# IPv4 Published articles for IPv4. This is one page of public article previews, not the complete archive. Follow Next page to continue. Summaries are not the original full articles. ## One or two nameservers? DevFeed: [One or two nameservers?]() Original publisher: [Read original article]() Author: Geoff Huston Published: 2026-09-15T06:01:49Z Content type: article Language: en Sources: [APNIC Blog]() Topics: [Internet](), [Query (disambiguation)](), [Server](), [Caching]() Tags: [2026](), [africa](), [article](), [china](), [dns](), [europe](), [experiment](), [india](), [internet](), [ipv4](), [ipv6](), [measurement](), [measurements](), [recursive-resolver](), [repeat](), [responses](), [server](), [tech-matters]() ### AI overview This article reports an experiment testing whether serving a DNS zone with two authoritative dual-stack nameservers changes repeated queries. Compared with one nameserver, two nameservers increased the single-query completion rate from 58% to 71% and reduced the average queries per test from 3.43 to 2.57. ### Source excerpt Do multiple dual-stack nameservers increase or decrease repeat DNS queries? The results of this experiment were a complete surprise. ## Cilium 1.20: Gateway API ExternalAuth, TCPRoute/UDPRoute, ENI IPAM for IPv6, and more DevFeed: [Cilium 1.20: Gateway API ExternalAuth, TCPRoute/UDPRoute, ENI IPAM for IPv6, and more]() Original publisher: [Read original article]() Author: Nico Vibert and Donia Chaiehloudj, Cilium Published: 2026-09-14T10:45:49Z Content type: article Language: en Sources: [Cloud Native Computing Foundation]() Topics: [Cilium](), [Open Source](), [API](), [networking](), [Kubernetes](), [Amazon Web Services](), [eBPF](), [VPC](), [nginx]() Tags: [2026](), [api](), [authentication](), [authorization](), [aws](), [blog](), [cilium](), [cloud](), [cni](), [ebpf](), [google](), [ingress-nginx](), [ipv4](), [ipv6](), [kubernetes](), [microsoft](), [network](), [networking](), [nginx](), [open-source](), [release]() ### AI overview Cilium 1.20 expands Gateway API support with ExternalAuth, CORS filters, ListenerSets, TCPRoute, and UDPRoute. The release also introduces extensible datapath plugins, advances networking standardization with Kubernetes, and adds beta IPv6 support for AWS ENI IPAM. ### Source excerpt Cilium 1.20, the second major open source Cilium release of 2026 after Cilium 1.19, is finally here. Three themes stand out in this release: Thank you to every contributor, reviewer and maintainer who made Cilium 1.20... ## Airtel plans to begin RPKI Route Origin Validation rollout on 22 September 2026 DevFeed: [Airtel plans to begin RPKI Route Origin Validation rollout on 22 September 2026]() Original publisher: [Read original article]() Published: 2026-09-14T09:00:47Z Content type: opinion Language: en Sources: [Personal blog of Anurag Bhatia]() Topics: [networking](), [Routing Security](), [Security]() Tags: [airtel](), [apnic-62](), [as9498](), [india](), [ipv4](), [ipv6](), [routing-security](), [rov](), [rpki]() ### AI overview Airtel has told customers it plans to begin rolling out RPKI Route Origin Validation on 22 September 2026. The article examines 726 RPKI-invalid routes in Airtel's table, including 108 IPv4 and 618 IPv6 routes, and discusses their visibility outside India. ### Source excerpt Just back from Mumbai after APNIC 62 and Equinix's India Peering Forum. On excellent news: Airtel has started sending emails to its customers about RPKI RoV (Route Origin Validation). As per the mail, Airtel will start RPKI RoV soon and has mentioned 22 Sep 2026 as the timeline when they will start rolling out RoV. This is excellent news on the routing security front, and kudos to Airtel (AS9498) for taking the lead here among other large Indian backbones. This brings up the important question of how many routes exist in their table which are RPKI RoV invalids as of today? Looking at their announcements, I see the following: RPKI Valids: 33,735 RPKI Unknown: 4632 RPKI invalids: 726 This is for their table, including downstream routes. One can view the complete list of those 726 invalids, including prefix and AS_PATH here. One interesting thing here is that out of 726, 140 are from Airtel fixedline AS24560 and 122 are from Airtel Mobility. In terms of address family, there are 108 invalids from IPv4 and 618 from IPv6. How many