Cat9K: VTP (or PTP) over Management Interface

[BrianSekleckiGE]

Question for the Cisco Community hive mind:

• Can the Management interface on the Catalyst 9K carry VTP?
• For bonus: Can it carry PTP/IEEE1588?

I'm down the rabbit hole on a topology re-design (where a 3rd party firewall will separate groups switches), and I want to maintain a single VTP and PTP hierarchy.

Yes, I know, fact that I'm posting this question here is the biggest indicator that I should find my way out and burn my current draft!

[balaji.bandi]

Manangement interface mainly for Managing the device like OOB managment, its belong to VRF or just manangement

i do not believe you can use any of the purpose you thinking to do i guess (honestly never tested, never got that requirement to use mgmt - since we have many other ports to use for the same purpose uplink ports)

[Reza Sharifi]

Think of a management interface as a "host" interface, where you connect your switch to another switch to be accessible out-of-band for management. So, no VTP. PTP, etc.

HTH

[BrianSekleckiGE]

I'll try it and let you know which protocols pass (PTP, VTP, etc.)

[ashishr]

Hi @BrianSekleckiGE

Ethernet management port is not layer 2 switchport so VTP will not work on it. It is also not listed in supported features in configuration guide. PTP might work since it would be IP packet.

Supported Features on the Ethernet Management Port
https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst9500/software/release/16-10/configuration_guide/int_hw/b_1610_int_and_hw_9500_cg/configuring_ethernet_management_port.html

Thanks,

Ashish

[BrianSekleckiGE]

Real world testing on [ C9200-24P ] running XE v16.12.04 reveals that VTP works fine over "mangement0" interface aka "GigabitEthernet0/0" on this platform.

00CKA10SDZ02#sh vtp interface GigabitEthernet 0/0

Interface VTP Status
------------------------------------
GigabitEthernet0/0 enabled
00CKA10SDZ02#

And I verified that the VTP configuration revision counter increments when Gi0/0 RX a VTP update flood.

Unfortunately, I do not have access to a C9300 at the moment to check if PTP will flow over Mgmt0/0, but in the case of a genuine need/dependency on PTP, one would want redundant Layer2 paths to the Grandmaster anyway.  However, if one is just using PTP to sync the internal clock in the switch (for mgmt), then that would be ideal.  

[BrianSekleckiGE]

Also, if anyone know anyone high up inside Fortinet, maybe ask them to clue into PTP Boundary Clock mode for the FortiGate.