# MPLS Published articles for MPLS. This is one page of public article previews, not the complete archive. Follow Next page to continue. Summaries are not the original full articles. ## MPLS/VPN with SR-MPLS Core DevFeed: [MPLS/VPN with SR-MPLS Core]() Original publisher: [Read original article]() Published: 2026-09-15T05:45:00Z Content type: article Language: en Sources: [ipSpace.net blog]() Topics: [SR-MPLS](), [MPLS VPN](), [networking](), [BGP](), [IS-IS](), [Network](), [GitHub]() Tags: [bgp](), [devices](), [github](), [is-is](), [mpls](), [mpls-vpn](), [netlab](), [sr-mpls](), [vpn]() ### AI overview This article explains how to build and test an MPLS/VPN service over an SR-MPLS core. It describes the required lab topology changes, including enabling MPLS/VPN, disabling LDP, configuring PE routers with IS-IS, SR-MPLS, BGP, MPLS, and VRF modules, and moving PE-to-host links into tenant VRFs. It also outlines how to run the lab using GitHub Codespaces, an Arista cEOS container, and netlab. ### Source excerpt As we discussed in the BGP-Free Core with SR-MPLS blog post, SR-MPLS works as a drop-in replacement for the traditional MPLS control plane. No wonder it works well (when properly implemented) with MPLS/VPN services - the second "fun" scenario in my ITNOG10 Segment Routing workshop. It uses the same topology as the BGP-Free Core scenario: Simplest possible MPLS/VPN network with SR-MPLS core Read more ... ## BGP-Free Core with SR-MPLS DevFeed: [BGP-Free Core with SR-MPLS]() Original publisher: [Read original article]() Published: 2026-09-03T05:30:00Z Content type: article Language: en Sources: [ipSpace.net blog]() Topics: [SR-MPLS](), [BGP](), [networking](), [Network](), [Routing (disambiguation)](), [Containers](), [Linux](), [GitHub]() Tags: [bgp](), [containers](), [edge](), [examples](), [github](), [is-is](), [linux](), [mpls](), [netlab](), [network](), [router](), [routing](), [sr-mpls]() ### AI overview This article demonstrates how to build a BGP-free transport core with SR-MPLS using netlab. It describes a lab topology with IS-IS, BGP, Linux container hosts, and PE routers, then shows how SR-MPLS labels provide end-to-end connectivity without BGP routes on the core router. ### Source excerpt The beauty of SR-MPLS is that it's a drop-in replacement for the traditional (LDP- or RSVP-based) MPLS control plane. For example, you could replace LDP with SR-MPLS in a network using MPLS to implement a BGP-free transport core, and it just keeps working. This scenario was the first "fun" scenario in the ITNOG10 Segment Routing workshop. The core network uses the same topology as in the previous examples; I added two hosts and BGP routing. Simplest possible network using a BGP-free core Read more ... ## Multivendor SR-MPLS DevFeed: [Multivendor SR-MPLS]() Original publisher: [Read original article]() Published: 2026-08-25T05:44:00Z Content type: tutorial Language: en Sources: [ipSpace.net blog]() Topics: [SR-MPLS](), [networking](), [Routing (disambiguation)](), [IS-IS](), [GitHub]() Tags: [github](), [installation](), [is-is](), [mpls](), [netlab](), [network](), [routing](), [sr-mpls]() ### AI overview This tutorial demonstrates a multivendor SR-MPLS network built with netlab using Arista EOS, FRRouting, and SR Linux. It explains vendor-specific Segment Routing Global Block ranges, prefix segments, and MPLS LFIB label swapping, then outlines how to launch the lab through GitHub Codespaces. ### Source excerpt Summer is almost over, and it's time to resume regular programming with the next example from the Segment Routing workshop I had at ITNOG10: multi-vendor SR-MPLS. I used the same lab topology as in the previous examples but deployed Arista EOS on PE1, FRRouting on P, and SR Linux on PE21 Read more ... ## Introducing the J2sw MTU and Encapsulation Calculator DevFeed: [Introducing the J2sw MTU and Encapsulation Calculator]() Original publisher: [Read original article]() Author: j2sw Published: 2026-07-28T16:37:53Z Content type: tutorial Language: en Sources: [Justin Wilson (j2sw)]() Topics: [Network](), [Tool](), [Ethernet](), [VXLAN]() Tags: [calculator](), [cisco](), [ethernet](), [fragmentation](), [gre](), [headers](), [ipsec](), [ipv4](), [ipv6](), [juniper](), [mikrotik](), [mpls](), [mtu](), [network-engineering-resources](), [network-tools](), [network-troubleshooting](), [overhead](), [payload](), [pppoe](), [vlan](), [vxlan]() ### AI overview The article introduces the J2SW MTU and Encapsulation Calculator, which estimates inner IP MTU and required underlay MTU for combinations of PPPoE, GRE, VLAN, MPLS, VXLAN, and other encapsulations. It explains how Layer 2 tags affect Ethernet frame size separately from IP MTU and describes overhead calculations, including cases where fragmentation can be avoided. ### Source excerpt Ever wondered what the effects of different combinations of PPPoE, GRE, and others have on the MTU of a packet? I am excited to announce the first of many J2 Network tools: the J2SW MTU and Encapsulation Calculator. You select the service MTU and the encapsulation used on the path. The calculator then works out ... Read more The post Introducing the J2sw MTU and Encapsulation Calculator appeared first on Justin Wilson (j2sw). ## SR-MPLS with OSPFv2 DevFeed: [SR-MPLS with OSPFv2]() Original publisher: [Read original article]() Published: 2026-06-15T06:12:00Z Content type: tutorial Language: en Sources: [ipSpace.net blog]() Topics: [SR-MPLS](), [networking](), [Routing (disambiguation)](), [Protocol (disambiguation)](), [IS-IS](), [GitHub]() Tags: [container](), [github](), [is-is](), [mpls](), [netlab](), [ospf](), [protocol](), [routing](), [sr-mpls]() ### AI overview A hands-on tutorial showing how to configure and inspect SR-MPLS over OSPFv2 with netlab. It explains the OSPFv2 opaque LSAs used to advertise SR-MPLS information and notes that the resulting MPLS forwarding table matches the comparable IS-IS example. ### Source excerpt I started my part of the Segment Routing workshop @ ITNOG10 exploring SR-MPLS with IS-IS (simple SR-MPLS, dual-stack SR-MPLS, SR-MPLS over unnumbered IPv4 interfaces). Next step: let's change the routing protocol to OSPF while using the same network topology: Read more ... ## SR-MPLS over Unnumbered Interfaces DevFeed: [SR-MPLS over Unnumbered Interfaces]() Original publisher: [Read original article]() Published: 2026-06-01T06:03:00Z Content type: tutorial Language: en Sources: [ipSpace.net blog]() Topics: [SR-MPLS](), [IS-IS](), [networking](), [Protocol (disambiguation)]() Tags: [container](), [demo](), [examples](), [github](), [implementation](), [installation](), [interfaces](), [ipv4](), [is-is](), [mpls](), [netlab](), [network](), [protocol](), [routing](), [sr-mpls](), [traffic-engineering]() ### AI overview This tutorial demonstrates SR-MPLS over unnumbered IPv4 point-to-point interfaces using netlab and IS-IS. It explains the resulting SR-MPLS and IS-IS advertisements, including adjacency and prefix segments, and provides steps for trying the lab through GitHub Codespaces and an Arista cEOS container. ### Source excerpt After the simple SR-MPLS demo and the dual-stack SR-MPLS setup, it was time for the next obvious question: Does SR-MPLS work over unnumbered IPv4 interfaces1, assuming the implementation of the underlying routing protocol supports them? Of course it does; let's go through the details, using the same topology I used throughout the Segment Routing workshop @ ITNOG10. Read more ... ## Dual-Stack SR-MPLS DevFeed: [Dual-Stack SR-MPLS]() Original publisher: [Read original article]() Published: 2026-05-21T06:16:00Z Content type: tutorial Language: en Sources: [ipSpace.net blog]() Topics: [SR-MPLS](), [networking](), [IS-IS](), [Routing (disambiguation)](), [Demo](), [GitHub]() Tags: [github](), [implement](), [ipv4](), [ipv6](), [is-is](), [links](), [mpls](), [netlab](), [network](), [router](), [routing](), [space](), [sr-mpls]() ### AI overview This tutorial demonstrates a dual-stack SR-MPLS lab built with netlab. It explains IPv4 and IPv6 SID addressing, loopback and core-link address pools, and the