of these invalids are single-homed vs multi-homed? This is important to check, as often the argument against RoV given by various operators in past was that they were losing traffic to their competitors. When I checked, I do not see any of these prefixes visible outside of India behind a transit-free / tier 1 network without AS9498 in the path. It could be because Tata Comm AS6453 drops RPKI invalid already & most of these are not dual-homed via Jio AS64049. So unless a less specific RPKI valid announcement is there, these are anyway largely blackholed for now by networks & IXPs doing RoV outside of India. Let's hope other Indian backbones also start doing RPKI RoV soon. Happy routing! 😀 ## Configuring Management IP Addresses to Virtual Network Devices DevFeed: [Configuring Management IP Addresses to Virtual Network Devices]() Original publisher: [Read original article]() Published: 2026-09-14T05:29:00Z Content type: article Language: en Sources: [ipSpace.net blog]() Topics: [networking](), [configuration](), [Orchestration](), [Vagrant](), [Cloud](), [ssh]() Tags: [cli](), [cloud](), [devices](), [dhcp](), [ip](), [ipv4](), [ipv6](), [management](), [netlab](), [network](), [networking](), [orchestration](), [server](), [ssh]() ### AI overview The article explains how to assign predictable management IP addresses to virtual network devices. It contrasts manual console-based setup with automated assignment through orchestration, containers, DHCPv4/DHCPv6, custom Vagrant boxes, and IPv6 mechanisms such as SLAAC. ### Source excerpt It goes without saying that if you want to configure (virtual) network devices with any semi-sane configuration mechanism1, the device must have a working IP address. Here's the time-honored method2 to assign an IP address to a virtual network device: Start the virtual machine (using a GUI)3 Open a new window: either a telnet session to the virtual console port or a full-blown virtual console (GUI) session. Manually configure the IP address, the SSH server, and the user credentials on the first interface. Read more ... ## Welcome to APNIC 62 DevFeed: [Welcome to APNIC 62]() Original publisher: [Read original article]() Author: Timothy Hildred Published: 2026-09-08T03:33:07Z Content type: article Language: en Sources: [APNIC Blog]() Topics: [Internet](), [Networks](), [Cybersecurity](), [DNSSEC](), [threat detection](), [Threat Research](), [FIRST]() Tags: [apnic-62](), [community](), [conference](), [conferences](), [cybersecurity](), [dnssec](), [event](), [events](), [india](), [ipv4](), [ipv6](), [nixi](), [nro](), [policy-sig](), [tech-matters](), [threat-detection]() ### AI overview APNIC 62 in Mumbai previews technical, security, IPv6 deployment, DNSSEC, threat-detection, community, and policy sessions, alongside keynote talks, social events, newcomer activities, and NRO NC voting information. ### Source excerpt APNIC welcomes you to Mumbai, India for APNIC 62. Here is what you can look forward to over the coming days. ## Rootless Podman: Preserving Source IPs DevFeed: [Rootless Podman: Preserving Source IPs]() Original publisher: [Read original article]() Author: Jan Rodak Published: 2026-09-04T14:25:02Z Content type: article Language: en Sources: [blog.podman.io]() Topics: [podman](), [Containers](), [Networks](), [Access Control](), [Logging]() Tags: [blog](), [bridge](), [container](), [containers](), [ipv4](), [ipv6](), [logging](), [networks](), [podman](), [port](), [rate-limiting](), [routing](), [tips-and-tricks]() ### AI overview This article explains how Pesto, a companion tool from the passt project, addresses Rootless Podman's inability to preserve incoming client source IPs on bridge networks. Pesto updates pasta's forwarding table so traffic reaches containers without source-address rewriting, while retaining existing port-mapping capabilities. The article also documents configuration steps, traffic flow, supported networking features, and limitations when switching from the current forwarder. ### Source excerpt Rootless Podman has a long-standing limitation reported since 2020: containers on bridge networks can't see the real source IP of incoming connections. The `rootlessport` userspace proxy rewrites the source to the container's own subnet address, breaking IP-based access control, logging, and rate limiting. Pesto, a new companion tool from