The new Cisco IOS Firewall for Internet Protocol version 6 (IPv6) provides stateful inspection to both existing IPv4 and IPv6 traffic on a single interface for enhanced performance, along with better management of the IPv6 migration process.
Causes of Muscle contractions that are rare. The offical US government definition of a rare disease is one that affects 200,000 people or less. The following causes of Muscle contractions appear in the population at a rate of less than 200,000 people per year in the USA: 1  Alpers Syndrome-involuntary muscle contraction. 2  Fahr's Syndrome-athetosis. 3  Ramsay Hunt syndrome Type II-involuntary muscle contraction.
There are many medical conditions that can cause leg pain. 1  Fibromyalgia sufferers frequently experience restless leg syndrome and painful lower leg cramps.  Leg pain can also be associated with autoimmune disorders such as multiple sclerosis and rheumatoid arthritis. Thyroid disease can also cause pain in the legs.