Here's when to use each protocol:
Use RIP when:
- Network is small (under hops)
- Simplicity matters more than efficiency
- Legacy equipment requires it
Use OSPF when:
- Network spans multiple vendors
- You need hierarchical design with areas
- Standards compliance is required
Use EIGRP when:
- Network is primarily Cisco equipment
- You need fast convergence
- Flexible summarization is needed
In practice, OSPF dominates enterprise networks due to vendor neutrality. EIGRP is common in Cisco-only environments. RIP is mostly found in legacy systems.