Routing
BGP Communities
BGP Communities has to be one of my favorite features added to the BGP protocol.
IP Multicast Routing Concepts
Can you imagine a video conference taking place on a primarily T1 based WAN? Multiple copies of the same video stream being unicast from the host to each participant.
BGP Essentials – The Art of Path Manipulation
Most enterprise networks use BGP to peer with their Internet Service Providers if they want to be multi-homed.
OSPF Graceful Shutdown
Striving to reach that last 9? Looking for a way to increase your uptime while still being able to do maintenance on your network?
HSRP, VRRPd, and GLBP Compared
In the world of first hop redundancy, we have plenty of choices. In order to make the right decision for your network you should know the basics regarding all three.
BGP Tips! multipath load balancing
Previous thoughts on load balancing BGP were that it is not a load balancing protocol and in order to achieve any sort of balanced traffic you would have to perform some sort of …
Bidirectional Forwarding Detection
Bidirectional Forwarding Detection (BFD) is a UDP-based protocol that provides fast (very fast!) routing protocol independent detection of layer-3 next hop failures.
More BGP tricks
At times, the ‘rules of BGP’ don’t fit the needs of our productions networks. When we get into today’s production networks how often do book configurations apply?
Policy Based Routing
Policy based routing is the process of altering a packets path based on criteria other than the destination address, commonly referred to as ‘policy routing’.
Using /31 subnets for point-to-point interfaces
Recently a “colleague”, I use that term very loosely here, was reviewing my recommendations for changes on his network.
Cisco MPLS VRF Configuration and Demo
A while back I asked everyone to vote on what topic they wanted to see next, and by no surprise almost every voted for MPLS VRFs.
Route Selection
One of the most common questions I get concerns path selection within the router.
BGP Security Tips (updated)
For some, BGP is a rather large obtrusive beast of a protocol that scares them half to death.
Layer 2 Ethernet transport over OpenVPN
One of the things I used to deploy frequently at my previous position was transport for other ISPs and businesses.
Using OSPF to create unlicensed full duplex connections.
Recently one of my clients asked me to help resolve an issue at an aggregation point on their network.
How does latency effect throughput?
One of the questions I get asked several times a week by my clients is as such.