the passt project solves this. Pesto [...] ## South Asia SRF highlights Member priorities on IPv6, routing security, and training DevFeed: [South Asia SRF highlights Member priorities on IPv6, routing security, and training]() Original publisher: [Read original article]() Author: Dale Roberts Published: 2026-08-25T06:04:35Z Content type: news Language: en Sources: [APNIC Blog]() Topics: [networking](), [Routing Security](), [SANOG](), [Availability]() Tags: [aspa](), [community](), [deployment](), [development](), [event](), [infrastructure](), [internet](), [ipv4](), [ipv6](), [network](), [networks](), [routing-security](), [rpki](), [sanog](), [south-asia](), [subregional-forum](), [training]() ### AI overview The South Asia APNIC Sub-Regional Forum, held alongside SANOG 44 in Kathmandu, brought together more than 100 Members and regional Internet stakeholders. Discussions emphasized IPv6 deployment, routing security using RPKI, ROV, and ASPA, Internet resource and registry management, policy participation, automation, IPv4 availability, and practical technical training. ### Source excerpt More than 100 APNIC Members attended the South Asia APNIC Sub-Regional Forum alongside SANOG 44 in Kathmandu. Member feedback gathered during the event will help inform APNIC's future priorities across the region. ## APNIC 62 OPM: Just the facts DevFeed: [APNIC 62 OPM: Just the facts]() Original publisher: [Read original article]() Author: Dave Phelan Published: 2026-08-21T02:47:03Z Content type: article Language: en Sources: [APNIC Blog]() Topics: [Internet](), [Networks](), [Protocol (disambiguation)]() Tags: [apnic-62](), [article](), [community](), [dns](), [internet](), [ipv4](), [ipv6](), [management](), [networks](), [open](), [policy](), [policy-development-process](), [policy-sig]() ### AI overview An overview of policy proposals for the APNIC 62 Open Policy Meeting, covering IPv6 allocation flexibility, transitional IPv4 access for IPv6-only networks, and Internet abuse handling. ### Source excerpt The APNIC 62 Open Policy Meeting will consider a diverse set of policy proposals covering IPv4 management, IPv6 allocation practices, and Internet abuse handling. ## Parsing common IPv4 addresses in C# with AVX-512 DevFeed: [Parsing common IPv4 addresses in C# with AVX-512]() Original publisher: [Read original article]() Author: Daniel Lemire Published: 2026-08-19T19:07:48Z Content type: article Language: en Sources: [Daniel Lemire]() Topics: [C#](), [Parsing](), [performance-optimization](), [.NET]() Tags: [avx](), [c-sharp](), [ip](), [ipv4](), [parsing](), [performance]() ### AI overview The article examines parsing common IPv4 address strings in C# for performance. It discusses using SIMD and AVX-512 support in .NET 10, including masked loads for safely loading strings shorter than a SIMD register width. ### Source excerpt We are all familiar with IP addresses such as 192.168.0.1. They are typically written as four numbers in the range 0 to 255 inclusive, separated by dots. In C#, you can parse them with the standard library using IPAddress.TryParse. Pedantic people are quick to point out that IP addresses can take different forms: they can ... Continue reading Parsing IP addresses in C# at crazy speeds ## Deploying IPv6-first EKS on AWS: What Still Doesn't Work, and What It Saves DevFeed: [Deploying IPv6-first EKS on AWS: What Still Doesn't Work, and What It Saves]() Original publisher: [Read original article]() Author: Spiro Stathakis Published: 2026-08-14T08:57:28Z Content type: article Language: en Sources: [RIPE Labs]() Topics: [Amazon Elastic Kubernetes Service](), [Amazon Web Services](), [VPC](), [networking](), [cloud-infrastructure](), [Kubernetes]() Tags: [2026](), [amazon](), [amazon-elastic-kubernetes-service](), [aws](), [cni](), [competition](), [cost](), [ip](), [ipv4](), [ipv6](), [kubernetes](), [nat](), [networking](), [networks](), [vpc]() ### AI overview A field report on deploying an IPv6-first Amazon Elastic Kubernetes Service platform on AWS. It explains how IPv6 pods, VPC networking, and an egress-only Internet gateway reduce dependence on NAT gateways and public IPv4 addresses, while legacy IPv4-only dependencies such as databases, payment APIs, and container registries still impose compatibility requirements and costs. ### Source excerpt In this field report on IPv6-first