TRILL with Multicast

1
TRILL with Multicast

• draft-hares-trill-mutlicast.00.txt
• Susan Hares

2
Why Tuned multicast

• Normal Multicast plans for Rbridge
• Broadcast all multicast packets to all RBridges
  for destinations with multicast group addresses
• Doesnt scale well

3
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

4
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

5
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

6
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

7
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

8
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

9
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)

10
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

11
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

12
S,G Multicast Tree Calculation to all G-Group MACs

• 1. Flooding Information via Link State
• 2. Sorting the (Group-MAC-set,Rbridgegt 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

13
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)

14
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) --------------------------
--------------------------
.................................
----------------------------------
--------------------------------------------------
----------
15
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
octetsgt --------------------------------
--------------------