get bypassed during the attacks. Routers Similar to switches, routers have some rate-limiting and ACL capability. They, too, are manually set. Most routers can be easily overwhelmed under a DoS attack.Nokia SR-OS using FP4/FP5 processors offers DDoS protection. Nokia SR-OS also uses big data analytics based Nokia Deepfield Defender for DDoS protection.Cisco IOS has optional features that can reduce the impact of flooding. Switches Most switches have some rate-limiting and ACL capability. Some switches provide automatic and/or system-wide rate limiting, traffic shaping, delayed binding (TCP splicing), deep packet inspection and Bogon filtering (bogus IP filtering) to detect and remediate DoS attacks through automatic rate filtering and WAN Link failover and balancing. These schemes will work as long as the DoS attacks can be prevented by using them. For example, SYN flood can be prevented using delayed binding or TCP splicing. Similarly, content-based DoS may be prevented using deep packet inspection. Attacks originating from dark addresses or going to dark addresses can be prevented using bogon filtering. Automatic rate filtering can work as long as set rate thresholds have been set correctly. Wan-link failover will work as long as both links have DoS/DDoS prevention mechanism. Blocking vulnerable ports For example, in an SSDP reflection attack; the key mitigation is to block incoming UDP traffic on port 1900 at the firewall. Unintentional denial-of-service An unintentional denial-of-service can occur when a system ends up denied, not due to a deliberate attack by a single individual or group of individuals, but simply due to a sudden enormous spike in popularity. This can happen when an extremely popular website posts a prominent link to a second, less well-prepared site, for example, as part of a news story. The result is that a significant proportion of the primary site's regular userspotentially hundreds of thousands of peopleclick that link in the space of a few hours, having the same effect on the target website as a DDoS attack. A VIPDoS is the same, but specifically when the link was posted by a celebrity. When Michael Jackson died in 2009, websites such as Google and Twitter slowed down or even crashed. Many sites' servers thought the requests were from a virus or spyware trying to cause a denial-of-service attack, warning users that their queries looked like "automated requests from a computer virus or spyware application". News sites and link sitessites whose primary function is to provide links to