Designing Cisco Network Service Architectures - Free Books

Server Farm ModuleIn each data center, there are many servers organized into rows. Each server row is connects toa pair of Cisco Catalyst 6509 Series access switches placed at the end of the row. Eight serverrows connect to a pair of Layer 3 Cisco Catalyst 6509 Series aggregation switches using 4Gbps EtherChannel. Although a smaller chassis might have been used for the aggregationswitches, this approach keeps the equipment model inventory simple and allows space forNAM blades and service modules.There are currently two pairs of aggregation switches (two aggregation modules of 8 rowseach) connecting to the core server switches by 4 Gbps EtherChannel.The corporate mainframes also connect to switches via Gigabit connections. They run IBMOSA, which uses OSPF to route traffic to the rest of the network, mainly to detect and respondto Gigabit link failure. They connect directly to aggregation layer switches in one of the twoaggregation modules.Server Farm ModuleMainframe & website DMZ also located herex 8Internetx 8CoreAggregation Access Rows of racks of serversThe corporate public-facing web and e-commerce servers are in a DMZ complex connected toone pair of access switches in the server farm area. They produce a high volume of traffic, alllocal to the server module. Separate dedicated high-speed Internet connections connect to theoutside of the firewalls in the DMZ complex. All servers, mainframes, and web servers areduplicated at the second data center site.Hotels ModuleEach hotel connects via frame relay to each data center through the Hotels Module. There are16 access routers, each of which connects to approximately 128 hotels. They aggregate intofour pairs of aggregation routers, one pair for each of four Regions. The aggregation routersconnect to two Layer 3 switches at the core-facing edge of the Hotels Module. The data centeraccess router WAN links are fractional T3, running at approximately 20 (or 30) Mbps, one toeach access router. The hotels have 256 Kbps PVCs with fractional T1 access circuits.Hotels ModuleFrameRelayCoreAggregation (4 pairs)L2 connectivity(shared)Access (4 groupsof 4, 16 total)To 2000hotels12 Designing Cisco Network Service Architectures (ARCH) v2.0 © 2007 Cisco Systems, Inc.