Quick Notes - CABLING TECHNOLOGY
What is a straight-through cable, and when would you use it?
A straight-through cable is the same at both ends. A straight-through cable uses pins 1, 2, 3, and 6. The send and receive wires are not crossed. You should use a straight-through cable when connecting dissimilar devices. Examples include connecting PCs to switches or hubs or a router to a switch or a hub.
What is a crossover cable, and when would you use it?
A crossover cable is a cable that has the send and receive wires crossed at one of the ends. On a Category 5 cable, the 1 and 3 wires and the 2 and 6 wires are switched on one of the cable's ends. You should use a crossover cable when connecting similar devices, such as connecting a router to a router, a switch to a switch or hub, a hub to a hub, or a PC to a PC.
Important tip -- Router (think of it as a PC) to PC via 10BaseT (NIC) uses a "crossover cable". (contradicts the rule)
How do you set up a console session to a Cisco device?
To set up a console session to a Cisco device, you connect a rollover cable to the console port on the Cisco device. You then connect the other end to your PC and configure a terminal emulation application to the following com settings: 9600 bps, 8 data bits, no parity, 1 stop bit, and no flow control.
What is the maximum cable length for each of the following?
The maximum cable lengths are as follows:
10Base2 (thinnet) 185 meters
10Base5 (thicknet) 500 meters
10BaseT 100 meters
10BaseFL 2000 meters (400 meters in a shared environment and 2000 meters in a point-to-point environment)
100BaseT 100 meters
What does Base stand for in 10BaseT and 100BaseT?
Base in 10BaseT and 100BaseT stands for baseband. Baseband is a network technology in which only one carrier frequency (signal) is used.
What is the difference between baseband and broadband?
Baseband is a network technology in which only one carrier frequency is used (such as Ethernet). Broadband is a network technology in which several independent channels are multiplexed into one cable (for example, a T1 line).
Quick Notes - ACCESS LISTS
Besides named access lists, what are the two types of IP access lists?
The two types of IP access lists are standard and extended.
What criteria do standard IP access lists use to filter packets?
Standard IP access lists filter packets by the source address. This results in the packet's being permitted or denied for the entire protocol suite based on the source network IP address.
What criteria do extended IP access lists use to filter packets?
Extended IP access lists filter packets by source address, destination address, protocols, and port numbers.
In what two ways can IP access lists be applied to an interface?
Access lists can be applied as inbound or outbound access lists. Inbound access lists process packets as they enter a router's interface and before they are routed. Outbound access lists process packets as they exit a router's interface and after they are routed.
How many access lists can be applied to an interface on a Cisco router?
Only one access list per protocol, per direction, per interface can be applied on a Cisco router. Multiple access lists are permitted per interface, but they must be for a different protocol.
How are access lists processed?
Access lists are processed in sequential, logical order, evaluating packets from the top down, one statement at a time. As soon as a match is made, the permit or deny option is applied, and the packet is not applied to any more access list statements. Because of this, the order of the statements within any access list is significant.