Routers and routing protocols
In this section, we will examine routers, routing principles, and additional mechanisms such as Access Control Lists (ACLs), layer 3 switching, HSRP/VRRP, Network Address Translation (NAT), and more. In Chapter 12, Attacking Routing Protocols, we will take a deep dive into the details of routing protocols, their vulnerabilities, potential attacks, and how to defend against them.
Routing operations
Routing is the process of moving packets from end to end through the network. As you can see in Figure 2.20, the PC on the left, 10.1.1.20/24
, sends the packet to its default gateway, R1, with an IP address of 10.1.1.1/24
. R1 forwards the packet to the next router, R7, which then forwards it to R3, then to R4, and then to the destination of 20.1.1.20
:
There are several important issues regarding routing:
- The device that sends the packet looks at the destination address, and since this address is...