East Blue Saga

Arrival of the Pirate Brothers
A short while before the storyline he met Portgas D. Ace, who thanked him for saving his little brother. Shanks responded by throwing a party to celebrate, as he didn't know Luffy had a brother.

Then a few years later after relaxing on an island after drinking too much, to the terror of a few of Shanks' weaker crew members, Dracule "Hawkeye" Mihawk pays Shanks a visit. The Shichibukai brought news that delighted the red-haired pirate: Luffy has gained a bounty of 30,000,000. Hearing Luffy had now come at last, Shanks threw another party despite being already unwell from his previous drinking session.[34]

Mihawk tracks down Shanks to inform him of Luffy's first bounty.