Hi all

Running a Draytek Vigor with 4.51 firmware

My network is VLAN'ed via the Draytek router.  I've just noticed that when I untag a port on say, VLAN 2 (LAN2) the laptop gets an IP from that subnet (DHCP enabled on the Draytek) which is fine.

But when I untag the same switch port on another subnet that doesn't have a DHCP pool the device retains the same IP as it did when on VLAN 2.  Weirdly, it can communicate with devices on that newly untagged subnet.  Its like its sitting on the correct VLAN but with an IP from the previous subnet, lol.

The only way I've managed to get round this issue so far is to set the DHCP lease time on the subnet to an aggressive 10 seconds from the default 86400 seconds so the IP is forced to renew.  Otherwise the IP is retained even when on a different VLAN.

Is this how the DHCP lease is supposed to work?  Is it a bug?

Thanks all