Failed to convert interface vlan

[jeronimo]

Hello,

Maybe I'm missing sth obvious, is this "normal"? :

Test_BEB:1(mgmt:vlan)#convert vlan 4046
WARNING: The existing mgmt interface will be deleted and re-created with the given parameters, please reconnect to the switch and issue 'mgmt convert-commit' command before the 120 second rollback timer expires.
Continue with this operation (y/n) ? y
Failed to convert interface vlan

It's creating vlan 4046 ("vlan create 4046 type port-mstprstp 0") but neither attaching it to an i-sid nor converting it to mgmt. (previous platform vlan is 4047)

Tried this on 5320-24P-8XE (FE 9.0.4), 5320-24P-8XE (FE 9.2.0), 5520-48P (FE 8.10.3.0), behavior is the same "failed to convert"

Are there any prerequisites for this to work?

Thx

[gfriedl]

Just specify all the required paraemters within the convert command - it' much more than just a VLAN-ID, that is required:

for example (mgmt:vlan)#convert vlan 1 i-sid 111 ip 1.1.1.1/24 gateway 1.1.1.254

[jeronimo]

Well, that's not really the issue. You actually just have to run it twice, as shown below. It will keep the other settings. The first time there is an error, the second time it works / does the rest.

BEB2:1(mgmt:vlan)#convert vlan 4045
WARNING: The existing mgmt interface will be deleted and re-created with the given parameters, please reconnect to the switch and issue 'mgmt convert-commit' command before the 120 second rollback timer expires.
Continue with this operation (y/n) ? y
Failed to convert interface vlan
BEB2:1(mgmt:vlan)#1 2025-07-17T17:06:50.495+02:00 BEB2 CP1 - 0x003c867f - 00000000 Mgmt NLS_BASE ERROR Convert on mgmt vlan instance: Mgmt convert error: Could not add some ARP ports to vlan

BEB2:1(mgmt:vlan)#convert vlan 4045
WARNING: The existing mgmt interface will be deleted and re-created with the given parameters, please reconnect to the switch and issue 'mgmt convert-commit' command before the 120 second rollback timer expires.
Continue with this operation (y/n) ? y
BEB2:1(mgmt:vlan)#1 2025-07-17T17:06:54.652+02:00 BEB2 CP1 - 0x000c85a6 - 00000000 Mgmt SW INFO NTP is enabled and all mgmt instances were deleted! NTP won't be able to operate correctly!
1 2025-07-17T17:06:54.653+02:00 BEB2 CP1 - 0x003c8672 - 00000000 GlobalRouter NLS_BASE INFO Mgmt convert: existing mgmt vlan instance deleted successfully
1 2025-07-17T17:06:54.878+02:00 BEB2 CP1 - 0x003c8673 - 00000000 GlobalRouter NLS_BASE INFO Mgmt convert: new mgmt vlan instance created successfully with IP address 192.168.84.103/21

1 2025-07-17T17:06:54.922+02:00 BEB2 CP1 - 0x003c8676 - 00000000 GlobalRouter NLS_BASE INFO Mgmt convert: re-adding static route 0.0.0.0/0 with next-hop 192.168.80.1 to mgmt vlan instance
1 2025-07-17T17:06:54.922+02:00 BEB2 CP1 - 0x003c867e - 00000000 Mgmt NLS_BASE INFO Convert on mgmt vlan instance: Mgmt convert executed successfully

 But all that won't work if you have the PVLAN attached to an i-sid which you want to just keep the same.
a) if you don't specify an i-sid it will only swap the vlan
b) if you specify the same i-sid it will error out

[RobertD1]

I tried in GNS3 with 8.10.1 and it works without an error. It only prompts to say an IP is required beforehand. The onboarding VLAN 4048 is the Mgmt VLAN by default in my case. I used convert vlan 4046 and it create the VLAN in running-config and changes the mgmt VLAN from 4048 to 4046 and keeps same IP. Is your problem because ARP ports exist? And by trying once the ARP ports are removed and the second attempt works?

[jeronimo]

I tested on 9.2.0.0 and 9.0.4.0.

I do not do anything else not shown between first and second run of command.