Routing and Switching

Routes

Routes are the backbone for most of the internet. It is a system of costs that help manage where traffic is supposed to go. Even for many in computers, the whole internet itself seems like a hard target. This is an illusion.

All it takes is for one computer to have a bad route or not be on the same page to mess up things. As one of my teachers put it, Pakistan made the mistake of blacklisting Youtube by black holing the domain. This works, but if you set the "cost" too low and your computers share that route with the whole world, suddenly the whole world tries to go through Pakistan to get to Youtube because the cost is low. Youtube is of course blacklisted in Pakistan.

• Syntax for routes on a Cisco Router: ip route [Incoming IP] [Incoming Subnet] [Outgoing Interface] [Next Hop Address] [Distance/Cost]

IP	MASK	OUTGOING	NEXT HOP	COST
Example	Example	Example
Example	Example	Example
Example	Example	Example
0.0.0.0	0.0.0.0	10.19.114.1	10.19.114.81	35
10.19.114.0	255.255.255.0	On-link	10.19.114.81	291
10.19.114.81	255.255.255.255	On-link	10.19.114.81	291
10.19.114.255	255.255.255.255	On-link	10.19.114.81	291
127.0.0.0	255.0.0.0	On-link	127.0.0.1	331
127.0.0.1	255.255.255.255	On-link	127.0.0.1	331
127.255.255.255	255.255.255.255	On-link	127.0.0.1	331
192.168.56.0	255.255.255.0	On-link	192.168.56.1	281
192.168.56.1	255.255.255.255	On-link	192.168.56.1	281
192.168.56.255	255.255.255.255	On-link	192.168.56.1	281