wansolutions
Technical User
My network consists of Cisco 6500 core switches, Cisco 3750 access switches, Windows XP Pro desktops and Windows 2003 AD domain controllers.
Workstations being moved from one VLAN to another are not able to connect to the LAN because they are being reissued their old (from the first VLAN they connect on) IP address via DHCP.
This is occurring even when IP’s are being released from the workstation and after the host machines have been re-imaged.
Please note that the DHCP servers that are defined in the ip-helper statements of the VLANs are the same, ie: VLAN 10 & 20 are both configured with 10.1.1.1/24 and 10.1.1.2/24 (in that order).
I have performed packet captures with in the environment and all appears to be working correctly on the switch side of things, offers to workstations are being handled by the VLAN gateway and the "ip-helper" statements correctly define the new DHCP servers.
Before the new servers were installed, VLAN's 10 and 20 were served DHCP from the old servers 10.1.1.3/24 and 10.1.1.4/24, without hiccup. Core layer 3 switch was then configure with these addresses as the "ip-helper" for these VLAN's.
The old servers were Windows 2000.
I think that there must be checkbox, or similar, that is enabled by default (for security or administrative ease) that has the new 2003 AD servers remember the MAC address of the workstations requesting a dynamic address, and thus reassigns the first address that was initially assigned to that machine.
If a host is first connected to the network in VLAN 10, then removed and re-imaged and connected to VLAN 20, that workstation is getting the address it was first assigned from VLAN 10.
Thanks in advance.
Cheers, Kirby.
Workstations being moved from one VLAN to another are not able to connect to the LAN because they are being reissued their old (from the first VLAN they connect on) IP address via DHCP.
This is occurring even when IP’s are being released from the workstation and after the host machines have been re-imaged.
Please note that the DHCP servers that are defined in the ip-helper statements of the VLANs are the same, ie: VLAN 10 & 20 are both configured with 10.1.1.1/24 and 10.1.1.2/24 (in that order).
I have performed packet captures with in the environment and all appears to be working correctly on the switch side of things, offers to workstations are being handled by the VLAN gateway and the "ip-helper" statements correctly define the new DHCP servers.
Before the new servers were installed, VLAN's 10 and 20 were served DHCP from the old servers 10.1.1.3/24 and 10.1.1.4/24, without hiccup. Core layer 3 switch was then configure with these addresses as the "ip-helper" for these VLAN's.
The old servers were Windows 2000.
I think that there must be checkbox, or similar, that is enabled by default (for security or administrative ease) that has the new 2003 AD servers remember the MAC address of the workstations requesting a dynamic address, and thus reassigns the first address that was initially assigned to that machine.
If a host is first connected to the network in VLAN 10, then removed and re-imaged and connected to VLAN 20, that workstation is getting the address it was first assigned from VLAN 10.
Thanks in advance.
Cheers, Kirby.
