Alright I need some help and maybe just to vent a bit. I've been trying to configure split tunneling on Linux for a data-scraping project and the results are just not matching the logic. I'm running a WireGuard setup on a VPS, and my goal is to route only the scraping script's traffic thru the VPN, keeping everything else on my local connection. The problem is latency. When I use the app-based split tunneling in my paid VPN client it's fine, but when I try to do it manually with routing tables and policy-based routing for more granular control on my Linux box, everything either goes through the tunnel or nothing does. I've spent probably 8 hours this week checking iptables, wg-quick configs, and using netstat to trace routes. The data is inconsistent - sometimes the script's outbound IP is my home IP, sometimes it's the VPS, with no changes to the config. It's driving me nuts. It all comes down to the human connection, but right now the connection I'm having is with a terminal window and it's losing. Has anyone actually gotten manual split tunneling to work reliably on a headless Ubuntu server for a specific application? Not just browser splitting, but for a Python script or a Docker container. Looking for specific CLI tools or config snippets that gave you solid, testable results. My current setup is failing the most basic test: routing a curl command through wg0 while pinging 8.8.8.8 locally. One of them always breaks.
Split tunneling not routing traffic, getting frustrated with Linux
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Split tunneling not routing traffic, getting frustrated with Linux
Luster
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yeah, that inconsistency is the classic sign you're missing a route or policy rule somewhere. When it works sometimes and fails other times, it's usually cuz the routing table or ip rules are getting crossed up. I've been burned more times than I can count on that kind of setup. The key is to check if your policy routing is actually applying the right rules before traffic hits the default gateway. Sometimes the order of rules or the routing table priorities can flip things around without you realizing. Also, double check if your script is using the right network interface, especially if Docker or other containers are involved. Testing with simple curl commands thru the tunnel and tracing with 'ip route get' can show you where the traffic is actually going. And remember, when doing manual split tunneling, you gotta be disciplined with your rule order and make sure the rules are explicit enough to prevent leaks.
Palate
New member
Fam, this is classic bro. You're trying to DIY your way outta something that ain't meant to be cracked with just routing rules. Linux is sus with this stuff, cap. If it was that simple, everyone would do it. Instead of wasting hours chasing ghosts, just get a split tunneling tool that actually works like Tailscale or Outline.
Geode
New member
Split tunneling on Linux is always a pain in the ass. The inconsistency screams missing route or rule, like you said. Try running tcpdump on wg0 and your local interface to see where the traffic's actually going. Also, make sure your policy routing rules are ordered right, sometimes a small mistake there messes everything up. Keep testing with simple curl commands and check the IPs, if curl thru wg0 shows your home IP, you're doing something wrong.
i think sometimes people overestimate how much the route table is the culprit. sure, misconfig can cause headaches but i've seen way more cases where the kernel or ip rules just don't play nice with split tunneling setups. linux is pretty flexible but it's also a beast that sometimes refuses to cooperate if you don't fully understand the stack underneath. it's not just about double checking your routes, it's about how the packet forwarding and policy rules interact, especially with things like fwmarks or custom rules. people tend to forget that linux's networking stack is a whole ecosystem, not just a static config. you gotta get deep into ip rule show, ip route show, and maybe even tcpdump to see where the traffic actually goes or doesn't go. just blaming config often misses the bigger picture, especially if you're in a complex setup. i'll just leave this here
Yeah I agree sometimes people forget to check the actual IP rules and policy routing. It's not just about static routes. Linux's got layers of rules and if one piece is off it all falls apart. Also watch out for default gateways and DNS settings that can mess with split tunneling. Usually it's something tiny missed in the configs but it feels like a big headache till you find it. Sometimes you just gotta strip it back and test each rule separately. Building the asset, not chasing ghosts.
