|  | 11.7 | ARP Tables
| 11.7.4 | ARP requests and ARP replies
ARP is used only on a local network. What would happen if a local router wanted to ask a non-local router to provide indirect routing (next-hop) services, but did not know the MAC address of the non-local router? When a router does not know the MAC address of the next-hop router, the source router (router that has the data to be sent on) issues an ARP request. A router that is connected to the same segment as the source router receives the ARP request. This router issues an ARP reply to the router that originated the ARP request. The reply contains the MAC address of the non-local router.