We are actually looking at going Layer 3 all the way to the top of rack and make each rack its own /24. This provides us flexibility when doing maintenance (spanning-tree). Also, troubleshooting during outages is much easier by using common tools like ping and trace routes. I want to make sure this is something other people are doing out there and want to know if anyone ran into any issues with this setup. Thanks, Raj Singh | Director Network Engineering _________________________________ Demand Media | eNom, Inc. Direct: 425.974.4679 15801 NE 24th St. Bellevue, WA 98008 Raj.Singh@DemandMedia.com -----Original Message----- From: Paul Stewart [mailto:pstewart@nexicomgroup.net] Sent: Thursday, November 12, 2009 11:53 AM To: Raj Singh; nanog@nanog.org Subject: RE: Layer 2 vs. Layer 3 to TOR We are heading towards that type of deployment beginning next year with Juniper EX4200 switches in a redundant configuration. This will be pure Layer2 in nature on the switches and they will "uplink" to Juniper M10i's for layer3... the power savings, space savings etc over traditional Cisco 6500 chassis (plus all the cabling between cabinets which is in our case a nightmare) made this a pretty easy choice... and price too..;) Somewhere on Juniper's website in the product info section they have deployment whitepapers on this kind of stuff if that's of interest.... Hope this helps.. Paul -----Original Message----- From: Raj Singh [mailto:raj.singh@demandmedia.com] Sent: November-12-09 2:49 PM To: 'nanog@nanog.org' Subject: Layer 2 vs. Layer 3 to TOR Guys, I am wondering how many of you are doing layer 3 to top of rack switches and what the pros and cons are. Also, if you are doing layer 3 to top of rack do you guys have any links to published white papers on it? Thanks, Raj Singh ---------------------------------------------------------------------------- "The information transmitted is intended only for the person or entity to which it is addressed and contains confidential and/or privileged material. If you received this in error, please contact the sender immediately and then destroy this transmission, including all attachments, without copying, distributing or disclosing same. Thank you."