resulting IS-IS and MPLS forwarding-table entries. ### Source excerpt After the introduction to SR-MPLS demo I did during the Segment Routing workshop @ ITNOG10, we moved to dual-stack SR-MPLS - can we assign node segment identifiers (SIDs) to IPv4 and IPv6 prefixes? The demo used the same three-router network as the previous one, with IPv4 SIDs starting at one and IPv6 SIDs starting at 101: Read more ... ## Reorganized ipSpace.net Segment Routing Resources DevFeed: [Reorganized ipSpace.net Segment Routing Resources]() Original publisher: [Read original article]() Published: 2026-05-11T06:18:00Z Content type: article Language: en Sources: [ipSpace.net blog]() Topics: [Segment Routing over IPv6 (SRv6)](), [Segment Routing with MPLS Labels (SR-MPLS)](), [networking]() Tags: [ipv6](), [mpls](), [resources](), [segment-routing-over-ipv6-srv6](), [segment-routing-with-mpls-labels-sr-mpls](), [sr-mpls](), [srv6]() ### AI overview The author reorganized the Segment Routing blog category into separate resources for Segment Routing with MPLS Labels (SR-MPLS) and Segment Routing over IPv6 (SRv6), ahead of a planned series covering sample SR-MPLS workshop topologies and printouts. ### Source excerpt I created nine sample SR-MPLS topologies for the ITNOG 10 SR-MPLS workshop, and of course, we ran out of time. I plan to cover those topologies and resulting printouts in a series of blog posts; to prepare for those, I cleaned up and reorganized the Segment Routing blog category, which is now split into two: Segment Routing with MPLS Labels (SR-MPLS) Segment Routing over IPv6 (SRv6) Hope you'll find them useful! Also, if you know of other non-vendor Segment Routing resources, please leave a comment, email me, or submit a pull request. ## SR-MPLS Workshop Materials DevFeed: [SR-MPLS Workshop Materials]() Original publisher: [Read original article]() Published: 2026-04-20T05:44:00Z Content type: article Language: en Sources: [ipSpace.net blog]() Topics: [SR-MPLS](), [networking](), [Routing (disambiguation)]() Tags: [2025](), [mpls](), [presentation](), [routing](), [sr-mpls]() ### AI overview A short post shares materials from an SR-MPLS workshop held at ITNOG 10 in Bologna, including a Segment Routing presentation, hands-on workshop slides, lab topologies, and usage guidelines. ### Source excerpt We had a wonderful SR-MPLS workshop @ ITNOG 10 in Bologna on April 20th 2025. If you missed it, explore: The Segment Routing: from Theory to Practice presentation by Tiziano Tofoni The slide deck for the hands-on part of the workshop The lab topologies, and the usage guidelines. ## IPv4 ECMP Works on Arista cEOS Release 4.35.2F DevFeed: [IPv4 ECMP Works on Arista cEOS Release 4.35.2F]() Original publisher: [Read original article]() Published: 2026-03-12T09:09:00Z Content type: opinion Language: en Sources: [ipSpace.net blog]() Topics: [IP routing](), [networking](), [Linux]() Tags: [ip](), [ip-routing](), [ipv4](), [linux-kernel](), [mpls](), [release](), [switching]() ### AI overview The article reports that IPv4 ECMP works on Arista cEOS release 4.35.02F, with traffic spreading across multiple nodes in the author's lab topology. It also observes that forwarded traffic uses ECMP while locally originated traffic does not, despite different routing-table entries. ### Source excerpt When I wrote about the anycast-ECMP-in-MPLS behavior in 2011, I had to use Cisco IOS to prove that ECMP worked, since Arista cEOS (running the Linux kernel for IP forwarding) didn't install more than one equal-cost path into the Linux forwarding table. Arista cEOS got better in the meantime; IPv4 ECMP works like a charm on cEOS release 4.35.02F. With the same lab topology I'd used in 2021, I was able to see the traffic spread across multiple nodes: Read more ... ## netlab 26.03: EVPN/MPLS, IOS XR Features DevFeed: [netlab 26.03: EVPN/MPLS, IOS XR Features]() Original publisher: [Read original article]() Published: 2026-03-10T08:11:00Z Content type: release Language: en Sources: [ipSpace.net blog]() Topics: [releases](), [Release