You are on page 1of 20

Powercode Documentation – OSPF Network Tutorial

Powercode OSPF Tutorial
The purpose of this document is to provide a guide to the correct method of integrating Powercode into an OSPF network. For the purpose of this document, I will be using the Mikrotik 450G for configuration examples but this document is applicable to any OSPF capable router.

Routing Protocol Overview
For those of you already familiar with routing protocols, you can skip this section.

What is a routing protocol?
A routing protocol is a protocol that specifies how routers communicate with each other, disseminating information that enables them to select routes.

Each router has a prior knowledge only of networks attached to it directly. A routing protocol shares this information first among immediate neighbors, and then throughout the network. This way, routers gain knowledge of the topology of the network.

What is OSPF?
Open Shortest Path First (OSPF) is an adaptive routing protocol for IP networks. It uses a link state routing algorithm and falls into the group of interior routing protocols, operating within a single autonomous system. The basic concept of link-state routing is that every node constructs a map of the connectivity to the network, in the form of a graph, showing which nodes are connected to which other nodes. Each node then independently calculates the next best logical path from it to every possible destination in the network. The collection of best paths will then form the node's routing table.

What does this mean to you?
This means that you can add a new subnet to any OSPF enabled router in the network and every other router in the entire network will know three things: 1. That this subnet exists on the network 2. The best route to this subnet on the network

Powercode Documentation – OSPF Network Tutorial 3. All other routes to this subnet on the network This also means that, as long as there is another path to this subnet available on the network, you can have a transport failure with minimal service interruption to the customers served by that subnet and without any additional work on your part. If you read the previous Powercode routed network tutorial you may have thought ‘static routes are great but what happens when you have more than a couple of routers in your network?’ The answer is a routing protocol and the one I will focus on in this document is OSPF.

Why pick OSPF?
There are a couple of major reasons to select OSPF over other routing protocols – availability in a wide range of routers and ease of configuration. For a basic configuration, OSPF is one of the easier protocols to configure and as it is an open standard, most routers support it. So, all that being said, let’s take a look at a good OSPF candidate network.

How will OSPF determine the path to take in this network? OSPF uses path cost as its basic routing metric. Our solution to this conundrum is to implement a routing protocol and our choice will be OSPF.Powercode Documentation – OSPF Network Tutorial This type of network is a prime candidate to be a routed network. In practice. you would have an even larger challenge on your hands. . if you moved to a routed network and tried to configure this network using just static routes. you would have a potential nightmare on your hands with spanning tree. If this network was Layer 2. a 10Mbps link may have a cost of 10 and a 100Mbps link may have a cost of 1. On the other hand. ARP traffic and other Layer 2 issues. For example. most routers will look at the interface speed to determine the local cost on the router.

it does make some things more difficult. For example. However. You will no longer be able to send out network wide broadcasts and you will no longer be able to see the MAC address of a customer that is behind a remote router. As long as the router you use supports standard OSPF. not transport speed. it will work.Powercode Documentation – OSPF Network Tutorial Bear in mind that this is interface speed. 1. routed OSPF setup is not terribly difficult to configure and learn. etc. You can manipulate this calculation by applying a fixed cost to a particular interface. equipment management. from a network design perspective – it stops people being able to do ARP poisoning across your whole network. 3. This means you will probably want to configure all links between routers with public IP addresses. If you have a backhaul that can only pass 5Mbps but the physical interface on it is a 100Mbps interface. We have tested OSPF on the BMU MAXX with Mikrotik. you can generally assume that OSPF will calculate the best path to take by hop count. . Imagestream and Cisco. What routers should I use? Whatever you want! OSPF is not a proprietary protocol. Customers will be able to see all your hops on a traceroute. you will no longer be able to use ‘Match MAC & IP’ in Powercode unless you have a BMU at each tower. a few things should be considered. You can no longer route large subnets across your entire network – each router will need to have a unique subnet for customers. assuming all interface speeds are equal. This is a good thing.000 Cisco 7600 – it’s up to you! The biggest obstacle will probably be the learning curve if you are not already familiar with the concepts we’re discussing but a basic. Considerations before migrating from Layer 2 to Layer 3 Before moving to any routed network. We will address this specifically in a later section but it is important to be aware of the method by which a router will determine the direction to send a packet. 2. The Mikrotik 450G will handle most smaller towers at a low cost (~$200) or you can go with a $250. In practice. it cuts down on ARP traffic and more. the router will calculate this as a 100Mbps interface for path cost calculation. as the BMU will no longer be able to see the MAC of the customer.

Here is our example network. network uplink interfaces. We’ll look at this in a second. This kind of configuration can scale to a much larger setup without any changes.Powercode Documentation – OSPF Network Tutorial Powercode Considerations One additional step for Powercode is that you will need to add every router interface to Infrastructure. . All subnets that you are doing DHCP relay for in the BMU need to be added to a Shared Network. Let’s take a look at a real configuration step by step for a simple. small ring. This means your customer facing interfaces. management interfaces – everything! You will also need to set all the remote routers to DHCP relay to the BMU.

