________
>> cisco-nsp mailing list  cisco-nsp at puck.nether.net
>> https://puck.nether.net/mailman/listinfo/cisco-nsp
>> archive at http://puck.nether.net/pipermail/cisco-nsp/
> 
> _______________________________________________
> cisco-nsp mailing list  cisco-nsp at puck.nether.net
> https://puck.nether.net/mailman/listinfo/cisco-nsp
> archive at http://puck.nether.net/pipermail/cisco-nsp/
> 
> _______________________________________________
> cisco-nsp mailing list  cisco-nsp at puck.nether.net
> https://puck.nether.net/mailman/listinfo/cisco-nsp
> archive at http://puck.nether.net/pipermail/cisco-nsp/