1. Why do you need to deploy load balancing?

➤Inefficiencies, delays, and failures in application delivery can cost millions of dollars in wasted budgets, damaged corporate reputation, system and application downtime, legal liability, and missed opportunities. BIG-IP Local Traffic Manager (LTM) is the premier application traffic management system that provides the industry's smartest solution to secure, optimize, and deliver applications, enabling businesses to remain operationally efficient while increasing their competitiveness. It includes a complete system of unified application infrastructure services, which combines overall control, visibility and flexibility into application security, performance and delivery.

➤The role of your network is to deliver applications and services, but as your business needs change and grow, you may need more complex and expensive infrastructure to meet those needs. BIG-IP® Local Traffic Manager (LTM) transforms your network into a flexible application delivery infrastructure. It is a full proxy between the user and the application server, creating a layer for securing, optimizing and load balancing application traffic. This gives you complete control over your network, allowing you to easily add servers, eliminate business disruption, improve application performance, and meet security requirements.

➤Managing application delivery across multiple networks is a complex issue. Organizations try to deal with this complexity in different ways: buying more bandwidth, installing more servers, or even rewriting applications. However, these strategies are often expensive and only partially effective. Deploying the F5-BIG-LTM-I2800 product is often less costly and enables more immediate and efficient problem solving.

➤The F5 BIG-IP Application Delivery Controller (ADC) platform can simultaneously manage heavier traffic loads from layer 4 to layer 7 . By merging high-performance switching fabrics, purpose-built hardware, and advanced software, F5 has the flexibility to make application-depth decisions without creating bottlenecks. With the high performance of the BIG-IP platform, you can consolidate devices—saving management costs as well as power, space, and cooling—and still have room to grow.

2. Main advantages

Integrating infrastructure with dedicated hardware
The BIG-IP hardware platform is designed specifically for application delivery performance and scalability. The appliance can be configured for server load balancing, global data center load balancing, DNS serving, web application firewall, access management, web performance optimization, and WAN optimization.
Offloading Application Servers
The BIG-IP platform employs high-performance SSL and compression hardware and advanced connection management to offload processing-intensive tasks from application servers, consolidate devices, and improve resource usage efficiency.
Ensure Network Security
Instantly add layer 3-7 protection with the ICSA-certified BIG-IP platform; the platform offers default deny security, a complete packet filtering engine that supports fine-grained access restrictions, and an industry-leading web application firewall.
Reduce Operating Costs
BIG-IP hardware platforms provide out-of-band management, front-panel management, warm upgrades, remote boot, and USB support, while management is simple, helping to reduce the time spent on configuration, upgrades, and maintenance. Reduce power and cooling costs with 80 Plus Gold and Platinum certified high-efficiency power supplies. Maximum
uptime

Ensure critical infrastructure is built on a solid hardware foundation with hot-swappable components, redundant power supplies, CompactFlash cards, multi-boot support, and always-on management. Appliances can be deployed in a traditional active/standby configuration or in a horizontal cluster (active/active) configuration for high availability and application-level failover.

Superior Intelligent Performance
The traditional measure of performance is throughput, but throughput is an inaccurate representation of complex application delivery requirements. Connection capacity and L7 transactions per second are critical for ADCs to support the ever-increasing demands of contemporary web applications and infrastructure. For example, ADCs need to be able to handle high-level layer 4 and layer 7 connections and make more decisions at the application layer, such as detecting and removing sensitive information or transforming application-specific payloads. BIG-IP appliances provide the intelligence and performance to deliver a greater number of application-layer decisions while keeping data and infrastructure secure .

3. Simplify your network

BIG-IP ADC appliances help you simplify your network by offloading servers and consolidating equipment, saving data center management costs as well as power, space, and cooling costs. With the high performance and scalability of the BIG-IP platform, you can reduce the number of application delivery controllers required to deliver even more demanding applications. By offloading computationally intensive processes, you can greatly reduce the number of application servers required.

