Which two statements are correct about MAC and IP addresses during data transmission if NAT is not involved? (Choose two.)

When considering data transmission without NAT (Network Address Translation), the correct statements about MAC and IP addresses are:

1. Destination and source MAC addresses have local significance and change every time a frame goes from one LAN to another. MAC addresses are used for local area network (LAN) segment delivery and are changed at each hop where the frame is forwarded by routers, as the router will replace the source MAC address with its own and the destination MAC address with that of the next hop.
2. Destination IP addresses in a packet header remain constant along the entire path to a target host. When a packet is sent from a source to a destination, the source and destination IP addresses in the packet header remain the same from the source to the destination if NAT is not being used. Routers use these IP addresses to make forwarding decisions and do not alter them when routing.

The other statements are incorrect:

• Destination MAC addresses will never change in a frame that goes across seven routers. This statement is incorrect because, as mentioned, the destination MAC address changes at each hop.
• A packet that has crossed four routers has changed the destination IP address four times. This statement is false because, without NAT, the destination IP address remains the same across all routers.
• Every time a frame is encapsulated with a new destination MAC address, a new destination IP address is needed. This is not correct; the destination IP address does not change even though the MAC address changes as the frame moves through different segments of the network.