1. Running Multiple XORP Instances
In One Box
Jiaqing Du

2. Outline
• Introduction
• XORP Overview
• Running XORP
• Configuring XORP
• Experiment
• Conclusion

3. Introduction
• XORP
– eXtensible Open Router Platform
– Why reinvent the wheel?
• Vision of authors
– Why the Internet only just works
• Vision of MX
– Control plane of Internet-in-a-lab
• Vision of others
– Intel Research
– Vyatta Inc.

4. XORP Overview
Control Plane
Data Plane

5. Running XORP (1/2)
• Virtual network interface
– VLAN on Linux (802.1q kernel module)
– Supported by XORP
– Almost the same as physical interfaces
• Port conflicts
– Finder: 127.0.0.1:19999
– OSPF: raw socket
– BGP: 179

6. Running XORP (2/2)
• OSPF traffic
– Multicast packets
– TTL = 1, dst = 224.0.0.5
– setsockopt(), IP_MULTICAST_LOOP
OSPFv2 OSPFv2
XORP0 XORP1
Virtual NIC
Physical NIC

7. Configuring XORP
• Input
– xml file describes network topology
• Intermediate
– Ruby objects
– AS, router, interface, link
• Output
– XORP configuration files
– startup and shutdown shell scripts

8. Experiment (1/2)
• Topology from VINI
– 11 OSPF routers in a AS

9. Experiment (2/2)
• Another topology
– Multiple ASes
– Routes redistribution
AS2
AS0
AS1

10. Conclusion
• Deliverable
– Slightly patched XORP-1.5
– Configuration scripts
• Learned
– How a router works
– How routing protocols really work

11. Questions?