Cisco to MikroTik – MPLS

About the Cisco to MikroTik series

One of the hardest things to do quickly in network engineering, is learn a new syntax for a NOS. Especially if you have a tight deadline and need to stand up equipment you’ve never worked with before. The command structure for RouterOS can be cumbersome if you are used to the Cisco CLI.

If you’ve been in networking for a while, you probably started with learning the Cisco CLI. Therefore, it is helpful to compare the commands if you want to implement a network with a MikroTik and Cisco routers.

This is the third post in a series that creates a Rosetta stone between IOS and RouterOS. We plan to tackle  other command comparisons like VLANs, QoS and basic operations to make it easier for network engineers trained in Cisco IOS to successfully implement Mikrotik / RouterOS devices.

Click here for the first article in this series – “Cisco to MikroTik BGP command translation”
Click here for the second article in this series – “Cisco to MikroTik OSPF command translation”

While many commands have almost the exact same information, others are as close as possible. Since there isn’t always an exact match, sometimes you may have to run two or three commands to get the information needed.

Using  EVE-NG for testing

In the last article, we began using EVE-NG instead of GNS3 to emulate both Cisco IOS and RouterOS so we could compare the different commands and ensure the translation was as close as possible. Don’t get me wrong, I like GNS3, but the web interface of EVE-NG makes it really easy to keep all the horsepower for complex labs at a central location and then VPN in to work on labs as needed.

Network for Basic mpls commands

MPLS-Cisco-to-MikroTik

Cisco commandMikroTik Command
show mpls ldp neighbormpls ldp neighbor print
show mpls interfacesmpls ldp interface print
show mpls forwarding-tablempls forwarding-table print
show mpls bindingmpls remote-bindings print
sh mpls ip binding localmpls local-bindings print
sh mpls label rangempls print
sh mpls ldp parametersmpls ldp print
interface GigabitEthernet0/1
mpls ip
/mpls ldp interface
add interface=ether1
mpls ldp router-id Loopback0/mpls ldp
set enabled=yes lsr-id=10.1.1.3

Examples of the MikroTik RouterOS commands from the table above


[admin@MikroTik] > mpls ldp neighbor print

This command will show LDP neighbors and detail on whether they are Dynamic, Targeted, Operational or using VPLS

mpls-ldp-neighbor-print

[admin@MikroTik] > mpls ldp interface print

This command will list the interfaces that LDP is enabled on

mpls-ldp-interface-print

[admin@MikroTik] > mpls forwarding-table print

Use this command to display the MPLS forwarding table which shows what labels are assigned, the interface used and the next hop.

mpls-forwarding-table-print

[admin@MikroTik] > mpls remote-bindings print

This is a quick way to show remote bindings which displays the labels desired and used by the next hop routers for each prefix.

mpls-remote-bindings-print

[admin@MikroTik] > mpls local-bindings print

This is a quick way to show local bindings which displays the labels desired and used by the local router – in this case R3.

mpls-local-bindings-print

[admin@MikroTik] > mpls print

This is a quick way to show basic mpls settings for RouterOS which includes the label range and whether or not to propagate TTL which affects what a traceroute looks like over an MPLS network.

mpls-print

[admin@MikroTik] > mpls ldp print

This is a quick way to show mpls ldp settings for Router-OS including whether or not LDP is enabled.

mpls-ldp-print

Configurations

R1

R2

R3

R4

 

 

 

WISP Design – Building Highly Available VPLS for Public Subnets

What is VPLS?

Virtual Private LAN Service or VPLS is a Layer 2 overlay or tunnel that allows for the encapsulation of ethernet frames (with or without VLAN tags) over an MPLS network.

https://tools.ietf.org/html/rfc4762

VPLS is often found in Telco networks that rely on PPPoE to create centralized BRAS deployments by bringing all of the end users to a common point via L2.

MikroTik VPLS example (https://wiki.mikrotik.com/wiki/Transparently_Bridge_two_Networks_using_MPLS)

Wlink

Background

The idea for this post came out of a working session (at the bar of course) at WISPAmerica 2018 in Birmingham, Alabama.

There was a discussion about how to create redundancy for VPLS tunnels on multiple routers. I started working on this in EVE-NG as we were talking about it.

The goal is creating highly available endpoints for VPLS when using them to deploy a public subnet that can be delivered to any tower in the WISP. The same idea works for wireline networks as well.

Use Case

As IPv4 becomes harder to get, ISPs like WISPs, without large blocks of public space find it difficult to deploy them in smaller subnets. The idea behind breaking up a /23 or /24 for example, is that every tower has public IP addresses available.

However, the problem with this approach is that some subnets may not be used if there isn’t much demand for a dedicated public IP by customers.

What makes VPLS attractive in this scenario is that the public subnet (a /24 in this example) can be placed at the data center as an intact prefix.

VPLS tunnels then allow for individual IP addresses to exist at any tower in the network which provides flexibility and conserves IPv4 space by not subnetting the block into /29 /28 /27 at the tower level.

Lab Network

VPLS

Deployment

In this lab, the VPLS tunnels terminate in two different data centers as well as at a tower router to create an L2 segment for 203.0.113.0/24. VRRP is then run between the two data center VPLS routers so that the gateway of 203.0.113.1 can failover to the other DC if needed.

Failover

Here is an example of the convergence time when we manually fail R1 and the gateway flips over to R2 in the other DC. The yellow highlight marks the point where R1 has failed and R2 VRRP has become master.

vpls-failover

Configurations

R1-vpls-agg

R2-vpls-agg

R3-Tower-1