Static Routing Versus BGP for WISPs
When static routes are enough, when you need BGP, and what a growing WISP should plan for.
Every WISP starts with static routes: a default gateway points to the upstream provider, and traffic flows out. It is simple, predictable, and easy to troubleshoot. But as you add redundancy, multiple upstream providers, or your own IP space, static routing becomes a liability.
This article explains when static routes are enough, when you need BGP, and what the transition looks like.
Static routing: simple and predictable
With static routing, you manually configure each route on your router. A typical WISP tower has:
- A default route pointing to the upstream provider
- Static routes for locally connected subnets
- Maybe a floating static route for a backup default gateway
Static routing works well when you have one primary provider, no public IP space of your own, and simple failover requirements.
BGP: necessary for multi-homing
Border Gateway Protocol becomes necessary when you want to:
- Announce your own public IP space to multiple providers
- Load-balance or fail over between two upstreams automatically
- Influence inbound path selection
- Receive full or partial internet routing tables
- Peer directly with content networks or other carriers
When to make the switch
| Situation | Recommendation |
|---|---|
| Single upstream provider | Static routes |
| Two providers, no owned IP space | Static + floating default routes |
| Two providers, own IP space | BGP |
| Need inbound traffic engineering | BGP |
| Peering with other networks | BGP |
What you need for BGP
- An Autonomous System Number (ASN) from your regional registry
- Your own public IP address space (or a Letter of Authorization from your provider)
- A router that supports BGP and can handle your chosen routing table size
- Upstream providers willing to peer with you
- Someone on your team who understands BGP routing policy
Need routing design help?
SmashByte Wireless helps WISPs design static and BGP routing, request ASNs and IP space, and configure redundant failover.
Talk to a Network Engineer