Coin addresses will be on the blockchain.
IP addresses would require an adversary with substantial resources.
That being said, do not use DEX for privacy. to make things private it is better to shield the funds after you get them, transfer them using shielded funds and then you can extract it and maintain privacy.
The only IP addresses that are in the data packets are the notary node IP addresses, which are quasi-public anyway.
However, a large-scale attacker could place routers one hop away from all notary nodes and reconstruct aggregate packet traffic.
However, the counterparty is trading against a pubkey and not an IP address.
Basically, only govt level resources would be able to correlate IP address with pubkey, or I guess an evil notary node could get a partial picture.
Again, do not rely on DEX for privacy, but the iguana DEX provides a lot more privacy than the typical p2p trading as it is using pubkeys for the trading address.