When using different brands of router in your network, you need to know how to share your network routes within that same network.
This article aims to make it a bit clearer how Peplink routers share their network routes with neighbouring routers.
How do Peplink routers share information about their known routes?
Routers are intelligent networking devices that forward data packets between computer networks.
They maintain network data which contains information such as routes, nodes, and network addresses. Using this information, they direct the network data to the next network or destination on its journey. You could say that routers are the traffic directors of the digital world.
Route advertising
The purpose of route advertising is to share available routes that exist on the enterprise network, with other routers to enable to make routing decisions.
Routing protocols enable the collection of neighbouring router information, which is then advertised for all other nodes via the network.
Routing Protocols
Peplink routers supports several routing protocols; OSPF, RIPv2 and BGP.
OSPF and RIPv2 are both interior gateway protocols, which allow you to exchange routing with other routers in the same network.
Support for BGP is more recent. BGP is an exterior gateway protocol, which allows for the exchange of routing and reach-ability information between routing domains on the Internet (but can also be used for sharing of internal routes).
BGP was introduced in firmware 7.1.1 and new BGP features have been added since.
Routing Tables
When routers share routing information the data is stored in the routing table.
A routing table is a set of rules, that is used to determine where data packets traveling over an Internet Protocol (IP) network will be directed. All IP-enabled devices, including routers and switches, use routing tables.
If you have a Windows computer, open up an administrative prompt and type
route print -4 You’ll see the routing table of your computer.
It will show you subnets and tell you to which network interface traffic destined for one of these subnets, will be sent.
What about the routing table for Peplink routers?
Peplink routers use dynamic routing, which gives the routers the ability to adapt to logical network topology changes, equipment failures or network outages automatically and on the fly.
Routing tables are massively complex in a multi-WAN dynamic outbound policy based routing environment. Up until today (firmware 8.1) it is not possible to view the full routing table on Peplink routers. Possibly because there is no way to show that rapidly changing information in a useful way.
That’s interesting, but weren’t you going to tell us how Peplink routers share information about their known routes?
Correct, let’s have a look at the route sharing options in Peplink routers and how Peplink routers can be integrated in existing networks with third party routers.
We’ll do do this by configuring route sharing between 2 Peplink routers and 2 Ubiquity routers in our test lab.
We suggest you configure this in your own test lab to help you understand what is happening at each stage.
Practice Test lab
A (ficticious) company wants to start using SD-WAN but is not ready to change their existing network infrastructure.
The customer would like to keep their existing Edge routers and does not want to change the existing IP addressing.
Typically, the existing routers are connected by IPsec VPN to allow LAN clients in the local and remote site to securely communicate.
The network configuration would be similar as shown below.
Clients on the local and remote VLANs would be able to share data over the IPsec VPN.
Routes with be advertised over the IPsec VPN tunnel.
In this situation you can add Peplink routers on the WAN side of the existing, third party routers to allow for multiple WAN connections and share any existing routes with OSPF and / or BGP.
You’ll end up with the following configuration shown in the image below.
Peplink routers will be added to the WAN side of the existing edge routers.
A Speedfusion VPN between the two Peplink routers will replace the IPsec VPN.
Route advertising between the network will be configured using OSPF and BGP (because we want to show you both options).
Step 1
We leave the current network intact and will install Peplink routers in the local and remote site with their own WAN connections (cellular, satellite or wired).
The 2 routers will act as standalone routers and are not aware of each other’s routes (also called networks, or VLANs, or subnets).
If you check the status page of each of the Peplink routers you’ll see that there is no known information about any remote networks.
Step 2
Create a PepVPN / Speedfusion connection between the 2 Peplink routers (A & B).
When you have configured and enabled this, you’ll see on the dashboard page that the routers will start to update their routes on the dashboard before the VPN tunnel is established.
Now have a look at the OSPF status page of the remote router; you’ll see that the LAN of the router in the local site (192.168.2.0/24) has become a known route.
This is because the local LAN and VLANs are advertised to the PepVPN/ Speedfusion interface by default.
You can verify this by looking at the OSPF &RIPv2 page, which you can find in the menu under “Network” or “advanced” depending on the Peplink model you are using.
You’ll find multiple settings in this section, which is too much to discuss in this article , but if you look in the Peplink user manual or hover over the question marks you’ll see an explanation for the available options.
Step 3
Next, connect the third-party router (D) to a LAN port of the Peplink router in the remote site (router B). Router D is configured with IP address 192.168.5.2 and 2 VLANs.
Network 10.77.1.0/24 (VLAN ID 77) and network 10.66.1.0/24 (VLAN ID 66).
Because traffic to and from Router D is NAT-ed Peplink router B is not aware of VLAN 66 and 77.
By advertising OSPF Area ID 0.0.0.0 to the LAN interface we can share the networks from router D to router B, as long as the same OSPF Area ID (Area ID 0.0.0.0) is configured on router D.
OSPF settings on Ubiquiti router D
Check the OSPF status again on Router B and you should see the networks from Router D!
Check the OSPF status on Router A and you’ll see that Router D has shared it routes to network Peplink Router B, which has shared its routes to Router A. All by using OSPF.
Step 4
We now know how you can share routes using OSPF. We’ll connect Router C to the LAN of Peplink Router A and we’ll share the routes on Router C to the rest of the network using BGP.
In this example we’ll be using eBGP (not iBGP). There is a lot more to learn about BGP.
All you need to know for this configuration is that you will be assigning a different ASN (Autonomous System Number) to each router.
For the Peplink router A we configure a BGP profile with the following settings:
- Connected interface: untagged LAN (192.168.5.1/24)
- ASN: 65101
- Neighbor: 192.168.2.2 (the WAN IP address of Router C) and 65100 (the ASN we’ll assign to router C).
The third-party router should have its own BGP profile with AN 65100 and neighbor settings: 192.168.2.1 with ASN 65101.
When these settings are saved an applied check the BGP status and you’ll see the routes that are imported and exported using BGP
Finally, make sure that static route advertising is enabled on Router A.
Thai will make sure that the routes from Third party router C that are shared to Peplink router A will also be shared over Speedfusion to the remote location.
Conclusion
This Test Case example shows how you can use OSPF or BGP to share routes between routers from different brands within a network.
Route advertising can be configured in many different ways, there are a lot more options that can be used to make sure that IP- enabled devices have access to different parts of the network.
As always, the best way to learn is by trial and error and make sure you test your configuration before you configure your production environment!