BIG-IP hardware includes:

➤SSL Hardware Acceleration— Offload costly SSL processing and speed up key exchange and bulk encryption with the best on the market .
➤Hardware Compression* — Cost-effectively offloads the server's traffic compression processing, resulting in faster page load times and less bandwidth usage.
➤OneConnect™ Connection Pooling—Aggregate millions of TCP requests into hundreds of server-side connections. Increase server capacity and ensure efficient processing of requests.
➤Embedded Packet Acceleration (ePVA)—provides specific application delivery optimization, supports low latency and tunneling protocols, and provides denial of service (DoS) attack protection. ePVA uses Field Programmable Gate Array (FPGA) technology, which is tightly integrated with TMOS and the software to be delivered:
➤High -performance interconnection between Ethernet port and processor.
➤ L4 offload to support leading throughput and reduce software load.
➤Hardware accelerated SYN FLOOD protection.
➤Detect and mitigate more than 65 DoS attacks in hardware.
➤ Native Financial Information Exchange (FIX) support for message routing and label replacement while maintaining low latency requirements.

Fourth, the advantages of F5 BIG-IP technology

F5-BIG-LTM-I2800 provides a unique architecture and patented hardware and software innovations, with unparalleled features, including:

F5 ScaleN Architecture
ScaleN supports on-demand performance scaling, virtualization, or horizontal clustering of multiple BIG-IP devices to create a resilient application delivery network infrastructure that can be efficiently adjusted as business needs change.
➤Scale on demand

Increase capacity and performance through on-demand scaling, which enables processing power to be added directly to existing infrastructure without adding equipment. New BIG-IP appliance models can be upgraded to higher performing models in each series through on-demand software licenses. With on-demand licensing, organizations can right-size application delivery services to support growth without adding new hardware.
➤Operational expansion

● F5 uses a multi-tenant architecture for application delivery controller (ADC) service virtualization; this architecture can support various BIG-IP versions and product modules on a single device. Multi-tenant device virtualization is provided by F5's unique Virtual Cluster Multiprocessing (vCMP®) technology, which allows a choice of hardware platforms to run multiple BIG-IP guest instances. Each BIG-IP guest instance behaves like a physical BIG-IP device, with dedicated CPU, memory, and other resources allocated.
● Each vCMP guest can be further partitioned using multi-tenancy features such as partitioning and routing domains to isolate configuration and networking by virtual domains. Within each virtual domain, administrative controls can be enforced using a role-based access system to further isolate and protect configuration and policies. By combining routing domains/partitions with vCMP guests, F5 enables a higher
● Using this ability to virtualize BIG-IP ADC services, service providers and enterprise users can be , enabling departmental or project-based tenancy with performance guarantees while gaining management of a single consolidated Application delivery platform and the benefits of increased utilization.
➤application extension

● Increase capacity by adding BIG-IP resources using a full-activation approach. With application scaling, you can move beyond traditional device pairs and avoid costly idle standby resources. Application expansion achieves this goal through two kinds of horizontal expansion: one is application service clustering, which focuses on application scalability and high availability; the other is device service clustering, which aims to efficiently and seamlessly expand BIG-IP applications delivery service.
● Through the clustering of application services, sub-second failover and comprehensive connection mirroring can be realized for high-availability clusters of up to eight devices on the application layer, so as to realize multi-tenant deployment with high availability. Workloads can move across appliances or clusters of virtual instances without disrupting other services, and can scale to meet business needs. Device Service Clustering can synchronize the entire device configuration in an all-active deployment model, enabling consistent policy deployment and enforcement across devices (up to 32 active nodes). This ensures consistent device configuration, which simplifies operations.

At the heart of the F5 TMOS Platform
BIG-IP appliance is the F5 operating system, TMOS®, which provides a unified system for better application delivery, giving you complete visibility and flexible control over all services. With TMOS, you can intelligently adapt to diverse and evolving application and network requirements.