Amazon Elastic Kubernetes Service (EKS), the isp6 team shares which dependencies still drag IPv4 back in, what they learnt from /28s, and why the saving is large but not automatic. ## Multiple LIR Accounts: Looking Back and Thinking Ahead DevFeed: [Multiple LIR Accounts: Looking Back and Thinking Ahead]() Original publisher: [Read original article]() Author: Marco Schmidt Published: 2026-08-12T12:47:22Z Content type: article Language: en Sources: [RIPE Labs]() Topics: [Internet](), [Networks](), [.NET 11]() Tags: [administration](), [article](), [complexity](), [ip](), [ipv4](), [networks](), [operational](), [policy]() ### AI overview The article examines how allowing RIPE NCC members to operate multiple Local Internet Registry (LIR) accounts evolved from a solution for limited organizational situations into a source of disproportionate operational complexity. It reviews the effects of IPv4 exhaustion, the last /8 policy, and the IPv4 transfer market, then explains the Internet Registry System and the rationale for simplifying the current model. ### Source excerpt Why a feature introduced for a handful of members became one of the RIPE NCC's most complex operational challenges. ## netlab 26.08: ArcOS, VPP (FD.io), ACLs, and DNS DevFeed: [netlab 26.08: ArcOS, VPP (FD.io), ACLs, and DNS]() Original publisher: [Read original article]() Published: 2026-08-10T09:58:00Z Content type: release Language: en Sources: [ipSpace.net blog]() Topics: [Release notes](), [networking](), [Containers](), [configuration](), [Routing (disambiguation)](), [Authorization]() Tags: [access-control](), [configuration](), [dns](), [getting-started](), [github](), [gre](), [installation](), [ipv4](), [ipv6](), [netlab](), [podman](), [release](), [release-notes](), [routing]() ### AI overview netlab 26.08 adds ArcOS support, VPP with FRR or BIRD control planes, SONiC containers, IPv4/IPv6 access control lists, DNS client and server configuration, GRE and WireGuard tunnel support, and Podman support for the clab provider. The article also notes bug fixes, configuration-template changes, upgrade guidance, and documentation for new users. ### Source excerpt netlab release 26.08 brings a few humongous additions: ArcOS support by @roc-ops VPP (FD.io) with FRR or BIRD control plane by @jbemmel SONiC containers (also by @roc-ops) IPv4/IPv6 access control lists in the routing module by @DanPartelly But wait, there's more: Read more ... ## IP Addressing, Part III: Inside the IP Packet DevFeed: [IP Addressing, Part III: Inside the IP Packet]() Original publisher: [Read original article]() Author: Franco Fernando Published: 2026-08-07T09:49:52Z Content type: tutorial Language: en Sources: [The Polymathic Engineer]() Topics: [Network](), [Protocol (disambiguation)]() Tags: [fragmentation](), [internet](), [ipv4](), [ipv6](), [network](), [payload](), [protocol]() ### AI overview This tutorial examines the IPv4 datagram and header fields, explains fragmentation and MTU constraints, discusses why TCP and IP use checksums, and describes changes introduced by IPv6. ### Source excerpt What actually travels on the wire: the IPv4 header, fragmentation, and what IPv6 changed. ## IP Addressing, Part II: Scaling IPv4 Across the Internet DevFeed: [IP Addressing, Part II: Scaling IPv4 Across the Internet]() Original publisher: [Read original article]() Author: Franco Fernando Published: 2026-08-01T11:36:30Z Content type: article Language: en Sources: [The Polymathic Engineer]() Topics: [Internet]() Tags: [internet](), [ip](), [ipv4](), [nat]() ### AI overview This article explains how CIDR replaced classful addressing and how private addresses and NAT helped extend the usable life of IPv4. ### Source excerpt How classful addressing gave way to CIDR, and how private addresses and NAT kept the world from running out of IPv4. ## 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). ## Self-service peering with a PeeringDB login DevFeed: [Self-service peering with a PeeringDB login]() Original publisher: [Read original article]() Author: Bastiaan Brink Published: 2026-07-27T00:00:00Z Content type: opinion Language: en Sources: [AS215248 - Notes]() Topics: [Networks](), [OAuth](), [Server]() Tags: [automation](), [bgp](), [dashboard](), [ipv4](), [ipv6](), [ixp](), [login](), [mail](), [networks](), [oauth](), [peering](), [permission](), [request](), [self-service]() ### AI