Cisco just announced their certification program is getting a MAJOR update. Here’s what you need to know:
This post is the 6th and final in a series of Border Gateway Protocol (BGP) posts. If you missed any of the first five parts, here are the links:
In this post, we're going to take a look at how we can work with BGP in IPv6.
You will recall from this chapter that BGP was constructed to support many different protocols and NLRI right out from its creation. As a result, we have robust support for such technologies as IPV6, MPLS VPNs, and more.
You will also relish in the fact that once you master the basics of BGP that we have covered in this , working with BGP in IPv6 is much more similar than it is different!
BGP is so remarkably flexible, as discussed earlier in this chapter, you can use IPv4 as the “carrier” protocol for IPv6...
This post is the 5th in a series of Border Gateway Protocol (BGP) posts. If you missed any of the first four, here are the links:
In this post, we're going to take a look at BGP scalability mechanisms and related concepts.
Just as IP address depletion has been a concern with the Internet, so has the depletion of available autonomous system numbers. To help solve this, the engineers turned to a familiar solution. They marked an AS number range as private-use only. This permits you to experiment with AS construction and policy in a lab (for example) and use AS numbers that are guaranteed not to conflict with Internet-based systems.
Remember, the AS number is a 16-bit number permitting up to 65,536 AS numbers. The private space is marked as 64512-65535.
This post is the 4th in a series of Border Gateway Protocol (BGP) posts. If you missed any of the first three, here are the links:
In this post, we're going to take a look at configuring BGP to advertise Network Layer Reachability Information (NLRI), and also the configuration of a BGP routing policy.
Before we even begin advertising NLRI using our various commands in this section, let’s take a moment to discuss an old feature of BGP that Cisco disables by default for you. The feature is called BGP synchronization. For proof that Cisco has disabled this feature on your device, just perform a show running-configuration on one of your lab BGP speakers and under the BGP process you will find the command no synchronization. If enabled, the synchronization feature prevents a BGP speaker from entering prefixes into BGP...
This post is the 3rd in a series of Border Gateway Protocol (BGP) posts. If you missed either of the first two, here are the links:
Now, in this post, you'll learn about how BGP neighborships are formed, within an autonomous system, between autonomous systems, and even between routers that are not directly connected. Also, we'll check out BGP authentication.
Given that BGP is an AS-to-AS routing protocol, it would make good sense that external BGP (i.e. eBGP) is a key ingredient in its operations. The very first thing that we need to keep in mind with eBGP is that the standards are built so that there is a requirement for a direct connection. This is something that we can work around (of course), but this point is worth consideration. Because a direct connection is assumed, the BGP protocol does two things:
Part 1 of our blog series on Border Gateway Protocol (BGP) gave you an overview of BGP and then delved into BGP message types and neighbor states. Now, in this post, you'll learn about one of the most challenging aspects of BGP, how it makes its path selection decision. While routing protocols such as RIP, OSPF, and EIGRP each have their own metrics used to pick the "best" path to a destination network, BGP uses a collection of path attributes (PAs).
When your BGP speaker receives a BGP prefix, there are going to be many path attributes tagged to it, and we know that these are going to be critical when it comes to BGP doing things like choosing a very best path to a destination. Interestingly, not all of these path attributes are created equal.
All BGP path attributes fall into one of four main categories. Note that this list also provides example attributes in each category. Do not be too concerned with these specific attribute values now, as you will...
One of the most intimidating topics for Cisco certification candidates in the Route/Switch track is Border Gateway Protocol (BGP). To help remove the FUD (Fear, Uncertainty, and Doubt) surrounding BGP, I'll be sharing a series of blog posts with you to help demystify this routing protocol. In this first post of the series, you'll be introduced to the very basics of BGP and learn about its various message types and states.
Let’s face it - Border Gateway Protocol is just incredibly unique, especially when we compare it to other routing protocols. The very first thing that makes BGP so unique, is what it does for us. It is our only Exterior Gateway Protocol (EGP) in major use today. We know we have our Interior Gateway Protocols (IGPs), and that would be like OSPF running inside of an autonomous system. But BGP is an EGP, which means that it is (usually) going to take prefixes that are inside an autonomous system and send those to other autonomous systems....
As a redundancy measure, it’s possible to deploy multiple Cisco ASAs together in a failover configuration, also known as a High Availability Implementation. This requires that the ASAs have identical software, licensing, memory, and interfaces. There are three possible high availability options to protect against downtime, which we'll explore here.
Active/Standby Failover Implementation: In this model, only one of the firewalls is responsible for processing traffic, while the other is designated as a hot standby. The standby device has the ability to take over traffic processing duties in the event that the active device fails.
Active/Active Failover Implementation: In this model, both firewalls actively process traffic as a cluster. The network is able to tolerate the failure of one of the devices, since they are performing identical duties.
This implementation is a bit more complex and requires multiple context mode. With multiple context mode, it’s possible to...
This post is the fourth in a series of posts on route redistribution. If you haven't yet read the first three, here are the links:
Up until now in this series, we’ve seen the need for route redistribution, looked at a basic configuration, saw how we could filter specific routes from being redistributed, and learned how to prevent a routing loop by tagging redistributed routes. In this final route redistribution post, we want to check out route redistribution with IPv6, and how that configuration varies a bit from what we’ve done previously with IPv4 networks.
First, consider a router running a routing protocol; let’s say it’s OSPF in this instance. Also, let’s say that router has several interfaces that are participating in the OSPF routing protocol. On that same router, imagine we’re running...
Cisco Zone-Based Policy Firewalls are a more modern implementation of the interface-based stateful inspection. This allows you to group interfaces into zones, which have similar functions or features. This allows for stateful packet inspection and application control, and a much more granular firewall policy.
In this video, I'll discuss common ZPF concepts and walks through a basic CLI implementation.
All the best,