No Accident BGP is used for VPNs

Border Gateway Protocol (BGP) is used in many roles. So many, that some worry about the impact on Internet stability. The distribution of flowspec rules by BGP that was implicated in the recent Centurylink outage was a reminder to some of that potential, notwithstanding a hopefully fully understanding of the outage in the future. Most…

Segment routing: Less state, less capability. IP/MPLS RSVP-TE: More state, more capability

The Important Segment routing (for MPLS) supports explicit routes with LESS STATE than IP/MPLS RSVP-TE, but WITHOUT* bandwidth reservation signaling IP/MPLS with RSVP-TE supports explicit routes, with MORE STATE than Segment Routing (for MPLS), but WITH bandwidth reservation signaling Segment routing: Less state, less capability. IP/MPLS RSVP-TE: More state, more capability. *Not withstanding “https://tools.ietf.org/html/draft-ietf-spring-resource-aware-segments-00” and management interfaces, which will be discussed below….

Book Review: Navigating Network Complexity

From a small number of hosts that are unreachable to large Internet outages, complexity sneaks up and bites network operators, sometimes at the most unexpected and undesirable times. While many mistakes in networks are manual configuration errors, the events of August 30th 2020, served to remind, that automated processes can sometimes propagate a mistake, fast,…

You cannot eliminate complexity for the SAME capability & certainty

The common saying in networking “you cannot eliminate complexity, you can only move it around” are words to live by. Providing insight into the combinatorial complexity in engineering tradeoffs. I find it useful to think about the issue in a slightly modified way “You cannot eliminate complexity for the SAME capability (& certainty)”. Information theory points…

We Automate to Grow: The Past and Future of IP Networks

Imagine a world where IP networks did not have dynamic routing protocols. What would be the alternative? Configuring routes via a management system? Would the network with the best management system have a competitive advantage over other networks? How would that network respond to frequent topology changes? Would there be few networks that operated well,…

As Simple as a Static

Dynamic routing changed the networking landscape in ways that can barely be remembered or articulated. Can anyone really imagine a network such as the Internet, with so many different networks (dare I say “internets”), each with their own administrative entity, and administrative policy, with such a rich “mesh” of connectivity/reachability, emerging as it has, with…

Overall Context For Change in Networking

The¬†Network 2025¬†Article made the following assertion which this article expands on: All of IT has been disrupted by hyperscalers and SaaS. Combined, they have both radically changed customer experience(compared to on-prem software models) and operations excellence(compared to traditional IT models). They have also changed business models. It is in the area of operations excellence that the future…

BGP for Service Layer Migration and Perhaps More

The Important Over the next five years (Network 2025), migration will be top of mind for IP Architects and Engineers, as many networks transition to Segment Routing (SR) for MPLS (SR MPLS), Segment Routing for IPv6 (SRv6), IPv6 (without segment routing), and other migration scenarios in between. BGP-based VPNs support numerous forwarding/data planes, enabling the…

Network 2025 and Beyond

Introduction As I continue to iterate on, and flesh out, the Internet Innovation Stack which I will use as a way of organizing my technologies of interest, networking is a natural area for me to dive in, as it is the area of technology I know the best. A typical way of articulating the future of networking,…