As Citrix Synergy 2013 in Los Angeles is fast approaching, we are all working hard to ensure our partners and valued customers will enjoy and learn as much as possible during the show. If you are attending Synergy and interested in Cloud Computing, you are probably excited to see more sessions focused on Cloud Computing this year. One of these cloud focused sessions, SYN301: Architecting your cloud infrastructure, will be co-hosted by yours truly and Matt Mullins.
Matt and I come from different departments in Citrix Cloud Group. Matt is an extremely talented and experienced CloudPlatform Implementation Engineer from our Worldwide Cloud Services and I am a Sr. Sales Engineer in Citrix Cloud Platform Group. Matt represents the Post-Sale part of a Cloud project, while I focus on the Pre-Sale activities which include Proof-of-Concept (PoC) installations. We both hope you will be able to join our session where Matt and I will share our knowledge and experience on how to successfully architect your cloud infrastructure. You won’t want to miss this session, so make sure to add it to your agenda today!
Today I would like to share some lessons we have learned from hundreds of PoCs we have conducted at Citrix Cloud Platform Group.
One of the common questions we are asked is, “How long does it take to standup a Citrix CloudPlatform PoC”. My answer is always the same, “Anywhere between 20 minutes (yes, 20 minutes) to 20 days. It all depends on how well prepared you are.”
The area where we see the most delays and challenges is networking. The main reason for these challenges is primarily lack of understanding of Citrix CloudPlatform’s network options and the requirements needed for each network topology. This is nothing to be ashamed of, Citrix CloudPlatform and Cloud in general, introduces a new approach to networking and the learning curve can be a bit long, even for networking gurus.
Networking in Citrix CloudPlatform is very unique. The reason Citrix CloudPlatform (or Apache CloudStack) is so popular and successful is due to the fact that it supports multiple network models. Citrix CloudPlatform does not force companies to use specific network architecture for their cloud, instead it offers multiple models, which can fit different use cases.
The challenge is that each network model requires different network prerequisites, so the first step of a PoC deployment is to decide the network topology that will be used and prepare all the required elements. Here are some high level network concepts that will help you get started.
Citrix CloudPlatform Networking Concepts
There are several concepts that are important to understand when implementing Citrix CloudPlatform:
- Citrix CloudPlatform uses DHCP to manage and allocate IPs to instances. The Citrix CloudPlatform DHCP will only allocate IPs to instances based on their unique MAC address (we use a special MAC addresses with the prefix 06:X:X:X) – if another DHCP resides on the network, admins will need to exclude the Citrix CloudPlatform MAC addresses on this DHCP server and prevent it from assigning IP addresses to request with the 06:X MAC prefix.
- Basic Network does not support VLAN IDs while Advanced Networking requires VLAN IDs.
- In Advanced Networking, the most common issue we face is lack of proper configuration on the network switches. The network switches must be properly configured for VLAN trunking (802.1q).
- There are several traffic types used in Citrix CloudPlatform, depending on the network model used, evaluators will need to prepare different IP ranges (which cannot overlap and each must use different CIDR). For example, Basic Networking uses Management Traffic, Guest Traffic and optional Storage Traffic. Advanced Network requires Public Traffic, Management traffic, optional Storage traffic and Guest traffic (if using shared networks) if Isolated networks are used, the guest IPs will be managed by the Virtual Router).
- Basic Network is considered a more scalable network topology. Usually the limiting factor is the amount of Guest IPs admins assign. This will reflect how many instances can be deployed
- Advanced Networking is a feature-rich model, however, since it relies on VLAN IDs, a single zone can support up to ~4096 (known VLAN limit) – this will be addressed in the future as new isolation methods will be supported. Currently if an Advanced Zone has reached its VLAN limit, a new zone must be created.
Based on our experiences we have created a special Citrix CloudPlatform PoC Checklist Guide that explains the different network designs and what exactly is needed in order to setup a PoC. The guide also provides information on other elements such as storage, hypervisor specific requirements and general best practices and tips. A must read if you plan to evaluate Citrix CloudPlatform soon.
If you plan to start a Citrix CloudPlatform PoC don’t forget to download the PoC checklist guide. The guide is provided as part of the supporting documentation for Citrix CloudPlatform 90 Days Trial.
Matt and I are looking forward to seeing you at synergy!