overview The article describes a self-service peering portal that uses PeeringDB OAuth to authenticate users, verify ASN update rights, and offer exchanges where both networks are present. Requests create disabled sessions for manual approval, with inherited filtering and validation policies, notifications, and approval-based removal. ### Source excerpt Peering requests used to be mail ping-pong. Now you log in with PeeringDB on the peering page, pick an exchange, and the session is waiting for my approval. ## The Anatomy of an IPv4 Address (Part I) DevFeed: [The Anatomy of an IPv4 Address (Part I)]() Original publisher: [Read original article]() Author: Franco Fernando Published: 2026-07-25T10:00:35Z Content type: tutorial Language: en Sources: [The Polymathic Engineer]() Topics: [Network]() Tags: [ipv4](), [network]() ### AI overview This tutorial explains how an IPv4 address is structured, what a subnet mask does, and how a device determines which network it belongs to. ### Source excerpt How an IPv4 address is built, what a subnet mask does, and how a device determines the network it belongs to. ## What's ARP Got to Do with It? DevFeed: [What's ARP Got to Do with It?]() Original publisher: [Read original article]() Author: Remco van Mook Published: 2026-07-23T06:35:41Z Content type: article Language: en Sources: [RIPE Labs]() Topics: [Internet](), [Network](), [Networks](), [FIRST]() Tags: [arp](), [article](), [enterprise](), [ietf](), [internet](), [internet-infrastructure](), [ipv4](), [network](), [networks]() ### AI overview The article examines why ARP still matters by distinguishing durable demand for IPv4 reachability from the local-network architecture traditionally used to provide it. It argues that many access and hosting segments isolate subscribers or tenants and use the local IPv4 subnet mainly as a mechanism for reaching the gateway, rather than for lateral communication. ### Source excerpt It's only ARP. It works. So how much can it really matter? The answer lies beyond ARP itself, in the IPv4 layer cake that grew around it over four decades. The IPv4 internet is not going away in bounded time, and nobody should pretend otherwise. ## RFC8950: Announce IPv4 with an IPv6 next-hop DevFeed: [RFC8950: Announce IPv4 with an IPv6 next-hop]() Original publisher: [Read original article]() Published: 2026-06-22T08:34:09Z Content type: tutorial Language: en Sources: [Personal blog of Anurag Bhatia]() Topics: [BGP]() Tags: [bgp](), [frr](), [ipv4](), [ipv6](), [rfc8950]() ### AI overview A tutorial-style explanation of RFC8950, which enables IPv4 routes to use IPv6 next hops over MP-BGP sessions. It describes IPv6-only backbone use cases, explains that the change affects the control plane while IPv4 remains unchanged on the wire, and outlines a Container Lab demonstration using FRR. ### Source excerpt For the last few days I have been playing with RFC8950 setup, which allows routing of IPv4 on top of IPv6. While logically it's quite simple, it has a very powerful application towards making "IPv4 an optional" feature riding on top of an IPv6 network (but without any tunnels!) Some of the interesting use cases: A large network can run IPv6 only everywhere on its core and leave IPv4 only on edge devices. This can work without customers doing any tweaking at their end. They still do things the old way but Backbone can run IPv6 only at its core. An IP transit backbone can run IPv6 only while exchanging IPv4 routes with its customers/peers/upstream over IPv6 sessions. So IPv4 as a "feature" stays but the network in itself is IPv6 only without the overhead of IPv4 interface config, BGP session config, firewall config, etc. An IXP can offer services without IPv4 essentually by using a (unique) IPv6 at the IX LAN & running route server to exchange both IPv4 & IPv6 routes over the IPv6 only session. Thus what 464XLAT did to the mobile networks - this has the potential to do that for the backbone networks. How does it work? Multi-protocol BGP (MP-BGP) supports announcement of IPv4 routes over IPv6 sessions with IPv4 next-hops and IPv6 routes over IPv4 sessions with IPv6 next-hops. RFC8950 extends this feature for IPv4 to have IPv6 next-hops. So for IPv4 address, next hop is IPv6, IPv6 reach works via usual NDP and IPv4 rides on ethernet frames to the same MAC as