notes](), [evpn](), [BGP](), [MPLS VPN](), [SR-MPLS](), [Cisco](), [networking](), [VXLAN]() Tags: [bgp](), [cisco](), [evpn](), [getting-started](), [github](), [guide](), [improvements](), [installation](), [issue](), [mpls](), [mpls-vpn](), [netlab](), [open](), [release](), [release-notes](), [routing](), [sr-mpls](), [vxlan]() ### AI overview The netlab 26.03 release adds Cisco IOS XR capabilities, Juniper cRPD support, EVPN/VXLAN support on Juniper platforms, OpenBSD BGP support, SR-MPLS support for OSPFv2, and EVPN/MPLS improvements. ### Source excerpt netlab release 26.03 is out. Here are the highlights: New Cisco IOS XR features: SR-MPLS, MPLS/VPN, MPLS 6PE, EVPN over MPLS, VRRP, BGP session parameters, routing policies, prefix filters, AS-path filters, community filters, and static routes Juniper cRPD support (mostly by @leec-666) EVPN/VXLAN on Juniper vPTX and vJunos-router by @rickycraft OpenBSD BGP support by @remilocherer SR-MPLS support for OSPFv2 on EOS, FRR, IOS XE, IOS XR EVPN/MPLS improvements, including using SR-MPLS transport For even more details, check the release notes. Read more ... ## The Tale of Two EVPN/MPLS Encapsulations DevFeed: [The Tale of Two EVPN/MPLS Encapsulations]() Original publisher: [Read original article]() Published: 2026-03-04T07:09:00Z Content type: article Language: en Sources: [ipSpace.net blog]() Topics: [evpn](), [Testing](), [BGP](), [Cisco](), [Ethernet]() Tags: [bgp](), [cisco](), [deep-dive](), [ethernet](), [evpn](), [mpls](), [test](), [testing]() ### AI overview A technical investigation of EVPN/MPLS netlab integration tests compares Arista EOS and Cisco IOS/XE encapsulations. Arista EOS passes the bridging test, while Cisco IOS/XE establishes the control plane but encounters ARP failures that packet captures trace to differing MPLS payload handling and control-word expectations. ### Source excerpt I decided it was high time to create EVPN/MPLS netlab integration tests and wanted to use the same approach I used for the EVPN/VXLAN ones: One of the PE-devices is the device we want to test The other PE-device is a device that is known to work (ideally, an FRRouting container). Bonus points if the other PE-device can generate operational data in JSON format. Using a device for which we already have a validation plugin is close to perfection. Add a P-router in the middle because MPLS. Attach some hosts to the two PE-devices (we're testing two MAC-VRFs in the final version of the test) After validating everything that can reasonably be validated (OSPF session, IBGP session, EVPN AF on IBGP session), do the end-to-end pings and hope for the best. This is the graph netlab created from the lab topology: Read more ... ## netlab: Using L3VPN (MPLS/VPN) with SR-MPLS Core DevFeed: [netlab: Using L3VPN (MPLS/VPN) with SR-MPLS Core]() Original publisher: [Read original article]() Published: 2026-03-02T10:39:01Z Content type: tutorial Language: en Sources: [ipSpace.net blog]() Topics: [MPLS VPN](), [SR-MPLS](), [BGP](), [Containers](), [IS-IS](), [Linux](), [GitHub]() Tags: [bgp](), [containers](), [github](), [is-is](), [linux](), [mpls](), [mpls-vpn](), [netlab](), [sr-mpls]() ### AI overview This tutorial shows how to use netlab to build an MPLS/VPN lab with an SR-MPLS core. It describes a topology using Arista EOS cEOS containers, Linux containers, FRRouting containers, IS-IS, BGP, MPLS, SR-MPLS, and VRFs, and explains how to start the lab in a Linux VM, Windows Subsystem for Linux, a Mac with Apple Silicon, or GitHub Codespaces. ### Source excerpt Someone recently asked me whether it's possible to use netlab to build an MPLS/VPN (technically, BGP/MPLS IP VPN) lab with SR-MPLS core. Of course, let's build a simple lab using Arista EOS and Linux containers to implement this topology: Lab topology Here's the lab topology we'll use (also available on GitHub): Read more ... ## Configuring 6PE Route Reflector on Cisco IOS DevFeed: [Configuring 6PE Route Reflector on Cisco IOS]() Original publisher: [Read original article]() Published: 2026-02-26T07:19:00Z Content type: