Second internet line works sometimes, sometimes not
Load balancing without session affinity flips connections mid-flow. Lethal for TLS and VPN.
Try this first
- 1Check on your router whether dual-WAN runs at packet or session level. Packet-level breaks most apps, session-level (sticky) is what you want.
- 2For traffic that must always go via one line (VoIP, VPN, ERP), set a policy-based route. That overrides the load balancer for specific destinations.
- 3Test with a continuous ping and a file download in parallel. If the download stalls without ping loss, you flipped WANs mid-stream.
- 4Failover-only is calmer than load balancing: line 1 active, line 2 reserve. That is what most SMB offices actually meant.
When to bring us in
Multi-WAN with BGP or SD-WAN sits outside DIY scope. If one line is fibre and the other 4G/5G, we can build a simple, reliable failover set.
See also
- Wi-Fi drops randomly across the officeFirst rule out whether it is the access points or the internet connection itself. Different fix.
- One room or corner has no or bad Wi-FiNot always "add another AP"; often one is poorly positioned, or there is a metal wall in the way.
- Internet is suddenly slow for everyoneThree suspects: your provider, a colleague soaking the line, or a backup or update kicking in unexpectedly.
None of the above fits?
Describe your situation below. We pass your input plus the steps you already saw to our AI and return tailored next-step advice. If it's too risky to DIY, we'll say so.
Or skip the DIY entirely
Our Managed IT clients do not look these things up. One point of contact, a fixed monthly price, resolved within working hours.