How to get a F5 BIG-IP VE Developer Lab License
(applies to BIG-IP TMOS Edition) To assist DevOps teams improve their development for the BIG-IP platform, F5 offers a low cost developer lab license.This license can be purchased from your authorized F5 vendor. If you do not have an F5 vendor, you can purchase a lab license online: CDW BIG-IP Virtual Edition Lab License CDW Canada BIG-IP Virtual Edition Lab License Once completed, the order is sent to F5 for fulfillment and your license will be delivered shortly after via e-mail. F5 is investigating ways to improve this process. To download the BIG-IP Virtual Edition, please log into downloads.f5.com (separate login from DevCentral), and navigate to your appropriate virtual edition, example: For VMware Fusion or Workstation or ESX/i:BIGIP-16.1.2-0.0.18.ALL-vmware.ova For Microsoft HyperV:BIGIP-16.1.2-0.0.18.ALL.vhd.zip KVM RHEL/CentoOS: BIGIP-16.1.2-0.0.18.ALL.qcow2.zip Note: There are also 1 Slot versions of the above images where a 2nd boot partition is not needed for in-place upgrades. These images include_1SLOT- to the image name instead of ALL. The below guides will help get you started with F5 BIG-IP Virtual Edition to develop for VMWare Fusion, AWS, Azure, VMware, or Microsoft Hyper-V. These guides follow standard practices for installing in production environments and performance recommendations change based on lower use/non-critical needs fo Dev/Lab environments. Similar to driving a tank, use your best judgement. DeployingF5 BIG-IP Virtual Edition on VMware Fusion Deploying F5 BIG-IP in Microsoft Azure for Developers Deploying F5 BIG-IP in AWS for Developers Deploying F5 BIG-IP in Windows Server Hyper-V for Developers Deploying F5 BIG-IP in VMware vCloud Director and ESX for Developers Note: F5 Support maintains authoritativeAzure, AWS, Hyper-V, and ESX/vCloud installation documentation. VMware Fusion is not an official F5-supported hypervisor so DevCentral publishes the Fusion guide with the help of our Field Systems Engineering teams.BIG-IP Configuration Conversion Scripts
Kirk Bauer, John Alam, and Pete White created a handful of perl and/or python scripts aimed at easing your migration from some of the “other guys” to BIG-IP.While they aren’t going to map every nook and cranny of the configurations to a BIG-IP feature, they will get you well along the way, taking out as much of the human error element as possible.Links to the codeshare articles below. Cisco ACE (perl) Cisco ACE via tmsh (perl) Cisco ACE (python) Cisco CSS (perl) Cisco CSS via tmsh (perl) Cisco CSM (perl) Citrix Netscaler (perl) Radware via tmsh (perl) Radware (python)
A Brief Introduction To External Application Verification Monitors
Background EAVs (External Application Verification) monitors are one of most useful and extensible features of the BIG-IP product line. They give the end user the ability to utilize the underlying Linux operating system to perform complex and thorough service checks. Given a service that does not have a monitor provided, a lot of users will assign the closest related monitor and consider the solution complete. There are more than a few cases where a TCP or UDP monitor will mark a service “up” even while the service is unresponsive. EAVs give us the ability to dive much deeper than merely performing a 3-way handshake and neglecting the other layers of the application or service. How EAVs Work An EAV monitor is an executable script located on the BIG-IP’s file system (usually under /usr/bin/monitors) that is executed at regular intervals by the bigd daemon and reports its status. One of the most common misconceptions (especially amongst those with *nix backgrounds) is that the exit status of the script dictates the fate of the pool member. The exit status has nothing to do with how bigd interprets the pool member’s health. Any output to stdout (standard