Cisco Cisco Prime Network Services Controller 3.2 White Paper

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Figure 11. Secure Out-of-Band Management Network for Hosted Cloud VMs

Full Redundancy in Any VDC

In the logical creation of a VDC, the implementation of high availability is crucial. Every component of the

infrastructure (network and services) has a redundant mate on the underlying physical devices; this should be

accommodated by automation tools - building HA configuration into the logical VDC for both redundancy and better

utilization of links in the provider infrastructure. From our experience active-active deployment of the HA

configuration is highly appreciated as it allows utilizing all available bandwidth on the infrastructure.

HA should be an attribute of a VDC at the zone level.

In order to allow service providers to utilize all available links and all available bandwidth on a particular PoD, the

automation will be building, by default, an active-active logical construction of a VDC. We recommend doing that

using Tenant-ID:VDC-ID for load-balancing between different redundant devices.

The creation of an active-

active logical design will be done by using the device’s HA mechanism, such as Hot

Standby Router Protocol (HSRP), Virtual Router Redundancy Protocol (VRRP), or any other First Hop

Redundancy Protocol (FHRP) technology used by networking and services devices like switches, routers, firewalls,

and load balancers. Each device might use different ways to configure the HA feature. In all cases there are

methods to define who will be the primary for a specific network and what is the IP address to use as the next hop.

We suggest that Tenant-ID:VDC-ID be divided into odd and even IDs so different VDCs will use different paths

accordingly. The odd VDC will be built using primary devices on one side of the infrastructure; the even VDC will

be built using primary devices on the other side of the infrastructure. Detailed templates for this design will be

introduced in such a way that the ID to be used for path selection could be changed (into active-passive setup or

into a different mechanism for path selection) by allowing service provider administrators to change the VDC IDs

and the priority of run-time variables that are created for it.