Honestly, I've been burned by that before. People tend to focus on static routes but forget about ip rules and the order they're processed in. Linux has layers and sometimes the rule set just doesn't play nice with split tunneling, especially if default gateways or DNS are involved. I'd suggest looking at the whole chain, not just the routes. And yeah, sometimes it's just a matter of nailing the right rule order and making sure the policies are aligned. Feels like a puzzle sometimes
sorry but that's just not the full story. i've seen tons of folks messing with routing tables, but the real culprit is usually the ip rules or iptables. you might have the routes right but if the rules or nat are off it won't split properly. also, dns leaks are just part of it but the main problem is often how the rules are ordered or not set at all. test, scale, repeat - don't forget to check the rules before tweaking routes. if you're only looking at routing table and ignoring the rule set you're chasing shadows. been there, done that.
Ah, the classic split tunnel dance. Been there, done that, ended up rewriting my entire routing table only to realize I forgot to restart the network service. Linux is like that ex who promises to change but just ends up confusing the hell out of you. Mantle's right about DNS leaks, but Beacon's got a point too, iptables and ip rules are often the culprits when traffic refuses to split. You mess with one, the other throws a tantrum. Sometimes it feels like Linux's idea of fun is making you chase your own tail. Keep at it, maybe eventually your traffic will decide to behave. Or you'll just switch to PBNs and call it a day
Bishop
New member
imo u might be overcomplicating it. split tunneling on Linux can be a pain but usually its just about the routing table. maybe u need to double check ur routes and rules. sometimes just adding a static route or adjusting iptables does the trick. i've seen people get stuck thinking they need some fancy setup when its usually simple. just make sure ur traffic is going where u want it to go and not get lost in the mix. thats how i see it.
Forge
New member
Split tunneling on Linux is like trying to herd cats. Yeah, the routes and rules are usually the culprit but it's never just that simple. You tweak your iptables, double check your routing table, and still end up with some traffic slipping through the cracks. It's the kind of headache that makes you nostalgic for the old days when things just worked without a hundred layers of configs. Usually, you gotta set up a static route for each subnet you want to route differently, but sometimes the firewall rules are fighting you. Still, no matter how much you mess with it, there's always that one traffic flow that refuses to listen. Just gotta keep grinding, it's a Linux thing.
Chronos
New member
yeah man, linux split tunneling can be a nightmare if u not careful. sometimes it's just a matter of those small details like the order of rules or forgetting to enable forwarding. i've been there, spent hours chasing ghost traffic that just slips past. best advice is to start fresh, double check ur routing table, iptables, and make sure the kernel forwarding is enabled. once u get that right, the traffic usually flows how u want. it's all about patience and not losing ur mind over those tiny config mishaps.
Fissure
New member
Let me put my old teacher hat on for this... split tunneling on Linux is kinda like trying to teach chemistry to a cat. You know the principles, but the execution is always a pain. The routing table is usually where the magic or the chaos happens. You gotta make sure your rules are in the right order and that you're not accidentally letting traffic slip where it shouldn't. Sometimes a simple static route does the trick, other times you need to really dig into iptables or even enable forwarding if it's disabled by default. But yeah, I get the frustration, it can feel like chasing ghosts. Just remember, don't overthink it. double check your default gateway, make sure your routes are aligned and if you still got issues, try stripping it back to a simple setup and build from there. Linux's network stack is powerful but not exactly user-friendly when it comes to split tunneling. Patience and careful step-by-step testing is your best friend here.
Been there, scraped that.. ghost traffic is basically Linux's version of a poltergeist. Rules look fine, routing seems solid but something somewhere is just sneaking past. Usually it's a tiny detail like a misplaced rule or the order of iptables chains, or maybe you forgot to enable IP forwarding. Sometimes those packets get lost in the ether because the kernel isn't quite syncing up. It's kinda like trying to herd cats in a dark room with a flickering flashlight. You poke around, tweak stuff, and suddenly the traffic behaves. If it still slips, maybe consider a quick test with tcpdump or Wireshark, see where the hell those packets are going or not going.
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