* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Chervet Benjamin
Survey
Document related concepts
Power over Ethernet wikipedia , lookup
Point-to-Point Protocol over Ethernet wikipedia , lookup
Distributed firewall wikipedia , lookup
Piggybacking (Internet access) wikipedia , lookup
IEEE 802.1aq wikipedia , lookup
Wake-on-LAN wikipedia , lookup
Recursive InterNetwork Architecture (RINA) wikipedia , lookup
Computer network wikipedia , lookup
Zero-configuration networking wikipedia , lookup
List of wireless community networks by region wikipedia , lookup
Cracking of wireless networks wikipedia , lookup
Network tap wikipedia , lookup
Airborne Networking wikipedia , lookup
Transcript
Floodless in SEATTLE : A Scalable Ethernet ArchiTecTure for Large Enterprises. Changhoon Kim, Matthew Caesar and Jenifer Rexford. Princeton University 2009, 3rd March Presented by Chervet Benjamin Animation on page 9, 14, 15 and 16 come from Changhoon Kim’s presentation. 1 Motivation Networks are getting larger 2 Up to 25 000 hosts and 1 000 switchs for large enterprises Networks. Larger and larger datacenter at Google, Yahoo or Microsoft for the largest ones. Everyone in a University has access to the Internet. Motivation (2) Networks are getting larger Hard to keep efficient, recquires networks administrators and operators. More money is spent on maintenance than improving the Network with new materials. Need to find out where the problems is and how to solve it. 3 Outline Find where the problem is : Current Networks Solve the problem : Seattle architecture Objectives Solutions offered Evaluate the solutions : Ethernet Network Hybrid (Ethernet/IP) Network Comparison Ethernet/IP Simulation results Experimental results Conclusion 4 Benefits Lessons Learned Current Networks Ethernet Network -Heavily rely on broadcast to know where a host is (ARP, DHCP) - large use of bandwidth, - privacy concerns + learn automatically the address, + ensure mobility of a machine -Flat addressing : Switch maintains a table associating all the Mac Address of the Network with its output ports. -can lead to very large table -Build a spanning tree + No loops in the Network - links unused - uneven loads 5 Actual Networks Ethernet Network 6 Actual Networks Hybrid IP/Ethernet Networks LAN -The broadcast stay in a subnet. + No flood on the entire Network. - Manual configuration needed. - No mobility possible. LAN IP Network LAN 7 Machine sharing the same subnets. The subnet are interconnect by IP Networks. -Routing done though OSPF + Efficient use of links + No loops Actual Networks Hybrid IP/Ethernet Network 8 Comparaisons Architectures Features Ease of configuration Optimality in addressing Host mobility Path efficiency Load distribution Convergence speed Tolerance to loop 9 Ethernet Bridging IP Routing SEATTLE Comparaisons SEATTLE : Get the best of Ethernet and IP. Configuration free (like Ethernet) and Scalable (as IP). 10 Seattle architecture Objectives Avoid flooding Limits broadcasting Directory service Keep forwarding tables small 11 Send a message only to the receiver Never broadcast unicast traffic Host location should be kept only where it is needed Distribution of the data. Seattle architecture Objectives (2) Path efficient. Backward compatible 12 Need a routing protocol Switch can learn the topology Compatible with IP and Ethernet Network Does not modify end-hosts view Seattle architecture Solution offered : Network layer one hop DHT All the Switch implement a hash function F, associating <key, value> pair. - For every key F returns the same value. - F returns one of the switch from a key. - Each Switch must know about all the other living switch. Cache system is used :the switch cache some frequently used information Smart cache update implemented : retrieves the information by surveying the traffic. 13 How does it works ? x Deliver to x Host discovery or registration C y Traffic to x A Hash (F(x) = B) Tunnel to egress node, A Entire enterprise (A large single IP subnet) Switches End-hosts Control flow Data flow 14 Optimized forwarding directly from D to A Tunnel to relay switch, B D LS core Notifying <x, A> to D B Store <x, A> at B Hash (F(x) = B) E Response to host mobility Old Dst x < x, G > < x, A > when shortest-path forwarding is used A D < x, A > < x, G > Relay (for x) New Dst G < x, G > 15 B < x, A > < x, G > y Src SEATTLE Architecture Handling ARP requests 4. Broadcast ARP req for a Owner of (IPa ,maca) sb a 1. Host discovery sa 2. Hashing 6. Unicast ARP req to ra F(IPa) = ra 5. Hashing F(IPa) = ra 7. Unicast ARP reply (IPa , maca , sa) to ingress Switch End-host Control msgs ARP msgs 16 b ra 3. Storing (IPa ,maca , sa) Evaluation of the solutions We want to know if the new solutions performs better than current networks ? Simulation using a packet simulator 4 different topologies 17 Campus network (517 routers and switches) AP-small (87 routers) AP-large (315 routers) DC (Data center network) Stretch: Path Optimality Stretch = Current path length / Shortest path length 18 Control messages 19 Size of the tables 20 Experimentation on Emulab Emulab: similar to planetLab: set of PC around the world. Useful to test real world networks with some practical values for latency and bandwidth In this experimentation: 10 PC Free BSD Nodes 21 Number of messages exchanged 22 Conclusions: Benefits : Reduce the flow of data exchanged by order of magnitude Fast and efficient reaction to changes Reliability and capacity grows with the size of Network Less man-made configuration needed Plug and Playable Networking ensuring efficiency and scalability. 23 Conclusions Lessons learned A new protocols has been created by combining different technologies from different background. 24 DHT Based routing used first in P2P technologies. Link state routing Caching