Ipswitch Dunne is a Named Enemy in DLC3 of Borderlands 3. He is also on the “Most Wanted” list. Ipswitch Dunne is located in The Blastplains on the Planet Gehenna. You will encounter him close to the “Fort Kickwater” Fast Travel Station.
You can farm Ipswitch Dunne for The Blanc as it is the dedicated loot source for this item. The Blanc has a 33% drop chance.