TRILL Working Group
From draft 03 to draft 04
Dinesh Dutt, Cisco
Silvano Gai, Nuova
Radia Perlman, Sun
March 2007
68th IETF - Prague
1
Agenda
• Bridge vs RBridge: Reuse/Specify
– SVL vs IVL
– ST compatibility: to which extent?
– Other 802.1 protocols compatibility?
• IS-IS TLV formats
March 2007
From draft 03 to draft 04
2
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.
March 2007
From draft 03 to draft 04
3
Data Plane (1)
LLC
LLC
Ingress
Rules
Port
State
Bridge Port TX/RX
Forwarding
Process
Filtering
Database
ISS
802.n
March 2007
Bridge Port TX/RX
ISS
802.n
LAN
Reuse
Ingress
Rules
Port
State
LAN
Specify
From draft 03 to draft 04
Not Sure
4
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
March 2007
From draft 03 to draft 04
5
EISS (Enhanced Internal Sublayer
Service)
• API that provides a normalized frame (independent of
tagging) to the forwarding process:
– Shall we assume that the RBridge’s interface is the same ?
– Assumes that TRILL header encap/decap is part of forwarding
process
EM_UNITDATA.indication (
destination_address,
source_address,
mac_service_data_unit,
priority,
vlan_identifier,
frame_check_sequence,
canonical_format_indicator,
rif_information (optional)
)
March 2007
EM_UNITDATA.request (
destination_address,
source_address,
mac_service_data_unit,
priority,
vlan_identifier,
frame_check_sequence,
canonical_format_indicator,
rif_information (optional)
)
From draft 03 to draft 04
6
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
March 2007
From draft 03 to draft 04
7
Learning (1)
IS-IS
LLC
Ingress
Rules
Bridge Port TX/RX
Ingress
Rules
Filtering
Database
ISS
802.n
March 2007
Bridge Port TX/RX
ISS
802.n
LAN
Reuse
LLC
LAN
Specify
From draft 03 to draft 04
Not Sure
8
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 ?
March 2007
From draft 03 to draft 04
9
Control Plane (1)
LLC
IS-IS
ST (per port)
Ingress
Rules
Port
State
Ingress
Rules
Port
State
Bridge Port TX/RX
+
+
Filtering
Database
ISS
802.n
March 2007
Bridge Port TX/RX
ISS
802.n
LAN
Reuse
LLC
LAN
Specify
From draft 03 to draft 04
Not Sure
10
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
March 2007
From draft 03 to draft 04
11
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.
March 2007
From draft 03 to draft 04
12
Other Restrictions of
the first version of TRILL
• No support for:
– GARP and its derivatives such as GVRP,
GMRP
– RIF (Routing Information)
– CFI different from 0
March 2007
From draft 03 to draft 04
13
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
March 2007
From draft 03 to draft 04
14
IS-IS TLV Formats
• draft-ward-l2isis-01.txt has expired
• Need to restart and finalize TLV formats
March 2007
From draft 03 to draft 04
15