Error While trying to change VLAN Subnet [HP Switch 5412Rzl2 (J9851A) ]

[Manu83]

Hello Everybody

I have some trouble while trying to change the VLAN Subnet Mask.

I have tried from GUI Mode and CLI mode also.

Error Says Configuration Failed.

Thanks.

Please Help to change the Subnet Mask.

[akg7]

Hi,

Can you please explain issue in detail?

From which mask to which mask you are changing,?

Are you changing VLAN as well?

What would be the exact error you getting?

Thanks!

[Manu83]

Hi,

Actually I have 5 VLANS on the switch.

Out of that I am trying to change the Data VLAN from /24 to /23.

I am not changing any other settings.

Thanks.

[parnassus]

Is the 10.10.30.0/23 overlapping against - maybe - another existing VLAN subnet (potentially 10.10.31.0/24)? if it's not...why not trying to remove SVI from VLAN id 30 and assign it againt as 10.10.30.1 but with the new subnet 255.255.254.0 instead of changing it?

[akg7 · Accepted solution]

Hi @Manu83,

Overlapping is also possible, if 10.10.30.1/24 and 10.10.31.1/24 are present in the network then you can't change it to /23 but if its not then can you try to remove the IP from vlan interface (SVI) by disabling it in GUI or 'no ip address' in CLI then add again IP with mask /23. I believe it will work.

Its strange but it worked for me in LAB otherwise was getting error.

1:

2:

3:

4:

5:

6:

7:

Thanks!

[Manu83]

Thanks a lot @akg7  and @parnassus 

Finally it worked the suggested way.

First I removed the IP from VLAN and Set the IP with new Subnet.

Thanks again.

[parnassus]

Hi! glad it worked. Generally, using CLI to manage the switch makes this procedure pretty much evident (to remove a particular configuration - in this case it was the VLAN SVI - before attempting to change/modify it...especially for a command which admit to receive, as this case was, a secondary IP but it doesn't admit it overlaps with first configured).

There are other commands, take as example the one to set NTP server(s), that require us to use the same approach but they admits multiple assignments and also overlapping ones (indeed you can configure multiple NTP servers and reassign an same IP already given).

[Manu83]

Hi @parnassus,

Yes I used CLI to change the Subnet.

Thanks for the Support.

[parnassus]

That's good, it's a fact: CLI wins.