In a VLAN environment, how does a DHCP client know which VLAN to choose to send a DISCOVER packet?

Hi all,

We have a VLAN environment, where nodes (actually base stations in telco) are connected to switches/routers tagged with a certain VLANs. We need to configure these nodes as DHCP clients and install a global DHCP server for many such subnets. We will create separate scopes for each subnet in DHCP server config file.

Question is,

1. When the DHCP client boots up, how will it know which VLAN to pick up to send it's DHCP Discover packets? I mean, let's say according to network topology, this client's packets need to be tagged with VLAN 10. As we are using DHCP, so immediately after boot-up how will it know to use VLAN 10 to send it's Discover packets?
2. And in the DHCP Offer or DHCP ACK packet, does the DHCP server include any VLAN information for the client to use for subsequent packet transfer?

I think I read somewhere (can't remember the source) that it will first send untagged packet and then keep sending tagged packets with every VLAN by incrementing VLAN ID. Is it a general procedure or is this followed in client equipment by certain vendors?

Thanks in advance. Cheers !!