The basic premise behind stub areas in OSPF is that if routers want to communicate to another area they need to send packets to the Area Border Router (ABR), a router that connects OSPF areas.
So, by using a default route that points to ABRs address the routers inside an area can reach all the destinations outside their area without the need to have all the specific routes in their routing tables.
In the last blog post about different OSPF area types we noted that multiple types of OSPF areas exist. We also briefly explained each area type and why is it useful. Then we configured two of those types in GNS3: Stub areas & Totally Stubby Areas.
External Routes are not advertied into a stub area. Interarea routes are advertied.
We'll make a simple "City guide to Zagreb", meaning we'll select interesting locations from the database, display them on a map, show some info about them and show directions from user's current position to a location of his/her choice.
What you'll need
- PHP/MySQL Development Environment
- Some free time
As you can see it's really easy to get started. So, let's do it!
In this blog post we'll create a simple registration using Facebook registration plugin. We'll also create a simple login system that enables registered users to login to our site.
About Facebook Registration plugin
Facebook registration plugin enables users to register for a website regardless if they have Facebook account or not. However, if they have a Facebook account the registration form will be automatically filled with the user information from their Facebook account.
We'll create a Simple Blog Site from scratch using the eZ Publish CMS.
If you didn't come across eZ Publish yet it would be useful to familiarize yourself with both installation of eZ Publish and with first steps after an installation (post includes basics of creating a extension).
In this post I'll start with a "Plain Site" eZ Publish installation, because it's easier to explain some concepts that way, but if you already have another installation it really doesn't matter because we'll make our own design, templates and classes.
Multi Area OSPF: Backbone Area
In a blog post about Multi Area OSPF we went over some pros of having multiple OSPF areas in your network.
- Reduce the size of the routing tables. Each OSPF area can contain multiple Routers and cover a portion of a network that can be summarized.
- Reduce traffic between different parts of a network
- Reduce execution of Shortest Path First algorithm