1. Terena Netwoking Conference 2009 Network core design for business continuity architectures Martí Griera - Juanan Martínez Servei d’Informàtica Universitat Autònoma de Barcelona

2. Terena Netwoking Conference 2009 Agenda Context The Campus Network today Tomorrow’s network The manufacturer approach Our vision Considerations Conclusions

3. Terena Netwoking Conference 2009 Context Current (future?) business trends: From network availability to business continuity Do it for less Do it the green way Classic operational principles: Fit to standards Keep it simple

4. Terena Netwoking Conference 2009 In short... Could you implement a business class network topology which easily accommodates distributed services in a cost effective way, not being tied to any specific manufacturer?

5. Terena Netwoking Conference 2009 The Campus Network today Simple and fast (for today’s speed needs!) Easy to troubleshoot Centralized intelligence The highly redundant core guarantees service availability (or not?) Double internet connection: different routers but same location........... Interne t Interne t

6. Terena Netwoking Conference 2009 Our example Core L3 Routing technology (implemented in a Cisco 6513, second router Standby) Buildings with 1/2 connections to the main core VLAN distribution for specific activities (Wireless, ToIP) Main servers connected through a firewall blade to the same equipment Buildings Switching topology with multivendor equipment (3Com, Nortel, HP) Two levels: switching-core and user Internet connection Cisco 7200 (2) connected to the routing core Transparent firewalling

7. Terena Netwoking Conference 2009 Problems and desiderata  Core failure means total disaster (and it happens!)  Redundant links... but converging to a single point  Double internet connection, but also in the same physical location  Easy to operate and troubleshoot  Distributed approach  Standards based  Please... No complexity! It increases failure probability while enlarging troubleshooting time (and is prone to human mistake!)

8. Terena Netwoking Conference 2009 Building tomorrow’s network: The manufacturer approach VSS VRRP or virtual routing solutions Distributed proprietary routing solutions with proprietary interconnecting protocols In general, these solutions cost around 150- 200K€ for a Campus Core. As an additional consideration, you get tied to a specific manufacturer.

9. Terena Netwoking Conference 2009 Is there an alternative? Reliable switching core Simple protocols (fast STP) Physically distributed core by design Distributed routing layer Simple routing among buildings Direct connection between buildings can provide additional redundancy Distributed services Service accommodates easily By nature (DNS/DHCP) By application mechanisms By specific appliances

10. Terena Netwoking Conference 2009 Our (future) picture Switching Core (1G/10G) Switching Core (1G/10G) Internet Main datacenter (SI) Secondary Datacenter (Under Construction) Servers Server equipment

11. Terena Netwoking Conference 2009 Roadmap In our case, both for economic and risk-management considerations we have made a progressive approach to this topology. We suggest: Decide which will be the 2nd location Provide network equipment for this building (if not present) Segregate a building with an available subnet (can be a phantom/test building) Accommodate a testbed service Distribute DNS and DHCP services Segregate the buildings Distribute critical services Although our model has been designed for a Campus network we think it can be extended (probably with some minor modifications) to other environments

12. Terena Netwoking Conference 2009 Considerations Migration from a concentrated routing scheme to this distributed-routing switched-core network is simple Seamless migration procedure (evolution, not disruption) Routing moved to building-base Redundancy achieved through multiple paths with well- known (and proved) L2 protocols Easy accommodation of distributed datacenter for critical services Critical network services (DNS, DHCP) accommodates seamlessly to this topology Network operation requires no additional complexity Possibility to integrate different manufacturers (or at least, have real competency when choosing) Substantial cost reduction

13. Terena Netwoking Conference 2009 Conclussions Business continuity architectures can be achieved with classic protocols We believe strongly in standards and simple topologies as the best way to keep the network up and running smoothly With these ideas in mind, the combination of a fast switching core and a distributed simple routing creates a reliable framework for service-continuity Although it’s critical for us, if there are neither economic nor human-knowledge constraints, proprietary solutions can provide valid solutions which even can provide additional (also proprietary) features

14. Terena Netwoking Conference 2009 Questions & Comments