tutorial Language: en Sources: [ipSpace.net blog]() Topics: [Cisco](), [BGP](), [configuration](), [networking](), [Ansible](), [NETCONF](), [REST API]() Tags: [ansible](), [bgp](), [cisco](), [configuration](), [logging](), [mpls](), [netconf](), [netlab](), [rest-api]() ### AI overview The article explains a Cisco IOS configuration issue affecting BGP route reflectors for MPLS 6PE and L3VPN. IPv6 labeled-unicast and VPNv6 address-family commands may appear to apply through Ansible's ios_config module but not persist in the BGP configuration unless IPv6 routing is enabled with ipv6 unicast-routing. The article also argues that NETCONF or REST API mechanisms could report configuration failures more consistently than CLI-based automation. ### Source excerpt Imagine you want to deploy a BGP route reflector for MPLS 6PE or L3VPN service. Both services run over MPLS LSPs, use IPv4 BGP sessions, and use IPv4 next hops for BGP routes. There's absolutely no reason to need IPv6 routing on a node that handles solely the control-plane activity (it never appears as a BGP next hop anywhere), right? Cisco IOS disagrees, as I discovered when running route reflector integration tests for netlab 6PE and (MPLS) L3VPN functionality. Most platforms failed those tests because we forgot to configure route-reflector-clients in labeled IPv6 and VPNv4/VPNv6 address families1. That was easy to fix, but the IOS-based devices were still failing the tests, with nothing in the toolchain ever complaining about configuration problems. Read more ... ## Who can light fibre in India? DevFeed: [Who can light fibre in India?]() Original publisher: [Read original article]() Published: 2026-02-21T20:49:05Z Content type: article Language: en Sources: [Personal blog of Anurag Bhatia]() Topics: [Internet](), [Cloud](), [hosting](), [datacenter]() Tags: [backhaul](), [cloud](), [connectivity](), [datacenter](), [hosting](), [india](), [infrastructure](), [mpls](), [regulatory](), [routers](), [vlan]() ### AI overview The article discusses Indian telecom licensing rules for deploying, lighting, and reselling fibre outside a building. It explains that IP-1 providers may lease passive dark-fibre infrastructure but may not light it, while appropriately licensed ISPs may light fibre for end-user internet access and their own backhaul, not point-to-point connectivity. ### Source excerpt Friend and his two homes... Recently, a friend of mine mentioned his plan to procure dark fibre to connect two of his homes. His idea was straightforward - get LCO to give a dark strand between both homes and run Bidi optics over it. I ended up telling him that while his idea is technically fine, as modern optics can easily cover that sort of distance, it would be illegal as per Indian telecom laws! It wasn't just him, but numerous content players, hosting companies, and Cloud players find it a bit odd when they find this out. In this post, I will document what is allowed and what is not allowed. Advance warning: I am a technical person & do not know much about regulatory. Whatever I am sharing here is what I have learned from my friends who have expertise in the subject. Indian telecom rules are overly complex and can have a different set of interpretations, and often go into the grey area. I welcome readers to share feedback if they are aware of something which isn't correct as per the regulation. With that warning out of the way, I will proceed with the post. Understanding licensing In India, when fibre is going outside of a given building, one needs to have a license to light it. In fact, not just "lighting up a dark fibre" but to deploy and resell dark fibre, one needs a license (IP-1). Infrastructure Provider Category 1 (or IP-1) is considered an easy license which can be used to sell passive assets such as dark fibre, ducts, towers, etc. Active infra i.e lighting up fibre, is not allowed under this license, and it's expected that an IP-1 holder leases their dark fibre only to a license holder who is authorised to light the fibre. Within a