Sure, all TXIDs are solely calculated from non-witness knowledge. Whereas many nodes have an entire copy of the blockchain, which does include all transactions, most nodes would not have a full transaction index.
Nodes will promote unconfirmed transactions. These are then obtainable to be shared upon a
getdata tx request which can be responded to with a
If the transaction is already confirmed, the peer ought to know by which block the transaction was included (from the context by which it heard concerning the transaction within the first place), and would both request the entire block, or a Merkle department within the type of a
You possibly can learn extra concerning the P2P messages for instance right here: https://developer.bitcoin.org/reference/p2p_networking.html