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DNS High Availability and Scalability Solutions

The requirements for availability, performance, scalability and security are of the highest concern for Domain Name System (DNS) services, which are at the foundation of all IP-based application services. All IP application access starts with DNS servers resolving service names to IP addresses so that end users can send emails, access web pages, place VoIP calls, and otherwise use a wealth of network services, transparently and easily. DNS downtime results in downtime for all IP access and services. Slow performance and poor response time have an immediate and noticeable impact on all customers. Many service providers and large enterprises now realize the need for resilient and scalable DNS infrastructures after experiencing prolonged service outages and slowdowns. To ensure business viability and sustainability, leading organizations are upgrading their DNS infrastructure by combining best-in-class DNS servers and load balancing switches. Foundry ServerIron DNS load balancing and security solution is an integral part of the world's largest DNS deployments to provide carrier-class availability, superior performance to millions of users and robust protection from attacks common against DNS servers.

Overview

Foundry is a leader in load balancing solutions for the world's most demanding service providers like Comcast, BellSouth, America Online, NTT DoCoMo, British Telecom, and Yahoo, delivering non-stop DNS and other IP/Web services at peak performance. The ServerIron family of load balancers leads the market in intelligence, performance, security and price. With Foundry's innovative network-centric design, high-performance architecture and comprehensive intelligence, the ServerIron switches deliver high-speed DoS attack protection, superior performance, maximum availability and unprecedented scalability to DNS and IP/Web services.

The Foundry switches feature best-of-breed intelligence to maximize server utilization, protect capital investment, and allow for infrastructure growth on demand. The ServerIron switches act as traffic cops in front of the DNS servers, and ensure high service uptime and superior scalability. They efficiently distribute client requests to the "best" server in the pool. The switches consider server availability, load and response time in server selection to provide the best end-user response time and service availability. Using sophisticated "health checks" to DNS servers, the ServerIron switches identify unavailable resources in real time and switch users to other available servers. They also help scale server farms on demand by adjusting server capacity without impacting application availability. When more capacity is needed, a new server can simply be added to the pool without impacting the end user. The ServerIron switches feature advanced modes of high availability to extend service resilience across the failures of a ServerIron switch. In the high availability mode, two ServerIron switches are deployed to back each other up during failures.

Foundry's ServerIron delivers scalable performance of up to 250,000 DNS queries/sec using stateful load balancing, and over 1.4 million queries/sec using stateless load balancing.

As a critical foundation for IP services, DNS servers are frequent targets of malicious attacks. The servers can be overloaded by DNS traffic from virus and worm propagation. Foundry ServerIron adds a layer of security protection and resilience against attacks in front of the DNS servers. The ServerIron features DNS rate limiting, filtering, and access policy enforcement to block many attacks. The performance "headroom" and inherent scalability offered by the solution results in a DNS infrastructure capable of withstanding dramatic traffic peaks due to attacks without sacrificing response time and uptime for legitimate users.

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Related Products

Foundry's application switching solutions are available on a range of ServerIron products purpose-built with ASIC-based and network-centric architecture to deliver highest availability, performance and scalability when deployed in business-critical application infrastructures. The ServerIron family of products feature the high-intelligent TrafficWorks OS to deliver a full range of application switching solutions cusotmizable to the customer environment.

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