output) from the script will mark the pool member “up”. This is a nuance that should receive special attention when architecting your next EAV. Analyze each line of your script and make sure nothing will inadvertently get directed to stdout during monitor execution. The most common example is when someone writes a script that echoes “up” when the checks execute correctly and “down” when they fail. The pool member will be enabled by the BIG-IP under both circumstances rendering a useless monitor. Bigd automatically provides two arguments to the EAV’s script upon execution: node IP address and node port number. The node IP address is provided with an IPv6 prefix that may need to be removed in order for the script to function correctly. You’ll notice we remove the “::ffff://” prefix with a sed substitution in the example below. Other arguments can be provided to the script when configured in the UI (or command line). The user-provided arguments will have offsets of $3, $4, etc. Without further ado, let’s take a look at a service-specific monitor that gives us a more complete view of the application’s health. An Example I have seen on more than one occasion where a DNS pool member has successfully passed the TCP monitor, but the DNS service was unresponsive. As a result, a more invasive inspection is required to make sure that the DNS service is in fact serving valid responses. Let’s take a look at an example: #!/bin/bash # $1 = node IP # $2 = node port # $3 = hostname to resolve [[ $# != 3 ]] && logger -p local0.error -t ${0##*/} -- "usage: ${0##*/} <node IP> <node port> <hostname to resolve>" && exit 1 node_ip=$(echo $1 | sed 's/::ffff://') dig +short @$node_ip $3 IN A &> /dev/null [[ $? == 0 ]] && echo “UP” We are using the dig (Domain Information Groper) command to query our DNS server for an A record. We use the exit status from dig to determine if the monitor will pass. Notice how the script will never output anything to stdout other than “UP” in the case of success. If there aren’t enough arguments for the script to proceed, we output the usage to /var/log/ltm and exit. This is a very simple 13 line script, but effective example. The Takeaways The command should be as lightweight and efficient as possible If the same result can be accomplished with a built-in monitor, use it EAV monitors don’t rely on the command’s exit status, only standard output Send all error and informational messages to logger instead of stdout or stderr (standard error) “UP” has no significance, it is just a series of character sent to stdout, the monitor would still pass if the script echoed “DOWN” Conclusion When I first discovered EAV monitors, it opened up a whole realm of possibilities that I could not accomplish with built in monitors. It gives you the ability to do more thorough checking as well as place logic in your monitors. While my example was a simple bash script, BIG-IP also ships with Perl and Python along with their standard libraries, which offer endless possibilities. In addition to using the built-in commands and libraries, it would be just as easy to write a monitor in a compiled language (C, C++, or whatever your flavor may be) and statically compile it before uploading it to the BIG-IP. If you are new to EAVs, I hope this gives you the tools to make your environments more robust and resilient. If you’re more of a seasoned veteran, we’ll have more fun examples in the near future.
Sharing same VLAN between vCMP guest
Hello, This question is regarding to sharing same VLAN between vCMP guest for F5 viprion platform. lets say, I have a VLAN 10 which is tagged to interface 1.1 at vCMP host level and propagated to Guest A in common partition. -For the guest B can I use same VLAN? -What would be the recommend way to share VLANs between guests? -Can we tag VLAN 10 to 1.2 interface at vCMP host level and share it with Guest B?