building, campus, datacenter, home etc one can deploy a light fibre but as soon as it goes outside of that it becomes a bit of a grey area depending on the use case. An Internet Service Provider (ISP) holding an ISP license or Unified License with ISP authorisation can light fibre but only for two specific purposes: Offering i ## On MPLS Forwarding Performance Myths DevFeed: [On MPLS Forwarding Performance Myths]() Original publisher: [Read original article]() Published: 2026-02-05T07:20:00Z Content type: opinion Language: en Sources: [ipSpace.net blog]() Topics: [networking](), [Ethernet](), [Cisco](), [Hardware]() Tags: [cisco](), [devices](), [hardware](), [ietf](), [ip](), [mpls](), [performance](), [switching]() ### AI overview The article examines claims about the original motivation for MPLS, arguing that aggregate forwarding performance in core devices mattered more than accelerating individual IP table lookups. It describes how mid-1990s service providers combined routers at the network edge with ATM switches in the core because routers lacked sufficient aggregate bandwidth. ### Source excerpt Whenever I claim that the initial use case for MPLS was improved forwarding performance (using the RFC that matches the IETF MPLS BoF slides as supporting evidence), someone inevitably comes up with a source claiming something along these lines: The idea of speeding up the lookup operation on an IP datagram turned out to have little practical impact. That might be true1, although I do remember how hard it was for Cisco to build the first IP forwarding hardware in the AGS+ CBUS controller. Switching labels would be much faster (or at least cheaper), but the time it takes to do a forwarding table lookup was never the main consideration. It was all about the aggregate forwarding performance of core devices. Anyhow, Duty Calls. It's time for another archeology dig. Unfortunately, most of the primary sources irrecoverably went to /dev/null, and personal memories are never reliable; comments are most welcome. Read more ... ## On MPLS Paths, Tunnels and Interfaces DevFeed: [On MPLS Paths, Tunnels and Interfaces]() Original publisher: [Read original article]() Published: 2026-01-20T06:29:00Z Content type: opinion Language: en Sources: [ipSpace.net blog]() Topics: [Network](), [MPLS-TE](), [Routing (disambiguation)](), [IP routing](), [Protocol (disambiguation)](), [VXLAN]() Tags: [gre](), [ip-routing](), [mpls](), [network](), [networking-fundamentals](), [protocol](), [routing](), [vxlan]() ### AI overview The article explains the fundamental difference between overlay tunnels such as GRE, IPsec, and VXLAN and MPLS paths. Tunnels connect separate overlay segments across an underlay, while MPLS paths improve forwarding within the same network; routing protocols are used differently in these designs. ### Source excerpt One of my readers attempted to implement a multi-vendor multicast VPN over MPLS but failed. As a good network engineer, he tried various duct tapes but found that the only working one was a GRE tunnel within a VRF, resulting in considerable frustration. In his own words: How is a GRE tunnel different compared to an MPLS LSP? I feel like conceptually, they kind of do the same thing. They just tunnel traffic by wrapping it with another header (one being IP/GRE, the other being MPLS). Instead of going down the "how many angels are dancing on this pin" rabbit hole (also known as "Is MPLS tunneling?"), let's focus on the fundamental differences between GRE/IPsec/VXLAN tunnels and MPLS paths. Read more ... ## One-Arm Hub-and-Spoke VPN on Arista EOS DevFeed: [One-Arm Hub-and-Spoke VPN on Arista EOS]() Original publisher: [Read original article]() Published: 2025-11-11T06:28:00Z Content type: article Language: en Sources: [ipSpace.net blog]() Topics: [MPLS VPN](), [networking](), [IP routing](), [configuration]() Tags: [blog-post](), [design](), [mpls](), [mpls-vpn](), [netlab](), [release](), [router](), [routing]() ### AI overview This article demonstrates how Arista EOS release 4.34.2F enables a different MPLS label