Tutorial: Bringing Experimenters to GENI with the Transit Portal Vytautas Valancius, Hyojoon Kim, Nick Feamster Georgia Tech

2 Agenda Motivation: Custom routing for each experiment Demonstration How you can connect to Transit Portal Experiment Ideas –Anycast –Service Migration –Flexible Peering Using Transit Portal in Education –Example problem set Summary and Breakout Ideas

3 Networks Use BGP to Interconnect Route Advertisement Autonomous Systems Session Traffic

4 Virtual Networks Need BGP Too Strawman –Default routes –Public IP address Problems –Experiments may need to see all upstream routes –Experiments may need more control over traffic Need “BGP” –Setting up individual sessions is cumbersome –…particularly for transient experiments ISP 1 ISP 2 BGP Sessions GENI

5 Obtain connectivity to upstream ISPs –Physical connectivity –Contracts and routing sessions Obtain the Internet numbered resources from authorities Expensive and time-consuming! Route Control Without Transit Portal

6 Route Control with Transit Portal Experiment Facility Experiment 1 Experiment 2 Internet ISP1 ISP2 Virtual Router B Virtual Router A Transit Portal Routes Packets Full Internet route control to hosted cloud services!

7 Connecting to the Transit Portal Separate Internet router for each service –Virtual or physical routers Links between service router and TP –Each link emulates connection to upstream ISP Routing sessions to upstream ISPs –TP exposes standard BGP route control interface

8 Transit Portal Virtual BGP Router Basic Internet Routing with TP Experiment with two upstream ISPs Experiment can re- route traffic over one ISP or the other, independently of other experiments ISP 1 ISP 2 Interactive Cloud Service BGP Sessions Traffic

9 Current TP Deployment Server with custom routing software –4GB RAM, 2x2.66GHz Xeon cores Three active sites with upstream ISPs –Atlanta, Madison, and Princeton A number of active experiments –BGP poisoning (University of Washington) –IP Anycast (Princeton University) –Advanced Networking class (Georgia Tech)

10 Demonstration of Transit Portal

11 Demonstration Setup Transit Portal Transit Portal GT (AS 2637) GT (AS 2637) VPN Tunneling Virtual Router Virtual Router : BGP connectivity Client network: /24 Private AS Private AS Public AS Public AS Looking- glass Server Looking- glass Server Traceroute route-server.ip.att.net

12 1.Pick a device which will be the virtual router (Linux) 2.Request for needed resources & provide information  For tunneling: CA certificate, client certificate & key  Get prefixes that the client will announce 3.Make tunneling connection with Transit Portal 4.Set up BGP daemon in virtual router (e.g. Quagga) 5.Make proper changes to routing table if necessary 6.Check BGP announcements & connectivity (BGP table)... and you are good to go! How You Can Connect to Transit Portal

13 Steps for Connecting to Transit Portal Setting up virtual machines Tunneling to the TP: Installing OpenVPN Getting routes: Setting up BGP Forwarding traffic: Setting up the data plane Testing connectivity: Traceroute

14 Tunneling to the Transit Portal Install OpenVPN Client Set up OpenVPN Connectivity (currently manual) –Get key pair from Transit Portal operator (Valas Valancius) –Determine IP address of tunnel endpoint –Notify operator of tunnel endpoint IP address Test connectivity (e.g., ping TP tunnel endpoint)

15 Sample OpenVPN Configuration # OpenVPN config file client dev tun proto tcp remote nobind persist-key persist-tun # certification part ca ca.crt cert nick.crt key nick.key

16 Discovering Internet Routes Install Quagga software router Download configuration template from GENI wiki Modify template with tunnel endpoint IP addresses Run bgpd and zebrad Check Linux kernel routing tables for routes Advertising routes: Need IP prefix (we have some)

17 Example Quagga Configuration ! hostname kendall password XXXXX ! router bgp bgp router-id network /24 neighbor remote-as 2637 ! access-list vty permit /32 ! line vty access-class vty ! hostname kendall password crazymux access-list vty permit /32 ! bgpd configuration zebra configuration

