I previously discussed using LISP to optimize your client-server traffic so today I’ll discuss the reverse direction: Egress Path Optimization from the Server to the Client. Let’s go over the need for Path Optimization in the direction from Server-to-Client with some pictures and explanations.
The Virtual Machine (VM) server is configured with a default gateway IP address, 192.168.1.1, which is the next hop IP address that the VM will forward packets towards as the traffic returns to the client outside the data center. In this data center environment, we’ve deployed the default gateway using the First Hop Redundancy Protocol (FHRP). In reality, FHRP is an umbrella technology term that includes Hot Standby Routing Protcol (HSRP) and Virtual Router Redundancy Protocol (VRRP), two main technologies that provide transparent failover and redundancy at the first hop IP router. Please see info on FHRP here.
Also notice that the VM default gateway is the same as the HSRP Virtual IP Address (VIP). The HSRP VIP binds itself to one of the physical HSRP Routers via an HSRP election process using Layer 2 control packets between the two physical HSRP Routers and this means that the VM default gateway, since it points to a VIP, may move between physical HSRP Routers, and of course which is then intent and design when using any type of FHRP.
In the above picture, the Path is Optimized from Server to Client, so now let’s take a look at what happens when we migrate the VM to the new data center.
Update: LISP solves the problem from client to server, IE Ingress Path Optimization. FHRP solves the problem from server to client, IE Egress Path Optimization. You can check out Egress Path Optimization here.
We recently published a Data Center Interconnect – DCI- related document on cisco.com and I wanted to get it in front of you. Locator/Identifier Separator Protoc0l – LISP – provides the path optimization technology to forward transactions via the most direct path, ultimately meaning better application performance. The link for the LISP Virtual Machine Mobility paper is below.
As a side note, LISP can be used many other ways and here’s a pointer to one of our LISP pages.
For our purposes in DCI, we use LISP for path optimization and we can see here why the need arises. The box on the left shows an existing transaction that looks pretty direct. The middle box shows the workload is now in a new data center but the transaction is suboptimal, it still goes through the firsts data center. The box on the right shows the desired path, the direct path from user to workload withouth going through the first data center. It’s pretty easy to see the need here for path optimization and the desire to have the direct path to the new data center location as shown on the far right box.
Making it Easier to Deploy and Enhance Cloud Infrastructure
Open standards. Open ecosystem. Needs for higher bandwidth. Needs for greater levels of security. Faster application response times. Demand for new levels of flexibility in moving from legacy Data Center architectures to Cloud Computing models. At Cisco, we hear these demands from our customers and partners every day as we deliver solutions to help them drive greater productivity into their business.
But we realize that we can’t deliver innovative solutions to the market alone. Not only do we need to work with partners that create world-class technology, but we need partners that are committed to creating intelligent environments that drive participation from every part of the market.
Today Intel launched the Intel Cloud Builder program, part of it’s broader Cloud 2015 initiative. This multi-vendor initiative is committed to helping customers as they migrate to various forms of Cloud Computing. Intel Cloud Builder brings together industry leaders to drive new innovations, to educate customers about technology and trends, and to deliver solutions (via Reference Architectures) that can be deployed today.
I suppose that I could have titled this blog post as, “The Value of the Network for Cloud Computing”, but I wanted to focus on the viewpoints that I often hear from end-users or application owners. They tend to look at the network as a conduit to their information, and the bigger the pipe the better. The “bandwidth is more important than oxygen” theory. While I can obviously understand this viewpoint from groups that consume the network from the perspective of bandwidth, it’s important to remember that the network is the fundamental element that allows Cloud Computing (Public, Private or Hybrid) to exist in the first place.
So let’s talk about some of the myths and misunderstandings around Cloud and the network… Read More »