Hi, sorry not sure what you mean by that. Do you mean physical ports?

yes, are they linked via the LAN or the WAN ports

Yes there is a direct cable going from draytek 1 LAN port into draytek 2 LAN port (no switches hubs in between)

that is likey to cause some issue then as you would now have two DHCP servers on one phyical network so the PCs on the 128xxx network could get a 192xxx address and vice versa - unless its all static

Hi sicon, thanks very much for your help. I've managed to get it working now and this was the procedure (with help from Harry @ Draytek support) ...

1. I enabled VLANS on my 2860 router and for vlan0 i ticked the ports P1, P2, P3, P4 and P5. In vlan1 i put a tick in the P6 box. (Because I planned to physically wire my older 2600 draytek into port 6 on the new draytek.
2. for vlan0 I chose a subnet of LAN1 and for vlan1 I selected LAN2. I was warned not tick/enable VLAN tag.
3. I then went into the LAN/General setup page and clicked on the details page for LAN2. I disabled the DHCP server and changed the ip address to 192.168.12.100 (which is the static route address that was entered in my 2600 router)
4. Lastly I clicked on the LAN General Setup Page and enabled LAN2 then in the bottom Inter-Lan routing section I put a tick in the box that cross-referenced both LAN1 and LAN2
5. Lastly I remembered to put the cable from the 2600 directly into Port 6 of the 2860 router.

Hope that helps someone in future..

Regards,
John

that was going to be my next suggestion - Enable VLANS , glad you got it working