1. Network Router Configuration: From Data Mining to Policy Management
Context
Proposition
Comparison with other approaches
State of the effort
Next steps

2. Context
IPeFR
ARACS?
Tools
Configs
DBMS
Config Updates
Routers

3. What We Learned Configuration errors are common
Error correction record is mixed
Vendor dependence causes problems
Automation is good

4. What Is the Problem
Much of configuration is still manual (how much cut & paste is involved?)
Those managing configurations have limited time
Vendor expertise seems to be required for too much of provisioning management
Many configuration errors are benign

5. Why Should We Care Some configuration errors are NOT benign
The network is becoming more complex
The business is highly competitive
Having the ability to manage routing policy in isolation may make us more responsive to our customers

6. Proposition
Data model that stores pure policy (or as pure as we can make it)
Compose complex policies as a composition of policy atoms
Isolate vendor dependencies as much as possible

7. Proposition
Manage BGP Attributes with tables giving them names and descriptions
Names could be chosen by marketing
Autogenerate policy documentation
Manage Private AS allocation
Use current address space management to generate customer specific prefix lists

8. Example CUST-FACE route map Deletes updates containing:
Default routes, Loopback addresses, Martians
Reserved Community Values
Peers, private AS’s, Confederations in AS Path
Applies a mixture of:
Local Preference Policy
Route Scope Policy

9. Filter route-map CUST-FACE deny 10 match community 105
! 0:611 (0|7018):
route-map CUST-FACE deny 20
match ip address prefix-list CF-martians
! Default route, loopback, martians
route-map CUST-FACE deny 30
match as-path 99
! Delete routes with as-paths containing peers,
! private AS’s, and Confederations

10. Communities only route-map CUST-FACE permit 100
match community 109 ! 7018: :20
set local-preference 90
set community 0: :2000 additive !
route-map CUST-FACE permit 102
match community 108 ! 7018: :20
set local-preference 80
route-map CUST-FACE permit 104
match community 107 ! 7018: :20
set local-preference 70

11. Add Address Matching route-map CUST-FACE permit 130
match ip address prefix-list CF-CIDR ! AT&T Addresses
match community 139 ! 7018:90
set local-preference 90
set community 0: :2010 additive !
route-map CUST-FACE permit 132
match community 138 ! 7018:80
set local-preference 80

12. route-map CUST-FACE permit 140
match community 149 ! 7018:90
set local-preference 90
set community 0: :2000 additive ! Default is to advertise !
route-map CUST-FACE permit 142
match community 148 ! 7018:80
set local-preference 80
set community 0: :2000 additive
route-map CUST-FACE permit 144
match community 147 ! 7018:70
set local-preference 70
route-map CUST-FACE permit 146

13. Community Table
name value scope description
ATTAGG : I Aggregated AT&T-owned addresses
ATTAGG : I Aggregated AT&T-owned addresses
ADVERTISE : I Non ATTAG routes with external visibility
ADVERTISE : I Non ATTAG routes with external visibility
NOEXPORT : I AT&T no-export community
NOEXPORT : I AT&T no-export community
NOPEER : I Routes not to be announced to peers
NOPEER : I Routes not to be announced to peers
NOCINFRA : I NOC infrastructure
NOCINFRA : I NOC infrastructure
NOCVIS : I Networks that must be visible to the NOC
NOCVIS : I Networks that must be visible to the NOC
PEER : I Routes learned from peers
PEER : I Routes learned from peers
EADV : E Client advertise request

14. Other Tables Resource Tables BadPrefixSpace RsrvdCommunitySpace
MartianSpace
LocalSpace
LocalAS
PeerAS
Community
ExtendedCommunity
Composition Tables
CommunityCommunityIn
CommunityCommunityOut
CommunityPref
PrefixCommunity
AtomicTransformations
CompositeTransformations

15. Benefits of This Approach
We can reason about and manage policy directly
Change policy and let the tools generate vendor dependent configurations
Vendor Independence more easily accomplished

16. Policy
BGP policy expert
Vendor A
Vendor B

17. State of the Effort Vaporware alert We have some preliminary tables
We will be starting on a tool to generate Cisco configurations very soon

18. What’s Next Tools for configlet generation?
Tools for some other vendors router?
Yet another routing policy language?

19. Acknowledgements Joel Gottlieb Albert Greenberg Tim Griffin
Harmen Van Der Linde