Point-to-Point Protocol - Introduction

The Point-to-Point Protocol (PPP) originally emerged as an encapsulation protocol for transporting IP traffic over point-to-point links. PPP also established a standard for the assignment and management of IP addresses, asynchronous (start/stop) and bit-oriented synchronous encapsulation, network protocol multiplexing, link configuration, link quality testing, error detection, and option negotiation for such capabilities as network layer address negotiation and data-compression negotiation. PPP supports these functions by providing an extensible Link Control Protocol (LCP) and a family of Network Control Protocols (NCPs) to negotiate optional configuration parameters and facilities. In addition to IP, PPP supports other protocols, including Novell's Internetwork Packet Exchange (IPX) and DECnet.

What Is Routing?

Routing is the act of moving information across an internetwork from a source to a destination. Along the way, at least one intermediate node typically is encountered. Routing is often contrasted with bridging, which might seem to accomplish precisely the same thing to the casual observer. The primary difference between the two is that bridging occurs at Layer 2 (the link layer) of the OSI reference model, whereas routing occurs at Layer 3 (the network layer). This distinction provides routing and bridging with different information to use in the process of moving information from source to destination, so the two functions accomplish their tasks in different ways.
The topic of routing has been covered in computer science literature for more than two decades, but routing achieved commercial popularity as late as the mid-1980s. The primary reason for this time lag is that networks in the 1970s were simple, homogeneous environments. Only relatively recently has large-scale internetworking become popular.

CCNA Discovery 4 - Module 8 Exam Answers V.4 #6-10

6. Which flag is set by a Frame Relay switch to inform the receiving station that congestion was experienced?
• BECN
• DE
• FECN
• FCS

7. Refer to the exhibit. The complete configuration of a Frame Relay interface on the Chicago router is shown. How does the Chicago router know which DLCI is mapped to the IP address of the remote router?
• DE
• CIR
• FECN
• Inverse ARP

8. What statement correctly defines the purpose of the split horizon rule?
• marks the route unreachable in a routing update that is sent to other routers
• prevents routers from advertising a network through the interface from which the update came
• prevents routers from accepting higher cost routes to networks previously marked as inaccessible before the timer expires
• limits the number of hops a packet can traverse through the network before it should be discarded

9. Which PVC status suggests that the router recognizes the DLCI configured on its interface as being present on the Frame Relay switch, but the PVC associated with the DLCI is not capable of end-to-end communication?
• active
• deleted
• inactive
• idle

10. Refer to the exhibit. Which router command is used to associate a Layer 2 address with the corresponding Layer 3 address?
• Miller(config-if)#frame-relay map ip 172.16.150.1 110
• Miller(config-if)#frame-relay map ip 172.16.150.1 112
• Miller(config-if)#frame-relay map ip 172.16.150.2 110
• Miller(config-if)#frame-relay map ip 172.16.150.2 112

CCNA Discovery 3 - FINAL Exam Answers V.4 #16-20

16. What two statements are true regarding EIGRP tables? (Choose two.)
• A feasible successor route can be found in the topology table.
• A successor route can only be found in the routing table.
• The topology table shows whether a route is in the passive or active state.
• The routing table shows the amount of time elapsed since a router adjacency was formed.
• The neighbor table shows all adjacent Cisco devices.
• Administrative distance is shown as a column in the neighbor table.

17.

Refer to the exhibit. Assuming that all three routers are configured with the EIGRP routing protocol and sharing information, what information can be gathered from the show command output?
• Router B has EIGRP adjacencies with both router A and C.
• Router B has a fully converged topology table.
• Router B has not formed an adjacency with router A.
• Router B has not formed an adjacency with router C.

18. Which three statements are true about RSTP? (Choose three.)
• RSTP can fall back to STP to provide support for legacy equipment.
• RSTP and STP have the same number of port states.
• Like PortFast and UplinkFast, RSTP is a proprietary protocol.
• RSTP takes up to 50 seconds to converge.
• RSTP requires a point-to-point, full-duplex connection.
• RSTP views all ports that are not discarding as part of an active topology.

19.

Refer to the exhibit. A network support technician has been asked to set an IP address on one of the FastEthernet interfaces on a new router. What is causing the interface to reject the address?
• The IP address is already in use.
• The technician is using a network address.
• The technician is using the wrong subnet mask for /26
• The technician must enable VLSM on the interface.

20.

