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.
Leg cramps Leg cramps, when a muscle in the leg tightens and doesn't loosen up, causes pain and bulging in the leg. Low potassium (hypokalemia) If the level of potassium in your blood drops below normal, it may cause low energy, leg cramps, and more. Muscle strain Muscle strain occurs when muscles are stressed, overworked, or injured due to physical activity or labor.