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Rough Outline for a Intra-Portal Protocol Version 01. Stephen Haddock July 17, 2012. LACP in a Nutshell. Each Port on a System advertises: A System ID The same System ID value is used for all Ports on a System. A Key
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Rough Outline for a Intra-Portal ProtocolVersion 01 Stephen Haddock July 17, 2012
LACP in a Nutshell • Each Port on a System advertises: • A System ID • The same System ID value is used for all Ports on a System. • A Key • The Key is an indication of aggregation capability. Ports that can be aggregated advertise the same Key value. • A Port ID • The Port ID is included to handle some special cases. It is not important for a high level understanding of basic LACP concepts. • LACP Selection Logic will form an aggregation between any ports that: • Advertise the same System ID and the same Key (called the Actor_System and Actor_Key), and • Receive advertisements containing the same System ID and the same Key (called the Partner_System and Partner_Key)
Two Systems without Distributed Aggregation System A System B Port Port Port Port Port Port Port Port Port Port Each Port on System A advertises: Actor_System = A Actor_Key = Ax Where Ax may be the same value on some or all of the ports, or may be a different value on different ports. Each Port on System B advertises: Actor_System = B Actor_Key = Bx Where Bx may be the same value on some or all of the ports, or may be a different value on different ports.
Two Systems with Distributed Aggregation System A System B Port Port Port Port Port Port Port Port (possible) Network Link Intra-Portal Link (could be virtual) Network Link Network Link Gateway Link (virtual) Gateway Link (virtual) Emulated System C Port Port Port Port Port Port Each Network Port on System A advertises: Actor_System = A Actor_Key = Ax Each Network Port on System B advertises: Actor_System = B Actor_Key = Bx Each (non Gateway) Port on System C advertises: Actor_System = C Actor_Key = Cn Where Cn is the same value on all of the ports.
Intra-Portal Protocol Creating and Maintaining a Distributed Aggregation requires: • State machines in System A and System B (the “real” systems) to control the transitions between the state without distributed aggregation and the state with distributed aggregation. • A protocol that • Determines the System ID and Key values for the Emulated System C. • Coordinates the Selection Logic for the Emulated System C. • Coordinates the distributed aggregation state machines in each of the “real” systems.
Configuration versus Discovery • LACP designed to allow minimal configuration and maximal discovery: • A default configuration is all ports advertise the same key value. • LACP will then discover all groups of ports connecting the same pair of systems and automatically aggregate them. • The Intra-Portal Protocol could conceivably follow the same philosophy: • Advertise ability to do distributed aggregation on all ports. • Form an Intra-Portal Link to any connected system that is also capable of distributed aggregation, and create an emulate system between them. • Use LACP (possibly with enhancements) to discover links that could form a distributed aggregation and “move” those ports to the emulated system. • This is quite ambitious!
A less ambitious starting point • Configure the port(s) that are expected to form Intra-Portal Links. • Use protocol advertisements on those ports to verify that the other system also expects these to form Intra-Portal Links, and to agree on Emulated System parameters (System ID, Key value, Port IDs). • Configure which port(s) are expected to be “moved” to the Emulated System. • Once the Intra-Portal Link is active and Emulated System parameters agreed, use LACP to advertise the Emulated System parameters these ports. • Intra-Portal Protocol coordinates the Selection Logic of the Emulated System to form the distributed aggregation.
Rough Distributed Aggregation State Machine Begin IPPort Operational & IPProtocol Advertisements received SINGLE BETROTHED • LACP advertises “real” system parameters on all ports. • Send Intra-Portal Protocol advertisements (candidate Emulated System parameters) on potential Intra-Portal Port. • LACP advertises “real” system parameters on all ports. • Send Intra-Portal Protocol advertisements on Intra-Portal Port. All communication with spouse lost All communication with spouse lost All communication with spouse lost Not in sync In sync (Emulated System parameters agreed) ESTRANGED MARRIED IPPort Operational & IPProtocol Advertisements received • LACP advertises Emulated System parameters on Emulated System ports. • Send Intra-Portal Protocol advertisements on Intra-Portal Port and alternate paths. • Maintain Distributed Aggregation • LACP advertises Emulated System parameters on Emulated System ports. • Send Intra-Portal Protocol advertisements on Intra-Portal Port (and alternate paths?). • Create Distributed Aggregation. IPPort not Operational but communication through other paths possible
Intra-Portal Protocol Advertisements • Ethertype • Maybe use Slow Protocols Ethertype with new sub-type • Maybe use new Ethertype (without chatter limits) • Modeled after LACP advertisements • Contains Actor parameters • Actor_System, Actor_Emulated_System, Actor_Distributed_Key, Actor_State • Contains copies of parameters received from Spouse • Spouse_System, Spouse_Emulated_System, Spouse_Distributed_Key, State • In sync when the Spouse_* parameters in received advertisements match the Actor_* parameters in transmitted advertisements. • The agreed Emulated_System identifier is the numerically lower of that proposed by the Actor or the Spouse. • The agreed Distributed_Key is the value associated with the agreed Emulated_System identifier. • May contain other TLVs in some or all advertisements for coordinating gateway selection, link selection, etc.