F5 SYN Check
F5 supports both software SYN cache and hardware SYN cookie methods to prevent large-scale SYN FLOOD DDoS attacks. All TMOS platform software has a function to mitigate SYN FLOOD. Some hardware platforms (5000, 7000, 10000, and 12000 series appliances and VIPRION blade servers) can take advantage of embedded packet acceleration (ePVA) field programmable gate arrays (FPGAs) to greatly increase performance (up to 80 million SYN cookies). When a SYN FLOOD is detected, ePVA turns on the SYN Check™ feature, preventing invalid sessions from entering the server or draining BIG-IP device resources. The unique feature of SYN Check is that it can be applied by virtual IP/application, that is, if one application is attacked, other applications will not be affected. The F5 is the only ADC that implements hardware-based SYN cookies in both L4 and fully proxy L7 modes.

Next-Generation ADC Devices
With the introduction of the new BIG-IP 2000, 4000, 5000, 7000, 10000 and 12000 series devices, F5 continues to invest and innovate in hardware development to ensure that even the most demanding web applications can Available, safe and fast. The new BIG-IP hardware delivers industry-leading application performance in terms of application decisions per second, SSL processing, and hardware compression for each type of ADC. Enterprises and service providers can deploy multiple application delivery services, offload SSL processing, and efficiently consolidate on a single unified platform. In addition, with the ability to upgrade from the base unit to higher capacity models in the series through a software license, the F5 provides on-demand flexibility to keep pace with changing business needs.

5. F5-BIG-LTM-I2800 technical parameters

The following are the main functions of F5 load balancing F5-BIG-LTM-I2800 used as HTTP load balancer: The official name of F5 BIG-IP LTM is local traffic manager, which can do 4-7 layer load balancing, with Switching, Session Switching, Status Monitoring, Intelligent Network Address Translation, Generic Persistence, Response Error Handling, IPv6 Gateway, Advanced Routing, Smart Port Mirroring, SSL Acceleration, Smart HTTP Compression, TCP Optimization, Layer 7 Rate Shaping, Content Buffering, Content conversion, connection acceleration, cache, cookie encryption, selective content encryption, application attack filtering, denial of service (DoS) attack and SYN Flood protection, firewall - packet filtering, packet disinfection and other functions.

① F5 BIG-IP provides 12 flexible algorithms to distribute all traffic to each server in a balanced manner, while facing users, it is just a virtual server.

② F5 BIG-IP can confirm whether the application can return the corresponding data to the request. If a server behind the F5 BIG-IP has a failure such as service stop, crash, etc., F5 will check it out and mark the server as down , so as not to transmit the user's access request to the failed server. In this way, as long as other servers are normal, the user's access will not be affected. Once the downtime is repaired, F5 BIG-IP will automatically verify that the application has Be able to respond correctly to client requests and resume transmission to that server.

③﹤F5 BIG-IP has a dynamic Session session hold function.

④ The iRules function of F5 BIG-IP can filter HTTP content, and send access requests to different servers according to different domain names and URLs.

Next, combine the example to configure the F5-BIG-LTM-I2800 v9.x load balancer:

① As shown in the figure, assume that the domain name blog.s135.com is resolved to the external network/public virtual IP of the F5 load balancer: 61.1.1.3 (vs_squid), and there is a server pool (pool_squid) under the virtual IP. Contains two real Squid servers (192.168.1.11 and 192.168.1.12)

②If the Squid cache misses, it will request F5's intranet virtual IP: 192.168.1.3 (vs_apache). There is a default server pool (pool_apache_default) under this virtual IP, which contains two real Apache servers (192.168 .1.21 and 192.168.1.22), when the virtual IP matches the iRules rule, it will access another server pool (pool_apache_irules), which also contains two real Apache servers (192.168.1.23 and 192.168.1.24)

③ In addition, the default gateway of all real servers points to the internal network IP of the F5 load balancer, namely 192.168.1.2

④ All real servers access the Internet through the SNAT IP address 61.1.1.4