> Some people I know (yes really) are building a system that will have > several thousand little computers in some racks. Each of the > computers runs Linux and has a gigabit ethernet interface. It occurs > to me that it is unlikely that I can buy an ethernet switch with > thousands of ports, and even if I could, would I want a Linux system > to have 10,000 entries or more in its ARP table. > > Most of the traffic will be from one node to another, with > considerably less to the outside. Physical distance shouldn't be a > problem since everything's in the same room, maybe the same rack. > > What's the rule of thumb for number of hosts per switch, cascaded > switches vs. routers, and whatever else one needs to design a dense > network like this? TIA
Brocade's Virtual Cluster Switching (VCS) fabric on their VDX switches is a good solution for large, flat data center networks like this. It's based on TRILL, so no STP or tree structure are required. All ports are live, as is all inter-switch bandwidth. Cisco has a similar solution, as do other vendors. Thank you, Jerry -- Jerry J. Anderson, CCIE #5000 Member, Anderson Consulting, LLC 800 Ridgeview Ave, Broomfield, CO 80020-6618 Office: 650-523-2132 Mobile: 773-793-7717 www.linkedin.com/in/AndersonConsultingLLC