F5 Predicts: Education gets personal
The topic of education is taking centre stage today like never before. I think we can all agree that education has come a long way from the days where students and teachers were confined to a classroom with a chalkboard. Technology now underpins virtually every sector and education is no exception. The Internet is now the principal enabling mechanism by which students assemble, spread ideas and sow economic opportunities. Education data has become a hot topic in a quest to transform the manner in which students learn. According to Steven Ross, a professor at the Centre for Research and Reform in Education at Johns Hopkins University, the use of data to customise education for students will be the key driver for learning in the future[1].This technological revolution has resulted in a surge of online learning courses accessible to anyone with a smart device. A two-year assessment of the massive open online courses (MOOCs) created by HarvardX and MITxrevealed that there were 1.7 million course entries in the 68 MOOC [2].This translates to about 1 million unique participants, who on average engage with 1.7 courses each. This equity of education is undoubtedly providing vast opportunities for students around the globe and improving their access to education. With more than half a million apps to choose from on different platforms such as the iOS and Android, both teachers and students can obtain digital resources on any subject. As education progresses in the digital era, here are some considerations for educational institutions to consider: Scale and security The emergence of a smogasborad of MOOC providers, such as Coursera and edX, have challenged the traditional, geographical and technological boundaries of education today. Digital learning will continue to grow driving the demand for seamless and user friendly learning environments. In addition, technological advancements in education offers new opportunities for government and enterprises. It will be most effective if provided these organisations have the ability to rapidly scale and adapt to an all new digital world – having information services easily available, accessible and secured. Many educational institutions have just as many users as those in large multinational corporations and are faced with the issue of scale when delivering applications. The aim now is no longer about how to get fast connection for students, but how quickly content can be provisioned and served and how seamless the user experience can be. No longer can traditional methods provide our customers with the horizontal scaling needed. They require an intelligent and flexible framework to deploy and manage applications and resources. Hence, having an application-centric infrastructure in place to accelerate the roll-out of curriculum to its user base, is critical in addition to securing user access and traffic in the overall environment. Ensuring connectivity We live in a Gen-Y world that demands a high level of convenience and speed from practically everyone and anything. This demand for convenience has brought about reform and revolutionised the way education is delivered to students. Furthermore, the Internet of things (IoT), has introduced a whole new raft of ways in which teachers can educate their students. Whether teaching and learning is via connected devices such as a Smart Board or iPad, seamless access to data and content have never been more pertinent than now. With the increasing reliance on Internet bandwidth, textbooks are no longer the primary means of educating, given that students are becoming more web oriented. The shift helps educational institutes to better personalise the curriculum based on data garnered from students and their work. Duty of care As the cloud continues to test and transform the realms of education around the world, educational institutions are opting for a centralised services model, where they can easily select the services they want delivered to students to enhance their learning experience. Hence, educational institutions have a duty of care around the type of content accessed and how it is obtained by students. They can enforce acceptable use policies by only delivering content that is useful to the curriculum, with strong user identification and access policies in place. By securing the app, malware and viruses can be mitigated from the institute’s environment. From an outbound perspective, educators can be assured that students are only getting the content they are meant to get access to. F5 has the answer BIG-IP LTM acts as the bedrock for educational organisations to provision, optimise and deliver its services. It provides the ability to publish applications out to the Internet in a quickly and timely manner within a controlled and secured environment. F5 crucially provides both the performance and the horizontal scaling required to meet the highest levels of throughput. At the same time, BIG-IP APM provides schools with the ability to leverage virtual desktop infrastructure (VDI) applications downstream, scale up and down and not have to install costly VDI gateways on site, whilst centralising the security decisions that come with it. As part of this, custom iApps can be developed to rapidly and consistently deliver, as well as reconfigure the applications that are published out to the Internet in a secure, seamless and manageable way. BIG-IP Application Security Manager (ASM) provides an application layer security to protect vital educational assets, as well as the applications and content being continuously published. ASM allows educational institutes to tailor security profiles that fit like a glove to wrap seamlessly around every application. It also gives a level of assurance that all applications are delivered in a secure manner. Education tomorrow It is hard not to feel the profound impact that technology has on education. Technology in the digital era has created a new level of personalised learning. The time is ripe for the digitisation of education, but the integrity of the process demands the presence of technology being at the forefront, so as to ensure the security, scalability and delivery of content and data. The equity of education that technology offers, helps with addressing factors such as access to education, language, affordability, distance, and equality. Furthermore, it eliminates geographical boundaries by enabling the mass delivery of quality education with the right policies in place. [1] http://www.wsj.com/articles/SB10001424052702304756104579451241225610478 [2] http://papers.ssrn.com/sol3/papers.cfm?abstract_id=2586847Is TCP's Nagle Algorithm Right for Me?
