MPLS LDP over VLAN interface?

RouterOS Forwarding Protocols
1

Hi all, so I’m beginning to experiment with deploying MPLS on my network. I am running into issues. Here’s my Setup.

Tower: RB2011. Ether5 has 2 vlans on it. Ether5 is the distribution network. Vlan 110 for Mgmt of devices (AP’s, Switch) and Vlan 103 as a PTP to my office. (/30 subnet)

Office: RB750G. Ether 1, VLAN 103 has /30 address to connect back to RB2011 at tower. Running OSPF across this VLAN. Have a routed subnet in my office (No Nat).

I’m using the VLAN interface 103 to try and setup LDP. I set both sides up, they show that the correct transport path to get to the MPLS peer, but the forwarding table never populates and Local & Remote bindings stays empty. The only devices between the RB750 and RB2011 is a Ubiquiti Rocket M5, (AP) Nanobeam M5 (CPE Antenna) and a RB260GSP at the tower powering the AP’s. The Rocket and Nanobeam have had their MTU set to 1598 (Match L2MTU on the Mikrotiks). VLAN interface left at 1500. MPLS MTU on the vlan interface set to 1560.

What am I missing?

2

Did you try to use physical interface instead of VLAN for setting up LDP?

3

I can’t at this point because of how my network is structured.. I’ve talked to another engineer at a Wireless ISP and he said they do it all the time with RB3011’s using VLANS.

4

Definitely works with VLANs, I’m doing it too. Running them on CCRs and even RB750s

There must be something in between that doesn’t like the > 1500 byte packets.

5

Check MTU throughout all the devices involved.

6

LDP uses multicast, make sure that those ubiquity devices actually forward multicast packets. There were problems with multicast on those devices in the past.

7

I found that I needed to open up UDP and TCP ports 646 so that LDP packets weren’t dropped. Multicast was setup on the wireless links.

My current situation is that when I bring up LDP and MPLS; I can no longer ping past the first router hop.. I;e: After I setup MPLS between the RB750 (local side) and RB2011 (remote side) I can ping all networks attached to the RB750, and the local addresses of the RB2011, but all TCP/IP connectivity beyond that router is broken.

8

I’ve been messing around with this on and off since my last post. What I have found is once I enable LDP on both routers and the MPLS Forwarding table is populated, all TCP/IP communication between the routers breaks. I can’t ping across them, etc.

I’m at my wits end. I have the MTU of the ubiquiti devices set at 1600 and the MPLS MTU set at 1560 currently.

Any other things to check?