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 became active June 20th, 1997. 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 welcomes contributions.

The SIX offers GigE, 10GbE, 40GbE, and 100GbE port options. One-time port fees are detailed on our join page. The SIX does not charge recurring fees, but they are offered as a payment option.

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. We offer optional route servers.

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 GigE ports became available.
2001-12: PAIX / SIX interconnect turned up.
2006-09: First 10GbE 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 10GbE participants.
2009-07: Renumbered into IP address space assigned by ARIN.
2009-07: 10GbE port fee lowered from $10k to $5k NRC.
2011-08: Arista 7508 installed for 10GbE 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.
2014-07: Route servers introduced.
2014-08: 100GbE and 40GbE beta testing offered.
2014-09: 100GbE and 40GbE port fees introduced at $16k and $8k NRC respectively, plus optic.
2015-01: 10GbE port fee lowered from $5k to $3k NRC.
2015-01: First 100GbE participant.

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
2014-06: 270 Gbps
2014-09: 290 Gbps
2014-11: 310 Gbps
2014-12: 320 Gbps
2015-02: 360 Gbps
2015-05: 370 Gbps
2015-07: 380 Gbps
2015-08: 410 Gbps

Member Count:

Member Count