TRILL Working Group

1
TRILL Working Group

• From draft 03 to draft 04
• Dinesh Dutt, Cisco
• Silvano Gai, Nuova
• Radia Perlman, Sun

2
Agenda

• Bridge vs RBridge Reuse/Specify
• SVL vs IVL
• ST compatibility to which extent?
• Other 802.1 protocols compatibility?
• IS-IS TLV formats

3
Bridge vs RBridge Reuse/Specify

• Data Plane
• What is leveraged from .1Q and what is new
• Learning
• Do we support IVL and SVL?
• Control Plane
• What versions of STP will we support
• What about non-STP protocols such as GARP, GVRP
  etc.

4
Data Plane (1)
LLC
LLC
Ingress Rules
Ingress Rules
Port State
Port State
Forwarding Process
EISS
EISS
Filtering Database
Bridge Port TX/RX
Bridge Port TX/RX
ISS
ISS
802.n
802.n
LAN
LAN
Reuse
Specify
Not Sure
5
Data Plane (2)

• From IEEE 802.1Q, TRILL uses
• Bridge port transmit and receive
• EISS
• It includes port-and-protocol-based VLAN
  classification
• Port States
• no new states are defined
• Ingress Rule / Egress Rule

6
EISS (Enhanced Internal Sublayer Service)

• API that provides a normalized frame (independent
  of tagging) to the forwarding process
• Shall we assume that the RBridges interface is
  the same ?
• Assumes that TRILL header encap/decap is part of
  forwarding process

EM_UNITDATA.indication ( destination_address, sour
ce_address, mac_service_data_unit, priority, vlan_
identifier, frame_check_sequence, canonical_format
_indicator, rif_information (optional) )
EM_UNITDATA.request ( destination_address, source_
address, mac_service_data_unit, priority, vlan_ide
ntifier, frame_check_sequence, canonical_format_in
dicator, rif_information (optional) )
7
Data Plane (3)

• TRILL specifies
• Forwarding Process
• Includes Encap/Decap of shim header
• Filtering database extension to
• Support TRILL encap decision
• Identify Egress RBridge
• Identify distribution tree for multi-destination
  frames
• Identify encapsulation and address to reach Next
  Hop Rbridge

8
Learning (1)
IS-IS
LLC
LLC
Ingress Rules
Ingress Rules
EISS
EISS
Filtering Database
Bridge Port TX/RX
Bridge Port TX/RX
ISS
ISS
802.n
802.n
LAN
LAN
Reuse
Specify
Not Sure
9
Learning (2)

• IEEE 802.1Q distinguishes between
• VID VLAN ID
• FID Filtering ID
• This allows
• IVL (Independent VLAN learning) one VID equal
  one FID
• SVL (Shared VLAN learning) multiple VIDs map to
  one FID
• TRILL assumes the IVL model
• It announces through IS-IS MAC Address, VID
  pairs learnt locally
• Does TRILL care about IVL and SVL issues or not ?
• SVL has not been fully investigated
• Should TRILL additionally announce FID to VID
  association ?

10
Control Plane (1)
IS-IS
ST (per port)
LLC
LLC
Ingress Rules
Ingress Rules
Port State
Port State


EISS
EISS
Filtering Database
Bridge Port TX/RX
Bridge Port TX/RX
ISS
ISS
802.n
802.n
LAN
LAN
Reuse
Specify
Not Sure
11
Control Plane (2)

• TRILL adds IS-IS
• Need to formally specify IS-IS TLVs
• The port state is controlled by
• Designated RBridge election
• Spanning Tree
• We need a ST per port per VLAN
• Different from classical ST that is common to all
  ports
• We need to add an algorithm to combine the ST
  state and the DR state into a port State

12
Spanning Trees (1)

• Which styles does TRILL support
• STP YES
• RSTP YES
• MSTP - ???

Since the original Spanning Tree Protocol (STP)
has been removed from the 2004 revision of IEEE
Std 802.1D, an implementation of RSTP is required
for any claim of conformance for an
implementation of IEEE Std 802.1Q-2003 that
refers to the current revision of IEEE Std 802.1D
unless that implementation includes the Multiple
Spanning Tree Protocol (MSTP) specified in IEEE
Std 802.1Q-2003. MSTP is based on RSTP, extended
to provide support for multiple spanning trees.
13
Other Restrictions ofthe first version of TRILL

• No support for
• GARP and its derivatives such as GVRP, GMRP
• RIF (Routing Information)
• CFI different from 0

14
ARP/ND

• Is ARP/ND support mandatory for an RBridge ?
• One suggestion
• TRILL MUST provide mechanisms to carry this
  information in IS-IS, if known
• To avoid interoperability issues
• TRILL SHOULD NOT specify how to learn it
• TRILL SHOULD NOT specify proxy ARP/ND behavior
• TRILL implementation may decide to optimize
  ARP/ND
• ARP/ND optimization and such can be called out in
  a separate draft

15
IS-IS TLV Formats

• draft-ward-l2isis-01.txt has expired
• Need to restart and finalize TLV formats