Hi All,

Upgraded an RB450G from 5.5 and 5.7 and it seems the Vlans I had configured on a network bridge (2 ports) stopped working correctly.

Downgraded from 5.7 to 5.6 and traffic on the Vlans started working again.

I'm not 100% sure if it's all traffic on the Vlan or just broadcast traffic as none of the clients were able to get a DHCP address (RB has DHCP servers configured for some of these vlans and others use an external DHCP, neither worked)

Had tried rebooting/re-assigning the vlans to another port and back to the bridge before downgrading and none of that worked.

Edit:

Raised a ticket with MT as I think it might be a bug

there is a known problem with DHCP server. It will be resovled in RouterOS 5.8

there is a known problem with DHCP server. It will be resovled in RouterOS 5.8

Hi Janisk,

I don't think this is just the DHCP server though as some of the VLans had an external DHCP server and still had no DHCP

Edit: Forgot the DHCP relay is being used for those other vlans,

Is this bug specific to the RB4xxx or is it a generic routerOS bug affecting multiple archs? (Asking as i also have an RB1200 that will be using DHCP on vlans so wondering if i'll also need to downgrade that to 5.6)