What is the ruling on boasting about lineage?

Boasting about ancestry is forbidden and is a characteristic of the Age of Ignorance (Jahiliyyah). Islam has prohibited it. Allah, the Almighty, says: (O YOU WHO HAVE BELIEVED, LET NOT A PEOPLE RIDICULE ANOTHER PEOPLE; PERHAPS THEY MAY BE BETTER THAN THEM) and (O MANKIND, INDEED WE HAVE CREATED YOU FROM MALE AND FEMALE AND MADE YOU PEOPLES AND TRIBES THAT YOU MAY KNOW ONE ANOTHER. INDEED, THE MOST NOBLE OF YOU IN THE SIGHT OF ALLAH IS THE MOST RIGHTEOUS OF YOU). The Prophet (peace be upon him) condemned slandering lineage and boasting about one's deeds and status. However, learning about lineages to know and maintain ties of kinship is permissible and religiously encouraged, due to the Prophet’s (peace be upon him) saying: "Learn about your lineages that you may maintain ties of kinship through them."