TRILL with Multicast draft-hares-trill-mutlicast.00.txt Susan Hares

Why Tuned multicast Normal Multicast plans for Rbridge –Broadcast all multicast packets to all RBridges for destinations with multicast group addresses –Doesn’t scale well

Draft Describes MAC FIB table changes 3 algorithms to generate multicast distribution Knobs/Features for improved performance –Path selection weight to give 1 path –Use of Link Bundles –Negotiating of reduced flooding between Rbridges –DataBase

3 Algorithms Described in Draft Multicast distribution tree rooted at MAC source address per Destination Group Address (S,G) state Flooding rooted at an Rbridge that detected –Group MAC address sending Reduced flooding to all Rbridges that Multicast for a VLAN or group of VLANs –Use the MCDS/MPR algorithms adapted to ISIS to reduce flooding

FIB tables for multicast Destination MAC Table Destination MAC RBridge List Group MAC-1 Rbridge-x, Rbridge-y, Rbridge-z Group MAC-2 Rbridge-w, Rbridge-z... Group MAC-n Rbridge-z, Rbridge-y Source MAC Table Source MAC Rbridge MAC-1 Rbridge-x MAC-10 Rbridge-z

Lookup table for Rbridge Source MAC Destination MAC Egress Encapsulation Rbridges Group MAC Unicast MAC MAC-1 Group-MAC 1 Rbridge-x, Group-MAC-3 [none] Rbridge-y, Rbridge-z MAC-10 Group-MAC-n Rbridge-z, MAC-5 Rbridge-y [none]

Encapsulation for Rbridge Forwarding of Encapsulations Unicast Encap MAC Next Rbridge MAC-5 Rbridge-a Multicast Encap MAC Next Rbridges Group-MAC-3 Rbridge-a, Rbridge-C

Multicast FIB generation takes Input: –Rbridge topology –(S-MAC, D-GMAC) state [snooped or GMRP learned] –(*,D-G-MAC) State –IP Mapping IP (S,G) to (S-MAC,D- GMAC) IP (*,G) to (*.D-GMAC) –Rbridge link path selection weights Output –D-GMAC to Rbridge mapping –S-MAC to Rbridge mapping –FIB for Rbridge encapsulation

Basic concept Extend ISIS along the lines of MOSPF –Multicast FIB (per VLAN, AFI/SAFI) –Multicast weights on links/paths (TE and non-TE) –Multicast tree growing algorithms –Extend hellos –TLV pairs (new group multicast TLV)

S,G Multicast Tree Calculation rooted at S MAC 1. Flooding Information via Link State 2. Sorting (S,G,Rbridge) into S-[G- sets,Rbridges-set] 3. Calculating a multicast forwarding tree based in the source for S-[G- Sets,Rbridge]

TLVs for Multicast from Rbridge TLV sent from originating Rbridge TLV1: Source MAC address Source MAC Address IDentifier Count of Unicast Source MAC Addresses Source MAC 1 [Flag Add/Delete, Encrypted/None] Source MAC 2 Source MAC n [count of Group MACs associated with Source set] [MAC Group Identifier - number] TLV2: Group MAC set Count of Multicast MAC addresses Group MAC Address-1 [6 bytes][ Flag byte -Add/Delete, Encrypt/None] Group MAC Address-2... Group MAC Address -n [count of Groups of Source MAC adddresses Associted with Group] [Source MAC Identifiers]

S,G Multicast Tree Calculation to all G-Group MACs 1. Flooding Information via Link State 2. Sorting the (Group-MAC-set,Rbridge> into Rbridge-(*,G)sets that share the same Group- MAC-Sets 3. Calculating a multicast forwarding tree from each Rbridge to the Rbridge-(*,G)sets 4. Updating the forwarding table with the results

Reduced Flooding Use reduced flooding techniques –Reduce packets sent multiple times The OSPF manet work has two drafts: – OSPF with Minimum Connected Dominating Sets (MCDS) calculated and optionally sent. (draft-chandra-ospf-manet-ext) –OSPF with MPR sets calculated and always sent (draft-ogier-manet-ospf-extension-04)

Multicast TLVs |Source MAC Group ID (4 octet) | | count of Unicast MAC addr (2 octet) | | Source MAC Address 1 (6 octet) | | MAC 1 Flag (Add/Delete, Encrypt/none (1 octet) | | Source MAC Address 2 (6 octets | | MAC 2 Flag (Add/Delte, Encrypt/none) (1 octet) | | | | count sets of Group MACs (2 octets) | Group set 1 Identifier (6 octest)

Group MAC address info |Group MAC Group ID (4 octet) | | count of Group MAC addr (2 octet) | | Group MAC Address 1 (6 octet) | | MAC 1 Flag (Add/Delete, Encrypt/none (1 octet) | | Group MAC Address 2 (6 octets | | MAC 2 Flag (Add/Delte, Encrypt/none) (1 octet) | | | | count sets of Source MACs (2 octets) | Group of Source MAC set 1 Id (6 octets) Group of Source MAC set N ID (6 octets>