Since resetting a router means all the settings are flushed out and restored back to how they were right out of the box, you have to reenter all the customizations you've made like any wireless network settings (e.g. SSID and wireless password), DNS server settings, port forwarding options, etc.
Ebe ọ bụ na ịtọgharị onye na-eme ihe ntanetịpụtara na-eme ka ntọala niile gbanwee ma weghachite ha si na igbe ahụ, ị ga-akpọghachi ihe niile ị mepụtara dịka ntọala netwọk ọ bụla (eg SSID na paswọọdụ wireless), DNS server Ntọala, nhazi nhọrọ ụgbọ mmiri, wdg.