Configuring a single subnet across multiple VLANs

[ally.wong]

Hi

I need to deploy a new network (the subnet will used will be the same as the existing subnet). At this stage I cannot change the existing network in place. It is currently using VLAN 1. The new core switches I will be deploying will use multiple VLANs, however the main VLAN for management, for example will be VLAN 100.

I have current equipment which is not cisco and are unmanaged. I do NOT at this stage want to rebuild the "now legacy network" with the new network management VLAN. The Legacy network will be designed and built at a later date.

Both VLAN 1 and VLAN 100 say for example will use network address 192.168.50.1 as the gateway address with network range 192.168.50.0/24

Is there a way to define VLAN 1 and VLAN 100 with the same ip address ?

or would it be better to do the following

VLAN 1

IP address 192.168.50.1/24

VLAN 100

IP address 192.168.50.2/24

IP address 192.168.50.1/24 secondary ?

Is this type of configuration supported on cisco ?. Inclusive of having the same subnet in VLAN 1 and VLAN 100 ?

I know on the Brocade switches it is

W

[smitesh kharecha]

Hi Ally,

Remove the IP address on VLAN 1 and make a new loopback interface. Give the IP of VLAN 1 to that new loopback interface and then on both VLAN 1 and VLAN 100, you can use the same IP address, as ip unnumbered loopback X.

HTH,

Smitesh

[ally.wong]

Hi Smitesh

Thats fantastic I never thought of that

Many thanks for your assistance, its greatly appreciated

Kind Regards

Ally

[smitesh kharecha]

Hi Ally,

Please mark the thread as answered if you think it has been solved your query, so that other community members doesn't have to come to this thread and find it already to be answered.

Thanks

Smitesh

[ally.wong]

Hi Smitesh

Will do you saved me many hours of work and headaches

Kind Regards

Ally Wilson