Of all the settings in the TCP profile, the Nagle algorithm may get the most questions. Designed to avoid sending small packets wherever possible, the question of whether it's right for your application rarely has an easy, standard answer. What does Nagle do? Without the Nagle algorithm, in some circumstances TCP might send tiny packets. In the case of BIG-IP®, this would usually happen because the server delivers packets that are small relative to the clientside Maximum Transmission Unit (MTU). If Nagle is disabled, BIG-IP will simply send them, even though waiting for a few milliseconds would allow TCP to aggregate data into larger packets. The result can be pernicious. Every TCP/IP packet has at least 40 bytes of header overhead, and in most cases 52 bytes. If payloads are small enough, most of the your network traffic will be overhead and reduce the effective throughput of your connection. Second, clients with battery limitations really don't appreciate turning on their radios to send and receive packets more frequently than necessary. Lastly, some routers in the field give preferential treatment to smaller packets. If your data has a series of differently-sized packets, and the misfortune to encounter one of these routers, it will experience severe packet reordering, which can trigger unnecessary retransmissions and severely degrade performance. Specified in RFC 896 all the way back in 1984, the Nagle algorithm gets around this problem by holding sub-MTU-sized data until the receiver has acked all outstanding data. In most cases, the next chunk of data is coming up right behind, and the delay is minimal. What are the Drawbacks? The benefits of aggregating data in fewer packets are pretty intuitive. But under certain circumstances, Nagle can cause problems: In a proxy like BIG-IP, rewriting arriving packets in memory into a different, larger, spot in memory taxes the CPU more than simply passing payloads through without modification. If an application is "chatty," with message traffic passing back and forth, the added delay could add up to a lot of time. For example, imagine a network has a 1500 Byte MTU and the application needs a reply from the client after each 2000 Byte message. In the figure at right, the left diagram shows the exchange without Nagle. BIG-IP sends all the data in one shot, and the reply comes in one round trip, allowing it to deliver four messages in four round trips. On the right is the same exchange with Nagle enabled. Nagle withholds the 500 byte packet until the client acks the 1500 byte packet, meaning it takes two round trips to get the reply that allows the application to proceed. Thus sending four messages takes eight round trips. This scenario is a somewhat contrived worst case, but if your application is more like this than not, then Nagle is poor choice. If the client is using delayed acks (RFC 1122), it might not send an acknowledgment until up to 500ms after receipt of the packet. That's time BIG-IP is holding your data, waiting for acknowledgment. This multiplies the effect on chatty applications described above. F5 Has Improved on Nagle The drawbacks described above sound really scary, but I don't want to talk you out of using Nagle at all. The benefits are real, particularly if your application servers deliver data in small pieces and the application isn't very chatty. More importantly, F5® has made a number of enhancements that remove a lot of the pain while keeping the gain: Nagle-aware HTTP Profiles: all TMOS HTTP profiles send a special control message to TCP when they have no more data to send. This tells TCP to send what it has without waiting for more data to fill out a packet. Autonagle:in TMOS v12.0, users can configure Nagle as "autotuned" instead of simply enabling or disabling it in their TCP profile. This mechanism starts out not executing the Nagle algorithm, but uses heuristics to test if the receiver is using delayed acknowledgments on a connection; if not, it applies Nagle for the remainder of the connection. If delayed acks are in use, TCP will not wait to send packets but will still try to concatenate small packets into MSS-size packets when all are available. [UPDATE:v13.0 substantially improves this feature.] One small packet allowed per RTT: beginning with TMOS® v12.0, when in 'auto' mode that has enabled Nagle, TCP will allow one unacknowledged undersize packet at a time, rather than zero. This speeds up sending the sub-MTU tail of any message while not allowing a continuous stream of undersized packets. This averts the nightmare scenario above completely. Given these improvements, the Nagle algorithm is suitable for a wide variety of applications and environments. It's worth looking at both your applications and the behavior of your servers to see if Nagle is right for you.
