Sudan shares borders with many countries, but there are few crossing options. The security situation along the border with South Sudan is highly volatile, and though locals are taking boats down the White Nile between the two countries we've not heard of any travellers doing it. Most people consider an overland crossing between Sudan and South Sudan too dangerous to attempt. Libya is also risky, and while the Chadian border is technically open (but dangerous), there's no way a foreign traveller will be granted travel permits for Darfur.
It's not uncommon to see people riding bikes between Egypt and Sudan. They use the road from Aswan to Wadi Halfa.
Egypt The border between Wadi Halfa and Aswan is at Eshket and is open for all.
Eritrea The crossing between Kassala and Teseney is open, but the Eritrean side of the border area is closed to foreigners.
Ethiopia The border crossing is at Gallabat.
There are several daily (except Friday) bus services between Aswan (Egypt) and Wadi Halfa (Sudan). The whole trip takes about 12 hours. Border formalities are fairly straightforward. Sudanese visas are not issued at the border.
For Ethiopia, head to Gedaref, from where you'll find minibuses to the border town of Gallabat. Walk over the bridge to Metema (Ethiopia), where buses go direct to Gonder or, if you miss the bus, you can reach Gonder by changing vehicles in Shihedi. Note that you cannot get Ethiopian visas on the border.
The roads between Sudan and Egypt have been recently reopened. The road between Wadi Halfa and Aswan is the most convenient for overlanders.
Mazar Mahir, the brother of Midhat Mahir of Khartoum-based tour company Mashansharti, and Magdi Boshara have a good reputation for speeding people through the paperwork at the border – contact them by email before your arrival.
Hitching is never entirely safe in any country, and we don’t recommend it. Travellers who hitch should understand that they are taking a small but potentially serious risk. Still, if you want to enter Sudan from Egypt via the border town of Eshket, you can hitch a lift with one of the trucks that ply the route between Aswan and Wadi Halfa. This option is best avoided by women.