SIX Logo


The Seattle Internet Exchange (SIX) was originally established in April 1997 as a private interconnection between two ISP's in Seattle's Westin building, whose traffic was traveling from Seattle to Texas and back just to cross from one side of the floor to the other. Starting in June 1997 other ISP's became interested in interconnecting, and the SIX was formed. Networks began to participate in the SIX due to the low/no cost involved, and it began to grow.

Faced with a growing number of participants and a rather ad hoc arrangement of hubs/switches and cable termination points, early members of the exchange petitioned the building for a neutral space. The building management obliged and allocated space for the SIX adjacent to the building's T1/T3 (and later fiber) meet-me rooms. This provided the SIX with a neutral, provider independent home.

The SIX donor model makes it so there is no fee for an organization's first GigE port, but multi-GigE and 10GE ports may involve a one-time port fee.

The SIX does not charge recurring fees.

There are no requirements of participants, other than they follow the rules of the exchange. There are no peering requirements, although peering with other members is encouraged and is basically the point of connecting to the exchange.

For information about joining the SIX, click here.

Port counts over time can be found here: csv png xls

Information on other exchange points can be found here.

Major Milestones:

1997-04: IXA and Wolfe form private interconnect.
1997-06: Hub added and Altopia connects. The exchange is born.
1997-11: Renumbered into Bill Manning / EP.NET IP address space.
1998-01: Petition letter given to Westin Building management requesting neutral space.
1998-05: First "national" network, AboveNet, joined the exchange.
1998-06: Replaced 10 megabit hub with a Cisco 1900 XL 10/100 switch.
1998-07: Moved out of IXA suite and into the current SIX space.
1999-02: Microsoft joined the SIX which acted as a considerable catalyst for growth.
2001-05: Incorporated as a non-profit.
2001-09: Cisco 4912G installed. First gigabit ports became available.
2001-12: PAIX / SIX interconnect turned up.
2006-09: First 10 gigabit participant.
2007-05: Cisco 6509 installed as the core switch.
2008-09: Received IRS section 501(c)(6) income tax exempt status.
2009-02: Activated VLAN specifically for multicast peering.
2009-07: Cisco Nexus 5020 installed for 10 gigabit participants.
2009-07: Renumbered into IP address space assigned by ARIN.
2009-07: 10GE port fee lowered from $10k to $5k NRC.
2011-08: Arista 7508 installed for 10 gigabit participants.
2011-09: Cisco Nexus 5020 retired.
2013-04: Began using AMS-IX's "arpsponge" software. Much appreciation to Steven Bakker, Arien Vijn and AMS-IX for sharing this brilliant technology.
2014-02: First MTU 9000 peering.

Aggregate Peak Traffic Milestones:

2007-07: 10 Gbps
2008-06: 20 Gbps
2009-01: 30 Gbps
2009-07: 40 Gbps
2010-02: 50 Gbps
2010-09: 60 Gbps
2010-12: 70 Gbps
2011-03: 80 Gbps
2011-06: 90 Gbps
2011-09: 100 Gbps
2012-03: 110 Gbps
2012-09: 120 Gbps
2012-10: 130 Gbps
2012-11: 150 Gbps
2013-02: 170 Gbps
2013-09: 190 Gbps
2013-10: 220 Gbps
2014-01: 240 Gbps
2014-02: 250 Gbps
2014-03: 260 Gbps