Hi Alex, The configuration depends on your network design. If the CCR is acting purely as a router, there is no need for it to be involved in Spanning Tree at all, as there is no chance of it causing a loop regardless of whether you use LACP or not. If you use bridges with multiple interfaces attached, then you would probably want spanning tree configured appropriately. That said, it sounds like having portfast disabled on your switches so you have that MAC learning time delaying connectivity might prevent OSPF flaps if the CCR keeps rebooting within the learning window, at the cost of additional delay in network reconvergence if you intentionally reboot a device. We use LACP a lot with our CCRs, including in an MLAG configuration. However instead of Spanning Tree, we use other technologies similar to ERPS (https://en.wikipedia.org/wiki/Ethernet_Ring_Protection_Switching) that suit our needs better, but our environment might be more controlled than yours. Regards, Philip Loenneker | Network Engineer | TasmaNet 40-50 Innovation Drive, Dowsing Point, Tas 7010, Australia P: 03 6165 2542 | M: 0404 097 816 philip.loenneker@tasmanet.com.au www.tasmanet.com.au -----Original Message----- From: Public [mailto:public-bounces@talk.mikrotik.com.au] On Behalf Of Alex Samad - Yieldbroker Sent: Friday, 2 December 2016 9:24 AM To: public@talk.mikrotik.com.au Subject: [MT-AU Public] ccr connections to switches Hi I have 6 ccr1036's in pairs of 2 LACP'ed to stacked Dell 8024F & 8132F switches.. These are about to be replaced with arista 7050sx switches in MLAG config. I have previously setup the CCr1036 as STP edge devices, so portfast and spanning tree disabled. But I have recently had 2 ccr's do death reboot cycles, crash and then reboot themselves in loops. This has cause lots of problems for my OSPF network :) I presume they have DR or BR at the times - unlucky me. I notice I with LACP there is RSTP turned on. Which got me thinking maybe I should have them configured on the switches as No portfast No span disabled And make them go through a spanning tree block , learn, forward states. Just wonder how others have their ccr's connection - especially if you have LACP connection Alex _______________________________________________ Public mailing list Public@talk.mikrotik.com.au http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.com.au