Cisco 3850 - Cannot create VLANs

[Aaron Jones]

We recently installed some 3850 switches to do Layer 3 routing, moving this off a pair of Nexus 6001s.

The plan was to make the 3850 pair the VTP Domain server. But for some reason, it is not possible to create new VLANs on the 3850 pair. When a VLAN is created and named, exiting out of config mode displays the following message:

%Error exiting config-vlan mode 33: Attempt to change state of a default VLAN

And the VLAN is not created.

I cannot find anything under known bugs about this, has anyone seen this before?

[balaji.bandi]

check the VTP version, it should be version 2

also need soime clarification, you want nexus devices to be as VTP clients ?

post show vtp status from both the switches ?

[Aaron Jones]

Hi BB,

Yes, the plan is for the Nexus pair to now be clients in the VTP domain.

The version running is version 2:

#sh vtp status
VTP Version capable : 1 to 3
VTP version running : 2
VTP Domain Name : [redacted]
VTP Pruning Mode : Disabled
VTP Traps Generation : Disabled
Device ID : d4ad.71db.6680
Configuration last modified by [redacted] at 3-23-20 16:05:10
Local updater ID is [redacted] on interface Vl1 (lowest numbered VLAN interface found)

Feature VLAN:
--------------
VTP Operating Mode : Server
Maximum VLANs supported locally : 1005
Number of existing VLANs : 42
Configuration Revision : 144

Thank you for your response.

[balaji.bandi]

some odd issue i come acorss same, making nexus as VTP works with VTP v2

[Georg Pauwen]

Hello,

I would either:

--> delete the vlan.dat file in flash on the 3850, reload the 3850, and try again

--> make (one of) the Nexus switches the VTP server, and the 3850s the clients

[Aaron Jones]

Hi Georg,

We tried to delete the vlan.dat file in flash and reboot, but this did not resolve the issue.

Our current work around is to use the Nexus pair as the VTP server, and the 3850 pair as clients. This does work, VLANs created on the Nexus pair are then shared to the 3850 pair.

I just wanted to see if there was a solution to this issue, as my personal OCD has issues with it working in this way!

[jc_adrian30]

Hi Aaron,

Please try changing the VTP mode to transparent on Cat3850, create new vlan and then switch it back to VTP server mode and let´s see what happens. Check if you are using vtp version 2, because if you are using vtp version 2 your swtich wil only propagate vlans 1 to1005. When you  create new vlans, please create only vlans from 1 to 1000, because vlans1002 to 1005 are still reserved on system and cannot be modified.

One more thing, I have had some issue like flash: issues on stack members. Try to unpair both cat3850 from the stack and then reload and then try to create new vlans again.

Regards,

JC 

[Aaron Jones]

Hi JC,

Changing VTP mode to Transparent did not change the issue, unfortunately.

We are using vtp version 2. The test vlan I tried to create was number 123 - was under the 1000 limit.

I have not tried unpairing the stack yet, as it is used in production I will have to wait and arrange a time to do this.

Thank you for your suggestions.

[paul driver]

Hello
You may need to change the SDM template running on the switches
show sdm prefer

[Aaron Jones]

Hi Paul,

The current sdm template is as follows:

Showing SDM Template Info

This is the Advanced template.
Number of VLANs: 4094
Unicast MAC addresses: 32768
Overflow Unicast MAC addresses: 512
L2/L3 Multicast entries: 4096
Overflow L2/L3 Multicast entries: 512
Directly connected routes: 16384
Indirect routes: 7168
Security Access Control Entries: 3072
QoS Access Control Entries: 2560
Policy Based Routing ACEs: 1024
Netflow ACEs: 768
Flow SPAN ACEs: 512
Tunnels: 256
LISP Instance Mapping Entries: 256
Control Plane Entries: 512
Input Netflow flows: 8192
Output Netflow flows: 16384
SGT/DGT (or) MPLS VPN entries: 4096
SGT/DGT (or) MPLS VPN Overflow entries: 512
Wired clients: 2048
MPLS L3 VPN VRF: 127
MPLS Labels: 2048
MPLS L3 VPN Routes VRF Mode: 7168
MPLS L3 VPN Routes Prefix Mode: 3072
MVPN MDT Tunnels: 256
L2 VPN EOMPLS Attachment Circuit: 256
MAX VPLS Bridge Domains : 64
MAX VPLS Peers Per Bridge Domain: 8
MAX VPLS/VPWS Pseudowires : 256
These numbers are typical for L2 and IPv4 features.
Some features such as IPv6, use up double the entry size;
so only half as many entries can be created.

What template do you think might be better for my situation, do you think?