Router, ARP, Static route

General
1

1.Why router linkup automatically when its connected face to face?

  1. If centralized router power off can other routes communicate, if not then what is the alternatives solutions into static route.

  2. If we want to send ping packet from this topology Pcs A and B 2 pcs A and B are connected with one switch and switch connected with one router and
    router connected with second router and second router connected with one switch then switch connected with 2 pcs C and D. Or pcs C and D are connected with one that switch. Can we get arp pacet from pcs c nd D or not?

2

  1. When routers are connected face to face, we put them in same network and give no shutdown command thats why.

  2. If a centralized router powers off, other routers may still be able to communicate if alternative routes are available. This can be achieved through the use of redundant links or by implementing dynamic routing protocols that can dynamically reroute traffic in the network.

  3. In the scenario you described, where PCs A and B are connected to one switch, which is connected to a router, and that router is connected to a second router, which is then connected to another switch with PCs C and D, it is possible to receive ARP packets from PCs C and D. ARP (Address Resolution Protocol) is used to resolve IP addresses to MAC addresses on a local network segment, so as long as the PCs are on the same network segment, they should be able to exchange ARP packets.