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.
Diabetes or other conditions that disrupt your metabolism can also cause muscle cramps. Night leg cramps are sometimes confused with restless legs syndrome (RLS). With RLS, you feel throbbing, pulling or other unpleasant sensations in your legs and have an uncontrollable urge to move your lower limbs. These symptoms primarily occur at night or when at rest.