moving a subnet to a different fabric prevents DHCP relay configuration

[Peter Jose De Sousa]

Hello,

When configuring DHCP relay on MAAS, if a relay is configured on a VLAN, for example VLAN 41, with a subnet, for example 10.10.21.0/24. If that subnet is then moved to a different fabric, its not possible to disable the relay. The following warning is shown on the MAAS UI:

"No subnets are available on this VLAN. DHCP cannot be enabled." Although the UI shows as DHCP enabled.

[Steps to reproduce]
1. Setup maas with two VLANs, one untagged, one native VLAN for example VID 41, the native VLAN having DHCP forwarded to the untagged VLAN.
2. Setup a DHCP relay to go from 41, to untagged.
3. Configure DHCP relay for VLAN 41 via untagged along with a dynamic range.
4. Create a new fabric, and move the subnet for VLAN 41 to this subnet.
5. Try to disable DHCP relay on VLAN 41.

[Workaround]

Move the subnet back to its original VLAN, and disable DHCP first.

Thanks,
Peter

[Alexsander de Souza (alexsander-souza)]

This limitation exists only in the UI, it's possible to remove the DHCP relay settings using the CLI:

maas $ADMIN vlan update $FABRIC_ID $VID relay_vlan=

[Thorsten Merten (thorsten-merten)]

need to test whether this is a problem of MAAS UI or a problem in the websocket API