Visa policy of Sudan
Visitors to Sudan must obtain a visa from one of the Sudanese diplomatic missions unless they come from one of the visa exempt countries.
Visa exemption
Citizens of the following 6 countries can visit Sudan without a visa:
Holders of diplomatic or official/service/special passports issued to nationals of Algeria, Benin, Brazil, Burkina Faso, Central African Republic, Chad, Congo, Djibouti, Egypt, Eritrea, Ethiopia, Gambia, Guinea, Iran, Libya, Mali, Morocco, Niger, Nigeria, Senegal, Togo and Tunisia do not require a visa for Sudan.[1]
Nationals of 
Saudi Arabia do not require a visa for business visits.
Visa on arrival
Citizens of the following 4 countries can obtain a visa for Sudan on arrival:
1 - provided arriving directly from the country of citizenship.
Holders of diplomatic or service passports of China and holders of diplomatic passports of Algeria can obtain a visa for Sudan on arrival.
People of Sudanese origin can obtain visa on arrival regardless of their current nationality.
Israel
Entry and transit is refused to 
Israeli citizens, even if not leaving the aircraft and proceeding by the same flight.[2]
Admission is also refused to holders of passports or travel documents containing a visa or entry stamp issued by Israel.[3]