DHCP and VLANs

From MMAE

When DHCP is used over multiple VLANs, there must be either a DHCP server or a DHCP relay agent on each vlan.

Key words:

• DHCP
• DHCP relay agent
• RFC 1542
• GIADDR field: Gateway ip address
• Scope

[edit] DHCP setup possiblities

These are possible ways to set up DHCP in the presence of VLANs. These methods are not necessarily mutually exclusive, but no more than one per vlan should be used at a time.

• One DHCP server for mutliple vlans, use a DHCP relay agent in the router. (buggy!)
• Set up a separate DHCP server dedicated to a VLAN.
• Set up a separate DHCP relay agent on each VLAN (windows server, linux, linux router on a floppy, etc.)
• Set up trunking on the DHCP server, with a trunk to each VLAN (windows max 32?)
• Set up trunking on one or more DHCP relay servers

[edit] external links

• Microsoft:
  • DHCP: Spanning Multiple Subnets
  • How to Configure Your DHCP Server Scope
  • Creating DHCP Scopes Using DHCP Manager
  • Configuring scopes
  • Activation of DHCP scopes (windows 2000)
  • Using Split-Scope Configurations (redundancy)
• Google: dhcp scope