18 Setting Up Traffic Forwarding Give some machine in your testbed an address within the IP prefix Configure “gateway” to route traffic for that IP address to the appropriate location

19 Experiments Using Transit Portal

20 Experiment 1: IP Anycast Internet services require fast name resolution IP anycast for name resolution –DNS servers with the same IP address –IP address announced to ISPs in multiple locations –Internet routing converges to the closest server Available only to large organizations

21 ISP 1 ISP 2 ISP 3 ISP 4 Transit Portal Asia North America Anycast Routes Name Service IP Anycast Host service at multiple locations (e.g., on ProtoGENI) Direct traffic to one instance of the service or another using anycast

22 Using TP in Courses

23 Used in “Next-Generation Internet” Course at Georgia Tech in Spring 2010 Students set up virtual networks and connect directly to TP via OpenVPN (similar to demonstration) –Live feed of BGP routes –Routable IP addresses for in class topology inference and performance measurements Using TP in Your Courses

24 Example Problem Set Set up virtual network with –Intradomain routing –Hosted services –Rate limiting Connect to Internet with Transit Portal

25 More Example Experiments

26 Internet services in geographically diverse data centers Operators migrate Internet user’s connections Two conventional methods: –DNS name re-mapping Slow –Virtual machine migration with local re-routing Requires globally routed network Experiment 2: Service Migration

27 ISP 1 ISP 2 ISP 3 ISP 4 Transit Portal AsiaNorth America Tunneled Sessions Active Game Service Internet Service Migration

28 Experiment 3: Flexible Peering Hosted service can quickly provision services in the cloud when demand fluctuates.

29 Ongoing Developments More deployment sites –Your help is desperately needed Integrating TP with network research testbeds (e.g., GENI, CoreLab) Faster forwarding (NetFPGA, OpenFlow) Lightweight interface to route control

30 Conclusion Limited routing control for hosted services Transit Portal gives wide-area route control –Advanced applications with many TPs Open-source implementation –Scales to hundreds of client sessions The deployment is real –Can be used today for research and education –More information

31

32 Transit Portal in the News

33 Breakout Session Agenda Q & A Demonstration Redux Brainstorming Experiments –MeasuRouting: Routing-Assisted Traffic Monitoring –Pathlet Routing and Adaptive Multipath Algorithms –Aster*x: Load-Balancing Web Traffic over Wide-Area Networks –Migrating Enterprises to Cloud-based Architectures

34 Extra Slides

35 Scaling the Transit Portal Scale to dozens of sessions to ISPs and hundreds of sessions to hosted services At the same time: –Present each client with sessions that have an appearance of direct connectivity to an ISP –Prevented clients from abusing Internet routing protocols

36 Conventional BGP Routing Conventional BGP router: –Receives routing updates from peers –Propagates routing update about one path only –Selects one path to forward packets Scalable but not transparent or flexible ISP1 ISP2 BGP Router Updates Client BGP Router Packets

37 Bulk Transfer Routing Process Scaling TP Memory Use Store and propagate all BGP routes from ISPs –Separate routing tables Reduce memory consumption –Single routing process - shared data structures –Reduce memory use from 90MB/ISP to 60MB/ISP ISP1 ISP2 Virtual Router Routing Table 1 Routing Table 2 Interactive Service

38 Bulk Transfer Routing Process Scaling TP CPU Use Hundreds of routing sessions to clients –High CPU load Schedule and send routing updates in bundles –Reduces CPU from 18% to 6% for 500 client sessions ISP1 ISP2 Virtual Router Routing Table 1 Routing Table 2 Interactive Service

39 Forwarding Table Scaling Forwarding Memory Connecting clients –Tunneling and VLANs Curbing memory usage –Separate virtual routing tables with default to upstream –50MB/ISP -> ~0.1MB/ISP memory use in forwarding table ISP1 ISP2 Virtual BGP Router Forwardin g Table 1 Forwardng Table 2 Bulk Transfer Interactive Service