OpenWrt on Jaymin Patel

5 Lessons from Building SD-WAN Products

Tue, 02 Jun 2026 12:00:00 +0530

After 18 years building networking products -- from UTM firewalls at Cyberoam to wireless controllers at Sophos, and now SD-WAN solutions at Elemprin -- here are five lessons that shaped how I think about product development.

1. The Kernel Is Your Foundation Link to heading

At Red Piranha, we upgraded the Linux kernel from 3.10 to a modern version. This wasn't just a version bump -- it required porting years of custom patches, building a unified config across platforms, and repackaging everything as RPMs. The lesson: invest in your kernel strategy early. A clean, maintainable kernel tree pays dividends every release cycle.

High Availability on OpenWrt with Keepalived, UCI, and LuCI

Thu, 08 Sep 2022 00:00:00 +0530

When a router goes down, the network goes down. For homes, it's an annoyance. For businesses, it's lost revenue. Keepalived solves this by implementing VRRP (Virtual Router Redundancy Protocol) -- two or more routers share a virtual IP. If the master fails, the backup takes over in seconds.

I contributed Keepalived integration to OpenWrt across three areas: the core package improvements, a UCI configuration layer, and a LuCI web interface.

IPSec VPN on OpenWrt: From Config Files to UCI

Mon, 22 Aug 2022 00:00:00 +0530

Setting up an IPSec VPN on OpenWrt used to mean editing /etc/ipsec.conf by hand -- tracking down the right parameters for your topology, debugging misconfigured secrets, and restarting the service after every change. For site-to-site tunnels between branch offices, or road-warrior access for remote employees, the manual approach worked but didn't scale.

Libreswan, the IPSec implementation used in OpenWrt, is a battle-tested VPN stack. But until now, it lacked the configuration layer that makes OpenWrt's ecosystem so powerful: UCI (Unified Configuration Interface). With UCI support, Libreswan joins the rest of OpenWrt's services -- configurable through a consistent interface, scriptable for automation, and manageable at scale.

Real-Time Network Monitoring with Apinger on OpenWrt

Wed, 06 Jul 2022 00:00:00 +0530

When your network link goes down, every second counts. Whether you're running a home office with a cable modem and cellular backup, or managing a multi-WAN enterprise router, you need to know the moment a connection fails -- and you need the system to respond automatically.

Apinger gives you that capability. It's a lightweight alive-monitoring daemon that pings multiple targets across different interfaces and triggers configurable alarm actions when links degrade or fail. With the new UCI and LuCI integration, setting it up takes minutes.

Persistent SSH Tunnels with Autossh and UCI on OpenWrt

Mon, 04 Jul 2022 00:00:00 +0530

SSH tunnels are the Swiss Army knife of network connectivity. Need to access a device behind NAT? Reverse tunnel. Want to secure traffic over an untrusted network? Local forward. Managing remote routers from a central jump host? Multiple tunnels, multiple ports.

The problem with SSH tunnels is that they die. Network blips, ISP maintenance, DHCP lease renewals -- any interruption kills the connection and the tunnel goes down. Manually SSH-ing back into a remote router to re-establish tunnels doesn't scale past a handful of devices.