Question about LACP and bonding

RouterOS General
1

Hi all,

I have a CRS and three switches DLNK: two for users and the last one for other LAN services. I created three bonding interfaces (mode 802.3ad) with two link for each switch, then I created a bridge with the three bonding interfaces to manage the VLANs. This configuration may be cause problems? I need allow STP in the CRS and the switches?

Thanks for all.

2

STP is originally designed as a protection against L2 loops caused by incorrect cabling, and it does make sense to use it for this purpose even though you use bonding for redundancy. Just check whether the STP flavors are compatible between the Mikrotik and the D-Links, in general, MSTP is the most universally compatible one.

3

I thought RSTP was the most common one?

4

Most common indeed; most compatible not necessarily. E.g. on Cisco switches, it is not possible to enable VLAN-agnostic RSTP per se, it is only available as a fallback mode of MSTP (RSTP is used where the neighboring bridges are in different regions):

STACK-C9200(config)#spanning-tree mode ?
  mst         Multiple spanning tree mode
  pvst        Per-Vlan spanning tree mode
  rapid-pvst  Per-Vlan rapid spanning tree mode
5

I don’t have loop for redundancy and shouldn’t had loop in the cabling, or I expect so… D-Link support RSTP and MSTP but I think It dosen’t necesary.

We have client’s disconnections of the WiFi that It’s managed by CAPsMANv2 in two cAP ax devices, I’ll describe in another post. My first doubt was if the LACP inside the bridge may cause problems or loops, but if it’s correct the problem should be other.

Thanks for all.

6

The point of protection against loops is that even if you don’t “misuse” STP as a redundancy protocol, someone may “connect a loose cable” and create a loop by mistake. In a certain country the network in the parliament was down for several hours due to some passer-by who saw a loose end of a cable next to an empty socket and decided to “fix” it.

7

Hey, enable STP on both the CRS and switches to avoid loops. Just set the priorities so the CRS is the root if needed.

8

I lived a similar issued in my last job. I known this problem exists but It’s a new instalation with 10-12 interfaces occupied, including bonding, and the clients are mostly wireless.

I’ll configure STP in the devices, for security especially, but I think the problem It’s in other side. This devices were configuring and tested before I installed. In lab, all worked fine, but now I have a odd behaviour, Today I cretaed a “similar” lab to try to replicate the problems, As I said, the real scenario include two cAP ax that are connected to the third switch. All devices are managed by us with no defaults passwords and all configurations were made for us.

I will try allowing STP into devices and I’ll comment the results.

Thanks for all.

Edit: The title of the post is wrong and now I notice… Please, could someone admin change It to “Question about LACP and Bridges” or “Question about Bonding and Bridges”. Thanks.