Customers in Switch data centers are provided a number of different options for Internet connectivity. These range from single drops, to multiple redundant drops. Redundancy to the customer is provided either by BGP (Border Gateway Protocol) or HSRP (Hot Standby Routing Protocol). Below are a few examples.
BGP Example A
BGP, Border Gateway Protocol, is currently the most appropriate routing protocol to be placed between different systems. In this example a firm demarcation is created between the systems while avoiding a single point of failure. Only a handful of routes need be exchanged between the systems keeping complexity at a minimum.
HSRP Example A
HSRP, Hot Standby Routing Protocol, is a mechanism to provide a redundant gateway for connected devices. In this example, the redundant gateway is provided to all servers. This example still contains a single point of failure in the customer switch. Failure of this device will render the HSRP gateway inaccessible.
HSRP Example B
In this next example, we use a seemingly small – but highly important modification from Example A (above). Here, a router is placed behind the switch. The result is a clear and vital improvement, a demarcation is declared between the two systems; however, failure of either device will render the HSRP gateway inaccessible.
HSRP Example C
This example eliminates a single point of failure and promotes the greatest possible uptime. Additionally, HSRP, or equivalent, can be run across the switches from the customer routers to provide a redundant destination for Switch to route to.
Single Connection A
BGP, Border Gateway Protocol, is currently the most appropriate routing protocol to be placed between different systems. In this example a firm demarcation is created between the systems while avoiding a single point of failure. Only a handful of routes need be exchanged between the systems keeping complexity at a minimum.
Single Connection B
This connection is the simplest way to take advantage of the Switch blended IP product. The positioning of a router is the preferred method as it creates a firm demarcation. This demarcation allows for expansion much more easily as well. However, like the A example, it is also the most susceptible to interruption from maintenance or failure.