PIM Extension For Tunnel Based Multicast Fast Reroute (TMFRR)

draft-lwei-pim-tmfrr-00IETF 76, Hiroshima

Motivation

• Protect native IP multicast and GRE mVPN traffic

• Protect against both link and node failures• Allow multiple tunneling technologies

– RSVP/TE, LDP, GRE etc…• Support MoFRR behavior

IETF 76 2draft-lwei-pim-tmfrr-00

TMFRR Overview• Backup tunnel is pre-built• When failure occurs, traffic is

redirected around the failed link or node via the TMFRR tunnel

– MoFRR mode is also supported

• MP accepts packets from both native interface and TMFRR tunnel

• Signaling between MP and PLR is done via PIM extension.

IETF 76 3draft-lwei-pim-tmfrr-00

ASrc B

C

Rcvx y

TMFRR Tunnel

Link Under Protection

Router A: Pointer of Local Repair(PLR)Router B: Merge Point (MP)

TMFRR Inner Label

• The MP assigns label X from its own label space.• Upon Traffic reroute, PLR pushes label X

(assigned by MP) as inner label of packet and sends through a tunnel.

• On MP, packets with label X are accepted, as alternative to RPF interface check.

• Backup tunnel can be set up by RSVP-TE or any other tunneling mechanism.

IETF 76 4draft-lwei-pim-tmfrr-00

PIM Extension

• New PIM Hello option for MP to notify PIM neighbors of backup label X, and router ID over RPF interface under protection

• New PIM join Attribute to notify RPF neighbor (PLR) of downstream’s backup label X and MP’s RPF interface IP address, and router id. (This is needed only for node protection.)

IETF 76 5draft-lwei-pim-tmfrr-00

PIM Extension

• TMFRR Hello Option (Short)

– 8 bytes– L:0– N:Node Protection bit– M:MoFRR bit

IETF 76 draft-lwei-pim-tmfrr-00 6

0 3115 16

OptionType Length = 8

Reserved LMN

PIM Extension

• TMFRR Hello Option (Long)

– Include TMFRR label – Include router id– L:1– N:Node Protection bit– M:MoFRR bit

IETF 76 draft-lwei-pim-tmfrr-00 7

0 3115 16

OptionType Length

TMFRR Label (20bits) LMNReserved

Router ID in Encoded Unicast Address Format

PIM Extension

• Join Attribute– F: 0 Non-transitive– E: as specified by RFC5384– M: MoFRR bit– TMFRR label– Route-ID (of MP)– (Multiples of) Address of

Downstream Interfaces Under Protection

IETF 76 draft-lwei-pim-tmfrr-00 8

0 3115 16

Type Reserved

TMFRR Label (20bits) Reserved2

Router ID in Encoded Unicast Address Format

…

F E Length M

Address of Downstream Interface under protection

To PIM WG

• Please comment

IETF 76 9draft-lwei-pim-tmfrr-00