Building a Multi-Site MikroTik Network with OSPF

Overview

OSPF (Open Shortest Path First) is the go-to dynamic routing protocol for enterprise multi-site networks. This guide walks through deploying OSPF across MikroTik routers at multiple branch offices.

Prerequisites

• MikroTik RouterOS 7.x
• Site-to-site connectivity (MPLS, VPN, or leased lines)
• IP addressing plan with /30 links between routers

Basic OSPF Configuration

# Enable OSPF instance on RouterOS 7
/routing ospf instance add name=main router-id=10.0.0.1

# Create OSPF area
/routing ospf area add name=backbone instance=main area-id=0.0.0.0

# Add network interfaces to OSPF
/routing ospf interface-template add area=backbone interfaces=ether1 type=ptp
/routing ospf interface-template add area=backbone interfaces=lo0 type=stub

Multi-Area Design

For larger deployments, use multiple OSPF areas to reduce LSA flooding:

• Area 0 (Backbone): Core routers and inter-site links
• Area 1 (Branch offices): Stub areas for branch LANs
• Area 2 (DMZ): NSSA for internet-facing segments

# Configure stub area for branch
/routing ospf area add name=branch1 instance=main area-id=0.0.0.1 type=stub

Route Summarization

Summarize branch prefixes at ABRs to reduce routing table size:

/routing ospf area-range add area=branch1 prefix=192.168.10.0/23 advertise=yes

Authentication

Always enable MD5 authentication between OSPF neighbors:

/routing ospf interface-template set [find] auth=md5 auth-key=YourSecureKey123

Verification

/routing ospf neighbor print
/ip route print where routing-mark~"ospf"
/routing ospf lsa print

Best Practices

1. Use loopback interfaces as router-IDs for stability
2. Enable BFD for sub-second failure detection
3. Set reference bandwidth to match your fastest links
4. Document all area boundaries and summarization points
5. Test failover by physically disconnecting a link — not just shutting it down

OSPF on MikroTik is production-ready and scales well to 20+ sites. Keep your area design simple and your authentication consistent.