Please note that if a device with proxy arp enabled exists on the next-hop interface, and uses the static route for default-route expressed as format, 1), the ARP entry for the packet destination will be created sequentially and the ARP table size may increase unexpectedly.
When using broadcast media as the next-hop interface, you can avoid such problems by configuring using format 2).
2. Static route with only the next-hop address specified
Format 3) is called recursive static. As a basic rule, this format is installed to the routing table when the path to next-hop has been derived. We frequently receive inquiries that the static remains in the routing table even when the interface is down. In most such cases, the static in this format is used, and the route to next-hop address is available.
The reason why we say "as a basic rule" here is because there are some exceptions.Here are some examples:
In this example, the route for the static next-hop 10.1.1.1 exists separately as 10.1.1.1/32.The next-hop path that 10.1.1.1/32 will use has been derived via connected. Therefore, it will not be a circular reference and both static routes have been installed onto the routing table.
If the connected Ethernet1/0 is down, all static routes will disappear.
2-2. Route for next-hop is another static route which includes own route (it has shorter mask)