1. My Core Exploded And All I Got Was This Lousy T-Shirt
Vijay Gill

2. What Is The Problem The amount of state is increasing. Real problem
So what?
Real problem
Nasty surprises that result from interactions between current routing implementations, increased state, CPU, and message processing.

3. Examples Run to completion processing may cause missed hellos
Frame Relay meltdowns
Time diameter exceeds hold down
Pegged CPU on primary causes slave to initiate takeover
Decoupled Hello processing from Routing Process

4. Types of State Amount of state is approximately the same
Where it is and how the protocols deal with it are different
Lean IGPs
Reasons for Lean IGP
Carry Prefixes in iBGP
Primary state growth is in BGP
Focus on BGP

5. Prefixes in a Promising Local ISPs Network

6. Resource Consumption # of Paths vs. # of Prefixes
Large amounts of peering
Crunch RIB to populate FIB
More state requires more CPU time
Delayed Convergence

7. RIB

8. FIB

9. Insufficient Resources
Memory Fragmentation
Solved Problem – Hope springs eternal
Flap BGP Sessions
Failure cascade
Packet forwarding and downstream peering failures
Learned Routes
Forwarding Table

10. Route Establishment

11. Growth Trends RIB Growth is Linear FIB Growth is Sub-linear
RIB has multiple views/paths
FIB only has the Forwarding Table
Regardless of the number of paths/routes, only few forwarding entrys are installed in the FIB

12. Scaled RIB/FIB Memory Usage
Time
Money

13. Results Headroom seems to consist of 100k more prefixes
Supra-linear growth trend
Two years: Consumption /14 every 4 months or so.
Today, less than 2 months.

14. Peer Updates

15. This is a problem Transient routing loops
Potential for wide scale disruption of routing functionality
Missed Keepalives
May never Converge
Choke point is updating peers

16. RIP V2 Forever!
Questions and Answers