Multiple VLANs one DHCP one NIC. 2

[CiCiNL]

Customer wants the following sollution:
DHCP server in Vlan 1.
When DHCP request is received with VLAN tag 10, it is relayed to the DHCP server and an IP@ is assigned from the scope reserved fro vlan 10.

Can anyone explain to me which DHCP options I have to assign to the scope, to asiign the IP@ based on Vlan ID/tag?

 

[chipk]

None. Just create the scope with the desired address range, subnet mask, and default gateway. As long as your hosts are assigned to that particular vlan at the switch level, and that vlan is configured on the router correctly, DHCP will assign the correct address.

You may need "helper address" configured on the router or layer3 switch so that it knows to allow those broadcasts to go to the DHCP server.

 

[CiCiNL]

The data vlan is default vlan 1 - ip range 10.1.1.0
The voice vlan is vlan 10 - ip range 10.1.10.0
DHCP server is in vlan 1.
DHCP relay (ip helper address) is set on the switch to forward DHCP request from vlan 10 to vlan 1.
When a request is received by the DHCP server from Vlan 10 he has to assign a vlan 10 ip-address.
How can the server engineer tell his DHCP server to do so?

 

[WhoKilledKenny]

In DHCP you will create two scopes.
VLAN1 10.1.1.0\24 (assuming your SM)
VLAN10 10.1.10.0\24

The DHCP Clients will broadcast (Uni-cast or Multi-cast) a discover packet. Depending on the type of broacast the DCHP server will know if it's local (on same subnet) or from another VLAN. If from another vlan the packet would have the subnet info from where the broacast came from. That is how DHCP will know which Scope to use to assign proper ip for the VLAN.

 

[CiCiNL]

Thank you both for clarifying this.