Securing dynamic routing protocols (like BGP, OSPF, EIGRP, RIP, etc.) is crucial to maintaining the integrity and stability of a network. These protocols were not originally designed with strong security in mind, so network engineers must apply a combination of authentication, filtering, and policy controls to mitigate threats like route hijacking, spoofing, and DoS.
Here's a breakdown of how to secure the most common dynamic routing protocols:
π 1. Authentication
β OSPF, RIP, EIGRP (Interior Protocols)
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Use MD5 or SHA authentication on routing updates to ensure only trusted routers participate.
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Example (OSPF):
β BGP
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Use TCP MD5 authentication (
neighbor x.x.x.x password
) or TCP-AO (Authentication Option) for session protection. -
Example (Cisco):
π Purpose: Prevents unauthorized peers from forming sessions and injecting routes.
π§± 2. Access Control / Filtering
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Passive Interfaces: Disable routing protocol advertisements on interfaces that don't need them.
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Route Filtering: Use prefix-lists, distribute-lists, and route-maps to control what routes are sent or received.
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Interface ACLs: Apply access control lists to limit routing protocol traffic to trusted IPs only.
π 3. Control Plane Protection
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Use Control Plane Policing (CoPP) or Control Plane Protection (CPPr) to throttle or restrict routing protocol traffic (especially for BGP on edge routers).
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This prevents CPU exhaustion from routing protocol floods or malformed packets.
π 4. TTL Security / BFD
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TTL Security Hack (GTSM) for BGP:
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Ensures that only neighbors within one hop can establish a session.
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Mitigates TCP spoofing and off-path attacks.
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BFD (Bidirectional Forwarding Detection):
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Provides fast failure detection for dynamic routing sessions.
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π 5. Monitoring and Logging
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Enable logging for neighbor state changes and route updates.
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Use SNMP or NetFlow to monitor for anomalous routing activity.
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Use tools like BGPmon, RIPE RIS, or RPKI validators for BGP monitoring and route validation.
π§© 6. Use RPKI and BGP Prefix Validation (for BGP)
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Deploy RPKI (Resource Public Key Infrastructure) to cryptographically validate BGP route origin.
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Prevents route hijacking by dropping invalid prefixes.
π° 7. Segment and Harden the Routing Infrastructure
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Limit physical and logical access to routers.
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Apply least privilege principles and secure router credentials (no default passwords).
β Summary Table
Security Measure | Protocols | Purpose |
---|---|---|
MD5/SHA Authentication | BGP, OSPF, RIP | Peer validation |
Route Filtering | All | Prevent route leaks/attacks |
CoPP/CPPr | All | CPU protection |
RPKI | BGP | Origin validation |
TTL Security (GTSM) | BGP | One-hop neighbor validation |
BFD | All | Fast failure detection |
Logging & Monitoring | All | Audit and alert |
Passive Interfaces | OSPF, RIP, EIGRP | Reduce exposure |