0.0/24 172.16. we need to create a management IP for each tower router.8/30 10.Powercode Documentation – OSPF Network Tutorial The first thing we need to determine is an IP addressing scheme that we want to use on this network.0.0/24 192.0/24 192.2.0.3. Tower 1 Customer Space Tower 2 Customer Space Tower 3 Customer Space Tower 4 Customer Space 192. Tower 1 to Tower 2 Tower 2 to Tower 3 Tower 3 to Tower 4 Tower 4 to BMU BMU to Tower 1 10.168. as mentioned earlier.1.0.0/30 10.0/24 Now we need space for uplinks between the routers.12/30 10.2. First.3.1.168. I would strongly suggest using public IP addresses for the links between the routers.0. Tower 1 Equipment Management Tower 2 Equipment Management Tower 3 Equipment Management Tower 4 Equipment Management 172.0/24 172. For the purpose of this tutorial. tower equipment. we will use private IP addresses for everything but.0. let’s determine customer IP space that we want to use at each tower. a UPS or whatever other gear you have. This space could be used to assign to CPE.0/24 192. We need a management IP on these routers because you don’t want to rely on an interface address to access the .4/30 10.0/24 172.4.16.16.168.0.0.0.16.0/24 Now let’s add some space that we want to use to manage equipment at the tower.0.0.16/30 Finally.168. Each interface on the router that faces another router will need an IP address on it.

16.0. Let’s determine the subnets we need for this router.255. This means we need to add Tower 1 Customers and Tower 1 Equipment subnets to Powercode. We want to bring the whole network back into a single port on the BMU. For now.0.0/30 subnet and that interface is down. you won’t be able to access the router. By adding a management address on a virtual interface. Tower 1 Customers Tower 1 Equipment Tower 1 to Tower 2 Tower 1 to BMU Tower 1 Management 192.1/32 First. We will only need to add subnets to the Powercode BMU that will be used to address equipment managed in Powercode. Before we configure any of the subnets. just be aware we want to configure one. configuration can begin. The shared interface allows us to assign multiple DHCP subnets to an interface when we are using DHCP relay.168.0.0/24 10. if you try to telnet into the Tower 1 router on the 10.16/30 192.255.0/30 10. we need to create a shared interface in Powercode.1/32 192.2/32 192.255.168. I will show the Powercode configuration that is needed for this router. we can use a /32 subnet.0/24 172.Powercode Documentation – OSPF Network Tutorial router in case it goes down.0.255.0. If you don’t assign the subnets to the shared interface. you will have problems with DHCP relay from your tower routers. Since this is a virtual interface.4/32 Now that all the subnets for these routers have been determined. we can ensure we can get into the router through any active interface regardless of the status of the other interfaces.0. I will step through the configuration of the Tower 1 router in this document.0.3/32 192. Eth 1 will be the port we select but you can use any port you like.168.1.168.168. For example. .255. I’ll cover the configuration of this management interface later in the document.168. Tower 1 Management Tower 2 Management Tower 3 Management Tower 4 Management 192.

OSPF. .Powercode Documentation – OSPF Network Tutorial You only need one shared interface per physical interf interface. This means the subnet will not be created locally on the BMU but will be made available for DHCP and equipment addressing. Under the BMU. There are three things we need to do here that are slightly different than creating a Local Subnet. 1. Now let’s create our subnets. ace. click Add under Shared Network and create a shared interface named ETH1_Shared. Set the Type of Subnet bnet to Remote Remote-OSPF.

This includes uplinks between routers.1) The IP address that connects from Tower 1 to the equipment (172. Make sure you select Use NAT for Routing and set to Yes if this is a private address you are giving to a customer. This is not really important for typ type Remote-OSPF OSPF as we are not creating static routes – I would recommend entering the management IP of the router here for tracking purposes. Rebuild your BMU once all the subnets and DHCP ranges are added.16. Set the Shared Network to the network we previously created – ETH1_Shared.168.1. So. Once you are done creating the subnets. All router interfaces need to be added to Infrastructure. for Tower 1. Once you have completed the subnet setup in Powercode there is one final step to be completed.0. interfaces customers connect to.Powercode Documentation – OSPF Network Tutorial 2. 3. The IP Address field should be set to the next hop address for this subnet. In our example. we need to create DHCP ranges for any IPs that will be given out. interfaces that equipment is connected to – everything. we would need eed to add: The IP address that connects from Tower 1 to the customers (192. we only really need DHCP for the customer range but you may m want to use DHCP for your tower equipment as well.1) .

