Dynamic AS renumbering

1
Dynamic AS renumbering

• draft-hares-bose-dynamic-as-01.txt
• draft-hares-Confed-Edge-AS-01.txt
• Susan Hares
• Pratik Bose
• IETF 63

2
AS Confederation Topology
3
Fall back to AS 6505
Allow connections through other node
4
Fail-over at edge of AS

• Allow AS 6505 to drop out of confederation
  without dropping peers
• Open exchange sets it up
• Negotiate change with all IBGP peers
• Dynamic capability switches a peer between AS 10
  and AS 6505
• Can also switch peer back to AS 10
• Dont drop peers associated with AS 6505
• Dont drop 500, 501, 502

5
Open Capabilities
Dynamic AS
AS Confederation
Length of AS (1)
Length of AS (1)
Send prefix flag (1)
Send prefix flag (1)
Number of AS (1)
Number of AS
AS Confederation
Original AS
AS 1
AS 1
AS 2
AS 3
0x00 Resend routes based on local timer (in
batches) 0x01 Resend routes immediately 0x02
Dont resend routes
6
Dynamic Capabilities
AS Confederation
Dynamic AS
Length of AS (1)
Length of AS (1)
S
F
C
RR
Resend Flags
S
F
C
RR
Resend Flags
AS Confederation
Number of AS
AS 1
Original AS
AS 2
AS 1
AS 2

• S Source (EBGP/node)
• F Failure(1)
• C Confederation
• RR 2 bits reserved
• Resend flags 3 bits (0 timer, 1 immediate, 2
  never)

AS 3
7
Dynamic Exchanges
Open with capability
Open with capability
Keepalive
Keepalive
Updates
Updates
Dynamic Capability new AS
Dynamic Capability New AS
Updates
Updates
8
Feedback from Last November

• Con
• Sounds like something that should be configured
• Notification of IBGP (normal RR) peers for
  synchronization
• Remove Security cookie
• Pro
• Solves certain networks problems
• Dynamic Capabilities new draft provides ack

• Whats new
• Simplified Open Dynamic Capability message
• Dynamic AS renumber for any AS
• IBGP peers notified confirmed prior switch

9
Next Steps

• Implementation testing in August/Sept
• Test with projected network scenarios measure
  convergence time
• 10s, 100s, 1000 peers to Confederation
• Various Route Mixtures with v4 and v6
• Various resend prefix flags (never, timer based,
  immediate)
• Test interaction with IGPs
• OSPF(v2/v3) OSPF MANET
• ISIS
• Get further feedback on deployment scenarios
• Love any more feedback from working group