Tutorial: Bringing Experimenters to GENI with the Transit Portal

Vytautas Valancius, Hyojoon Kim, Nick FeamsterGeorgia Tech

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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

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Networks Use BGP to Interconnect

Route Advertisement

Autonomous Systems

Session

Traffic

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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 overtraffic

• Need “BGP”– Setting up individual

sessions is cumbersome– …particularly for transient

experiments

ISP 1 ISP 2

BGP Sessions

GENI

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• 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

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Route Control with Transit Portal

Experiment Facility

Experiment Facility

Experiment 1

Experiment 2

Internet

Internet

ISP1ISP1

ISP2ISP2

Virtual Router

B

Virtual Router

B

Virtual Router

A

Virtual Router

A

Transit PortalTransit Portal

Routes

Packets

Full Internet route control to hosted cloud services!

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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

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Transit PortalTransit Portal

Virtual BGP

Router

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 1ISP 1 ISP 2ISP 2

Interactive Cloud Service

BGPSessions

Traffic

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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)

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Demonstration of Transit Portal

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Demonstration Setup

TransitPortalTransitPortal

GT(AS 2637)

GT(AS 2637)

VPNTunneling Virtual

RouterVirtualRouter

: BGP connectivity

Client network:168.62.21.0/24

Private AS

65002

Private AS

65002

Public AS

47065

Public AS

47065

Looking-glass Server

Looking-glass Server

Traceroute

route-server.ip.att.net

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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

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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

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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)

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Sample OpenVPN Configuration

# OpenVPN config file

client

dev tunproto tcpremote 143.215.254.26 6000nobind

persist-keypersist-tun

# certification partca ca.crtcert nick.crtkey nick.key

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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)

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Example Quagga Configuration

!hostname kendallpassword XXXXX!router bgp 65003 bgp router-id 168.62.21.15 network 168.62.20.0/24 neighbor 168.62.21.1 remote-as 2637!access-list vty permit 127.0.0.1/32!line vty access-class vty!

hostname kendallpassword crazymuxaccess-list vty permit 127.0.0.1/32!

bgpd configuration zebra configuration

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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

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Experiments Using Transit Portal

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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

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ISP1

ISP1

ISP2

ISP2

ISP3

ISP3

ISP4

ISP4

Transit PortalTransit Portal

Transit PortalTransit Portal

Asia North America

Anycast Routes

Name ServiceName Service

IP Anycast

• Host service at multiple locations (e.g., on ProtoGENI)• Direct traffic to one instance of the service or another using anycast

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Using TP in Courses

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• 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

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Example Problem Set

• Set up virtual network with– Intradomain routing– Hosted services– Rate limiting

• Connect to Internet with Transit Portal

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More Example Experiments

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• 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

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ISP1

ISP1

ISP2

ISP2

ISP3

ISP3

ISP4

ISP4

Transit PortalTransit Portal

Transit PortalTransit Portal

Asia North America

Tunneled SessionsTunneled Sessions

Active GameService

InternetInternet

Service Migration

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Experiment 3: Flexible Peering

Hosted service can quickly provision services in the cloud when demand fluctuates.

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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

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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 http://valas.gtnoise.net/tp

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Transit Portal in the News

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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

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Extra Slides

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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

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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

ISP1ISP1 ISP2ISP2

BGP Router

BGP Router

Updates

Client BGP

Router

Client BGP

Router

Client BGP

Router

Client BGP

Router

Packets

37Bulk Transfer

Routing ProcessRouting 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

ISP1ISP1 ISP2ISP2

Virtual RouterVirtual Router

Virtual RouterVirtual Router

Routing

Table 1

Routing

Table 1

Routing

Table 2

Routing

Table 2

Interactive Service

38Bulk Transfer

Routing ProcessRouting 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

ISP1ISP1 ISP2ISP2

Virtual RouterVirtual Router

Virtual RouterVirtual Router

Routing

Table 1

Routing

Table 1

Routing

Table 2

Routing

Table 2

Interactive Service

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Forwarding TableForwarding 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

ISP1ISP1 ISP2ISP2

Virtual BGP

Router

Virtual BGP

Router

Virtual BGP

Router

Virtual BGP

Router

Forwarding Table

1

Forwarding Table

1

Forwardng Table 2Forwardng Table 2

Bulk TransferInteractive Service