Hyper-V ConceptsIt's time to get familiar with Hyper-V Virtualization, virtual servers, virtual switches, virtual CPUs, virtual deployment infrastructure (VDI) and more.
If you are reading this you have heard about the Cloud Computing. If not, I would be worried! Terms such as Cloud Computing, Software as a Service, Cloud Storage has become a permanent fixture in adverts, marketing content and technical documentation.
Many Windows desktop software applications have moved to the “cloud”. Though, even though the whole industry wants you and your data in the cloud, have you ever looked into the pros and cons of the cloud? Does it make sense to go into that direction?
Let’s use web application security scanners as an example, software that is used to automatically identify vulnerabilities and security flaws in websites and web applications. Most, if not all of the industry leading vendors have both a desktop edition and an online service offering. In fact Netsparker just launched their all new service offering; Netsparker Cloud, the online false positive free web application security scanner. In such case which one should you go for?
As clearly explained in Netsparker Desktop VS Netsparker Cloud both web security solutions are built around the same scanning engine, hence their vulnerability detection capabilities are the same. The main differences between both of them are the other non-scan related features, which also define the scope of the solution.
With the release of Hyper-V vNext just around the corner, Altaro has organized a Free webinar that will take you right into the new Hyper-V vNext release. Microsoft Hyper-V MVP, Aidan Finn and Microsoft Sr. Technical Evangelist Rick Claus will take you through the new features, improvements, changes and much more, and will be available to answer any questions you might have.
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Date & Time: Thursday, 26th March 2015 at 4PM CET / 11am EDT / 8am PDT
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Our previous article introduced Cisco’s popular Wireless Controller (WLC) devices and examined their benefits to enterprise networks, different models offered and finally took a look at their friendly GUI interfaces. This article continues by explaining the purpose and functionality of each WLC interface (Management interface, Virtual interface, AP-Manager interface, Dynamic interfaces etc), WLC Port (Service port, Redundant port, Distribution ports etc), how WLCs connect to the network infrastructure, VLAN requirements and mapping to SSIDs.
Users can freely download Cisco's WLC product portfolio in our Cisco's Wireless Controller Datasheets download section. The datasheets contain all currently available WLC models, brief specification overview/comparison and much more.
Every WLC is fitted with a number of ports (physical interfaces) and logical interfaces, all critical for the device’s proper operation and integration with the network infrastructure. It is important that engineers working with WLCs, understand the purpose of each interface and how it should be used. This will help maximize the stability and scalability of any WLC deployment by correctly configuring all necessary interfaces and attached devices.
We will now take a look at the different ports that can be found on WLCs and explain their purpose. Depending on the WLC model, some ports might or might not be present. The Console Port and Distribution System Ports are found on all WLCs.
Figure 1. Available Ports on a Cisco WLC 5500
This port is used for High-Availability (HA) deployment designs when there are two WLCs available. In this setup, both WLCs are physically connected with each other through the Redundant Port using an Ethernet cable. The redundancy port is used for configuration, operational data synchronization and role negotiation between the primary and secondary controllers.
The redundancy port checks for peer reachability by sending UDP keepalive messages every 100 milliseconds from the standby-hot WLC to the active WLC. Finally, the first two octets of the redundancy port’s IP address is always 169.254.xxx.xxx.
The service port is used for out-of-band management of the controller and system recovery and maintenance in the event of a network failure. It is important to note that the service port does not support VLAN trunking or VLAN tagging and is therefore required to connect to an access port on the switch.
It is also recommended not to connect the service port to the same VLAN as the wired clients network because by doing so, administrators will not be able to access the management interface (analysed later) of the controller.
SFP/Ethernet Distribution System Ports
The distribution system ports are the most important ports on the WLC as they connect the internal logical interfaces (analysed below) and wireless client traffic to the rest of our network. High-end WLCs as the WLC 5500 series above, have multiple SFP-based distribution system ports allowing engineers to connect the WLC with the network backbone using different configurations. The SFP Ports are able to accept fiber optic or Ethernet copper interfaces, with the use of the appropriate SFPs.
Figure 2. Picture of Fiber & Ethernet Copper SFPs
Lower-end WLCs such as the WLC2504 or the older WLC2100 series provide Ethernet interfaces only, because of the limited number of access points supported. For example, the WLC2504 provides up to 4 Gigabit Ethernet ports and can support up to 75 access points, while the WLC2125 provides up to 8 FastEthernet ports and supports up to 25 access points.
Figure 3. Pictures of WLC2504 & WLC2124
In this section, we will examine the logical interfaces that can be found on all WLCs. Understanding the functionality of each logical interface is crucial for the correct setup and deployment of any Cisco WLC-based wireless network.
The Cisco Wireless Controller (WLC) series devices provide a single solution to configure, manage and support corporate wireless networks, regardless of their size and locations. Cisco WLCs have become very popular during the last decade as companies move from standalone Access Point (AP) deployment designs to a centralized controller-based design, reaping the enhanced functionality and redundancy benefits that come with controller-based designs.
Cisco currently offers a number of different WLC models, each targeted for different sized networks. As expected, the larger models (WLC 8500, 7500, 5760 etc) offer more high-speed gigabit network interfaces, high availability and some advanced features required in large & complex networks, for example supporting more VLANs and WiFi networks, thousands of AP & Clients per WLC device and more.
Recently, Cisco has begun offering WLC services in higher-end Catalyst switches by embedding the WLC inside Catalyst switches e.g Catalyst 3850, but also as a virtual image 'Virtual WLC' that runs under VMware ESX/ESXi 4.x/5.x. Finally Cisco ISR G2 routers 2900 & 3900 series can accept Cisco UCS–E server modules, adding WLC functionality and supporting up to 200 access points and 3000 clients.
Figure 1. A few of the larger Cisco WLC models and Catalyst 3850
More detailed information on the current available models and their specifications can be obtained from our Cisco Wireless Controller Product and Datasheet section and freely download WLC datasheets containing each model’s features, deployment modes, supported VLANs, maximum access points & clients, encryption features, wireless standards support (802.11xx) and many more.
Learn about WLC interfaces, their physical and logical ports, how they connect to the network and how Wireless SSIDs are mapped to VLAN interfaces, plus much more, in our Cisco WLC Interfaces, Ports & Their Functionality. Understand How WLCs Work, Connect to the Network Infrastructure & Wi-Fi SSID/VLAN mappings article.
While all WLC models support GUI and CLI based configuration, in contrast with Cisco routers and switches which are usually configured via CLI, WLCs are most often configured via their nicely designed web GUI. The CLI is mandatory only during the initial configuration, where the engineer is required to assign an IP address to the WLC device, along with a few other important parameters.
Working with any WLC model gives the engineer a great advantage as the interface is identical across all WLC models, making it easy to manage and configure, regardless of the WLC model:
Figure 2. Cisco WLC 8500 (left) and Cisco WLC 2500 (right) web interface
Unlike other Cisco products, the WLC’s GUI interface is extremely well designed with a logical layout.
When logging into the WLC GUI, the administrator is presented with a healthy amount of information, including a front view of the controller from where he can see the status of each physical port and more details which we’ll be looking into right now.
We would like to inform our readers that Firewall.cx has just made available as a free download all of Cisco's Wireless Controller Datasheets.
The datasheets provide valuable infomation for all currently available Cisco Wireless Controllers including:
Readers can head directly to our Cisco Product Datasheets & Guides where they can find the Cisco Wireless Controllers (WLC) Datasheet section amongst other Cisco products.