0.0.0. select the interface this router is connected to.0.0.255. Since we won’t see the MAC address for these e packets on the BMU (as MAC addresses are not transmitted across a Layer3 network) we need to use the global match MAC. go to Routing and then OSPF Configuration.1) Enter a descriptive name for the interface in the Equipment Name field.1) The IP address from Tower 1 to the BMU (10.0.1 (10. Enter the MAC address as 00:00:00:00:00:0A – this is a global matching MAC address.Powercode Documentation – OSPF Network Tutorial The IP address from Tower 1 to Tower 2 (10. BMU Configuration In the BMU web interface. . For Type of IP.17) The management address on Tower 1 (192.168. Once you have added all the interfaces to Infrastructure you are done ne with the Powercode configuration.

For your BMU. Open the Eth 1 interface and uncheck the Passive checkbox. Since the BMU currently only supports OSPF. Now click Update OSPF Configuration. The Router ID is a unique identifier for the router that is used to identify it through the network to other OSPF routers. We also need to set our network facing interface to an Active interface. we do want to advertise a default route into our OSPF network so check Default und under Route Redistribution. I use the management address of the router as the Router ID. Route Redistribution is used to re redistribute distribute routes from other protocols or tables back into OSPF.Powercode Documentation – OSPF Network Tutorial You need to configure a few options in here prior to configuring the rest of the network. we don’t have any other protocols to redistribute from. This means that these interfaces are not allowed to form OSPF peering sessions with other router routers. I would use your WAN IP. . Generally. However. The BMU defaults to setting all OSPF interfaces to Passive.

The only subnets we need to advertise from the BMU are: 1.0. A default route. the BMU will not advertise any networks into OSPF unless you have set route redistribution for a specific network or you have entered it into the network advertisement section. We are already ready advertising the default route by selecting Default under Route Redistribution. we will be putting every router into the backbone area. Let’s add our Tower 1 to BMU subnet (10. The Tower 1 to BMU subnet. Your main OSPF area is 0.0. Router Configuration . By default.16/30) The Area input field allows you to select the OSPF area you want to advertise into. We’re now done with the BMU configuration – let’s move onto the Tower 1 router. 2.0.0.0.0 and click Add Network. Multiple OSPF areas is outside the scope of this document – for this tutorial.0.Powercode Documentation – OSPF Network Tutorial The final thing we need to do is enter the networks we want to advertise into OSPF. 3. The Tower 4 to BMU subnet. I’m using a Mikrotik 450G for this configuration example but you can use any OSPF capable router. Le Leave ave the area at 0.0.

We need to determine the interfaces we are going to configure our IPs onto so let’s configure as follows: Ether 1 Ether 2 Ether 5 Tower 1 to BMU Tower 1 to Tower 2 Customer DHCP and Equipment Mgmt . Click on IP and then Addresses.Powercode Documentation – OSPF Network Tutorial Here we are logged into Winbox. Let’s configure our IPs.

Powercode Documentation – OSPF Network Tutorial Go through and add all your subnets to the router. . Click on Bridge and then click on +. We also need to add the management address to a virtual interface so let’s create that now.

Powercode Documentation – OSPF Network Tutorial Create a bridge interface named Management. Now let’s configure OSPF. Now go back to the IP P Addresses section and add our management IP to the Management interface. Click on Routing and then OSPF. .

To match my recommended ecommended configuration. Now click on the Interfaces tab. All you really need to do in this section is change your Router outer ID – I recommend setting it to the management address. The Mikrotik default is to have all interfaces active for OSPF. let’s set all the interfaces to passive by default. . everything else can be left to the defaults. For the purposes of our configuration.Powercode Documentation – OSPF Network Tutorial Click on the Instances tab to configure your OSPF instance. Click the + and set the Interface to All and then check the Passive box.

Powercode Documentation – OSPF Network Tutorial Now we need to explicitly set to active all the interfaces we will actually be running OSPF on. . Leave all the other options at their default settings. Go ahead ead and add both Ether 1 and Ether 2 as active OSPF interfaces.

. Click on the Networks tab and click the +.Powercode Documentation – OSPF Network Tutorial Now we need to add the networks that we will be advertising from this router.

Once everything is setup and functioning. click on IP and then DHCP Relay. You can also verify if the routes are being advertised correctly by checking the routing table.Powercode Documentation – OSPF Network Tutorial Enter every subnet that exists on the router. To set this up. Now connect this router to your BMU. To do this on the BMU. . it will not be advertised into the e network and other routers will not know the correct path to take to reach an IP in that subnet. If you fail to enter a subnet. Click on the + and then enter the appropriate information. You can verify if the OSPF adjacency is formed by clicking on the Neighbors tab under Routing->OSPF on the Mikrotik or clicking on OSPF Neighbors under Routing on the BMU. the final step we need to take is to setup DHCP Relay. Select the interface that you need to run DHCP P on and then enter the IP of the BMU. click on Routing and then Routing Table.

Powercode Documentation – OSPF Network Tutorial Now plug your laptop into Ether 5. You should then be able to pull an appropriate IP address via DHCP from the BMU and get online. . enter the MAC address of your laptop into Powercode and assign an IP from the appropriate subnet.