discovered by the NDP. Technically RFC8950 only impacts control plane decisions by using IPv6 as the control plane but keeps the data plane as it is. IPv4 stays IPv4 & goes as IPv4 over the wire unlike say some tunnel or 464xLAT etc. Hardware support As of now it's quite widely supported by a lot of routing platforms like Juniper JunOS, Cisco IOS XR, Nokia SR OS, Mikrotik, Huawei, BIRD, FRR etc. So, it is very likely supported if you are running a recent version of the OS. Demo lab Here's a fun lab with two customer ## Rust smoltcp as an alternative TCP/IP stack for ESP-IDF DevFeed: [Rust smoltcp as an alternative TCP/IP stack for ESP-IDF]() Original publisher: [Read original article]() Author: John Lee Published: 2026-06-19T00:00:00Z Content type: tutorial Language: en Sources: [Blog on Developer Portal]() Topics: [ESP-IDF](), [Rust](), [networking](), [ESP32](), [ESP32-P4](), [HTTP](), [MQTT]() Tags: [blog](), [c](), [concurrency](), [esp-idf](), [esp32-p4](), [ethernet](), [firmware](), [http](), [http-server](), [ipv4](), [ipv6](), [lwip](), [mqtt](), [networking](), [rust](), [smoltcp](), [tcp-ip](), [tls]() ### AI overview This article explains how to run the Rust smoltcp TCP/IP stack as an alternative IPv4/IPv6 data plane under ESP-IDF. It describes a GNU linker --wrap shim that preserves compatibility with ESP-IDF networking components such as esp_http_server, esp-tls and esp-mqtt, along with the single-task poll architecture, measured ESP32-P4 throughput, and known limitations. ### Source excerpt A set of ESP-IDF components that run the Rust smoltcp stack as the IPv4/IPv6 data plane, while keeping esp_http_server, esp-tls and esp-mqtt working without source changes. This article explains the linker -wrap shim that makes it compatible, the single-task poll architecture, the throughput I measured on an ESP32-P4 (91.15 Mbit/s on a 100 Mbit link), and the limitations to be aware of. ## 20 Networking Concepts Explained in 15 Minutes DevFeed: [20 Networking Concepts Explained in 15 Minutes]() Original publisher: [Read original article]() Author: Ashish Pratap Singh Published: 2026-06-02T05:28:43Z Content type: tutorial Language: en Sources: [AlgoMaster Newsletter]() Topics: [networking](), [Networks](), [domain](), [Internet](), [browser](), [HTTP]() Tags: [browser](), [concepts](), [dns](), [domain](), [http](), [https](), [ipv4](), [ipv6](), [mac-address](), [network](), [networking](), [postgresql](), [recursive-resolver](), [redis](), [ssh](), [wi-fi]() ### AI overview A tutorial introducing core networking concepts, including IP addressing, DNS resolution, ports, MAC addresses, and ARP, with examples involving browsers, routers, servers, SSH, HTTP, PostgreSQL, and Redis. ### Source excerpt Networking can feel overwhelming, but a small set of concepts carries most of the weight in interviews and real-world systems. ## 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 ... ## Generate Partial Device Configurations with netlab DevFeed: [Generate Partial Device Configurations with netlab]() Original publisher: [Read original article]() Published: 2026-04-30T05:26:00Z Content type: tutorial Language: en Sources: [ipSpace.net blog]() Topics: [Network](), [configuration](), [BGP](), [IS-IS]() Tags: [bgp](), [configuration](), [files](), [how-to](), [ipv4](), [ipv6](), [management](), [netlab](), [network](), [networks]() ### AI overview This tutorial explains how to use netlab to generate a wiring plan, IP addressing plan, reports, and partial device configuration files for a physical multi-vendor network lab. It also describes adding configuration modules and deploying configurations through an out-of-band management network. ### Source excerpt At ITNOG 10, I've seen something that I haven't seen in a very long time: a mini-Interop-style physical lab using a dozen devices from different vendors. The network core was a leaf-and-spine fabric with off-path BGP route reflectors and numerous other devices attached to it. I've configured a few networks in the past, so I know it must have been a beast to configure all those devices by hand (and fix all the IP addressing errors), but then a thought struck me: unless one wants to practice configuring IP addresses, it might be a good idea to use netlab to generate the IP addressing plan and partial device configurations. Read more ... [Next page]()