for the default route, allowing one-arm hub-and-spoke VPN traffic to pass through the hub CE router as expected. It also describes updated lab templates and configuration for Arista EOS and FRR. ### Source excerpt In September 2024, I described how you can build One-Arm Hub-and-Spoke VPN with MPLS/VPN. In that blog post, I mentioned that the solution doesn't work on Arista EOS because it allocates MPLS labels to whole VRFs (per-VRF label allocation) (the original post has been updated). In early September, I received an email from Daniel Blažek telling me that Arista fixed this particular annoyance in the EOS release 4.34.2F. It still uses per-VRF label allocation, but now, you can assign a different label to the default route. Let's see how that works with our one-arm hub-and-spoke topology: Read more ... ## A netlab tutorial for building network labs, including an MPLS network with custom multi-vendor device configuration DevFeed: [A netlab tutorial for building network labs, including an MPLS network with custom multi-vendor device configuration]() Original publisher: [Read original article]() Published: 2025-09-01T06:22:00Z Content type: tutorial Language: en Sources: [ipSpace.net blog]() Topics: [Network](), [Tutorial](), [configuration]() Tags: [build](), [configuration](), [mpls](), [netlab](), [network](), [tutorial](), [worth-reading]() ### AI overview Suresh Vina published a netlab tutorial that progresses from basic concepts to building an MPLS network with custom multi-vendor device configuration. ### Source excerpt Suresh Vina published a great netlab tutorial, going from the very basics to a full-blown MPLS network with custom multi-vendor device configuration. Thank you! ## How Internet Exchanges (IX) Help Enterprises Save Bandwidth & Costs DevFeed: [How Internet Exchanges (IX) Help Enterprises Save Bandwidth & Costs]() Original publisher: [Read original article]() Author: Shivam Anand Published: 2025-08-30T13:09:53Z Content type: article Language: en Sources: [Shivam Anand - DevOps & Cloud Engineering Blog]() Topics: [Internet](), [networking](), [BGP](), [Routing (disambiguation)](), [Latency](), [Scalability](), [Cloud]() Tags: [bandwidth-savings](), [bgp](), [cloud-connectivity](), [cost-savings](), [data-center-interconnect](), [enterprise-networking](), [firewall](), [internet](), [internet-exchange](), [isp-costs](), [ix](), [ixp](), [latency](), [mpls](), [paloalto-firewall](), [peering](), [remote-peering](), [scalability](), [university-connectivity](), [vlan]() ### AI overview This article explains how enterprises can use Internet Exchanges (IX) and VLAN-based multi-campus links to exchange traffic directly with networks, cloud providers, and content platforms. It describes potential bandwidth and transit-cost savings, lower latency, improved performance, and more flexible scaling, with university and network-architecture examples. ### Source excerpt Discover how connecting your enterprise infrastructure to Internet Exchanges (IX) can reduce bandwidth costs, improve performance, and scale efficiently. Includes cost-saving examples, diagrams, and real-world scenarios. ## Multi-Layer Switching and Tunneling DevFeed: [Multi-Layer Switching and Tunneling]() Original publisher: [Read original article]() Published: 2025-05-30T06:20:00Z Content type: article Language: en Sources: [ipSpace.net blog]() Topics: [networking](), [Routing (disambiguation)](), [MPLS-TE](), [BGP](), [Ethernet](), [Protocol (disambiguation)]() Tags: [bgp](), [ethernet](), [mpls](), [mpls-te](), [networking](), [networking-fundamentals](), [protocol](), [router](), [routing](), [switching]() ### AI overview The article explains multi-layer switching, where edge devices forward traffic at a higher networking layer while core devices forward it at a lower layer. It describes IP forwarding over bridged Ethernet and virtual-circuit-like approaches using MPLS, MPLS-TE, BGP, and segment routing. ### Source excerpt When deep-diving into the confusing terminology of switching, routing, and bridging, I mentioned you could perform packet forwarding at different layers of a networking stack. In this blog post, we'll explore what happens when we combine packet forwarding on multiple layers within a single network, resulting in multi-layer switching, where edge devices perform Layer n forwarding (usually Layer 3), and core devices perform Layer n-1 forwarding (typically Layer 2). Each layer can use any forwarding paradigm you choose. However, since we generally use IP at Layer 3, edge devices typically perform hop-by-hop destination-based forwarding, while core devices can use alternative methods. Read more ... ## Traffic steering into label-switched paths (LSPs) DevFeed: [Traffic steering into label-switched paths (LSPs)]() Original publisher: [Read original article]() Published: 2025-03-10T07:12:00Z Content type: article Language: en Sources: [ipSpace.net blog]() Topics: [SR-MPLS](), [MPLS-TE](), [Software-defined networking](), [Network](), [NETCONF]() Tags: [mpls](), [mpls-te](), [netconf](), [network](), [sdn](), [traffic-engineering](), [worth-reading]() ### AI overview The article discusses steering network traffic into label-switched paths (LSPs) built with SR-MPLS, MPLS-TE, or an SDN controller. It explains that installing LSPs is only part of the task; network devices must also be configured to use them. ### Source excerpt You can use SR-MPLS, MPLS-TE, or an SDN controller to build virtual circuits (label-switched paths) across the network core. The controller can push the LSPs into network devices with PCEP, BGP-LU, or some sort of NETCONF/RESTCONF trickery. Unfortunately, you're only half done once you have installed the LSPs. You still have to persuade the network devices to use them. Welcome to the confusing world of traffic steering explored in the Loopback as a Service blog post by Dmytro Shypovalov. Read more ... ## Using an SDN Controller for RSVP-TE DevFeed: [Using an SDN Controller for RSVP-TE]() Original publisher: [Read original article]() Published: 2025-02-20T07:14:00Z Content type: opinion Language: en Sources: [ipSpace.net blog]() Topics: [Software-defined networking](), [SR-MPLS]() Tags: [article](), [mpls](), [mpls-te](), [sdn](), [sr-mpls](), [worth-reading]() ### AI overview A recommendation for an article about using an SDN controller with RSVP-TE. It discusses why RSVP-TE may still be preferred over SR-MPLS, the role of an SDN controller, and RSVP/SR coexistence and interworking. ### Source excerpt Dmytro Shypovalov published another article well worth reading: why should you use an SDN controller for RSVP-TE. It covers: The reasons people might still prefer RSVP-TE over SR-MPLS and the current state of RSVP-TE What an SDN controller might bring to the RSVP-TE world SR/RSVP coexistence and interworking Have fun! ## Understanding and Observing the BGP Connect State DevFeed: [Understanding and Observing the BGP Connect State]() Original publisher: [Read original article]() Published: 2025-01-30T06:55:00Z Content type: article Language: en Sources: [ipSpace.net blog]() Topics: [BGP](), [Finite-state machine](), [Cisco]() Tags: [arp](), [bgp](), [cisco](), [how-to](), [machine](), [mpls](), [state](), [tcp]() ### AI overview The article explains why the BGP Connect state is difficult to observe, especially on Cisco IOS, whose implementation predates the state and does not display it. It describes the BGP state transitions and conditions that can cause a peer to remain in Connect long enough to observe, including dropped TCP SYN packets and certain routing or filtering configurations. ### Source excerpt I got this question from Paul: Have you ever seen a BGP peer in the "Connect" state? In 20 years, I have never been able to see or reproduce this state, nor any mention in a debug/log. I am starting to believe that all the documentation is BS, and this does not exist. The BGP Finite State Machine (FSM) (at least the one defined in RFC 4271 and amended in RFC 9687) is "a bit" hard to grasp but the basics haven't changed from the ancient days of RFC 1771: Read more ... [Next page]()