Refer to the exhibit. A network administrator enters the command ip route 10.10.4.16 255.255.255.248 s0/0/1 into the router. What will be the result of this configuration?
• A static route pointing to 10.10.4.16/29 is placed into the routing table.
• A static route to 10.10.4.16/29 is placed into the routing table if interface FastEthernet0/1 goes down.
• A static route pointing to 10.10.4.16/29 is only placed into the routing table if the route to 10.10.4.0 is removed.
• A static route is not placed into the routing table because a RIP route that includes the destination network already exists.

CCNA EXAM

The Cisco Certified Network Associate (CCNA®) Certification is a sought after qualification for many people working in the Networking arena. It is a certification that validates you to do a number of things. Namely, you will be able to install and configure a medium sized network. You will also be able to operate as well as troubleshoot the network.

These networks are usually routed and switch type network infrastructures. As part of your CCNA skills you will be able to implement and verify network connections to remote sites in a Wide Area Network (WAN). The curriculum of the CCNA will have you studying the possible threats to security and how to prevent such attacks.

Further to your studies touch on the concepts and terminology of wireless networking. You will get a grounding in popular protocols in use today such as Internet Protocol (IP), Enhanced Interior Gateway Routing Protocol (EIGRP), Serial Line Interface Protocol Frame Relay, Routing Information Protocol Version 2
(RIPv2),VLANs, Ethernet, access control lists (ACLs).

The CCNA Associate paths including CCNA, CCENT, CCNA Security, CCNA Voice and CCNA Wireless.

The CCNA 640-802 in particular has a number of specific exam topics which are:

Describe how a network works so you can for example Interpret network diagrams and differentiate between LAN/WAN operation and features. Be able to use the OSI and TCP/IP
models and their associated protocols to explain how data flows in a network among other
things.

In your training you will come across how to configure, verify and troubleshoot a switch with

VLANs and interswitch communications which will involve verifying network status and switch
operation using basic utilities (including: ping, traceroute, telnet, SSH, arp, ipconfig),
SHOW & DEBUG commands.

As you progress through your training in the 640-802 CCNA material you will experience how to implement an IP addressing scheme and IP Services to meet network requirements in a medium-size Enterprise branch office network. This will certainly help you to become much more proficient at describing IPv6 addresses and be able to undertake the Calculation and application of an addressing scheme including VLSM IP addressing design to a network.

Hands-on activity will have you configuring, verifying, and troubleshooting basic router operation and routing on Cisco devices such as OSPF and EIGRP. Not forgetting RIPv2 protocol as well as introduction to the SDM workings.

Explanation and selecting the appropriate administrative tasks required for a WLAN is an important activity for the budding CCNA Associate. You will learn about wireless technology such as SSID, BSS and ESS as well as standards such as IEEE WI-FI Alliance, ITU/FCC.

Linux home networking - syslog Configuration and Cisco Devices

Cisco Routers

By default Cisco routers send syslog messages to their logging server with a default facility of local7. Don't set the facility in this case, but do tell the router to timestamp the messages and make the messages have the source IP address of the loopback interface.

service timestamps log datetime localtime
no logging console
no logging monitor
logging 192.168.1.100

Catalyst CAT Switches running CATOS

By default Cisco switches also send syslog messages to their logging server with a default facility of local7. Don't change this facility either, therefore making routers and switches log to the same file.

set logging server enable
set logging server 192.168.1.100
set logging level all 5
set logging server severity 6

Cisco Local Director

Local Directors use the syslog output command to set their logging facility and severity. The value provided must be in the format FF.SS (facility.severity) using the numbering scheme in Table IV-1:

Table IV-1 Syslog Facility and Severity Numbering Scheme for Local Directors

Facility	FF Value		Severity	SS Value
local 0	16		System unusable	0
local 1	17		Immediate action required	1
local 2	18		Critical condition	2
local 3	19		Error conditions	3
local 4	20		Warning conditions	4
local 5	21		Normal but significant conditions	5
local 6	22		Informational messages	6
local 7	23		Debugging messages	7

This example uses facility local4 and the logging debugging messages from Table IV-1.

syslog output 20.7
no syslog console
syslog host 192.168.1.100

Cisco PIX Filewalls

PIX firewalls use the numbering scheme in Table IV.2 to determine their logging facilities.

Table IV-2 Syslog Facility and Severity Numbering Scheme for PIX Firewalls

Facility	Logging Facility Command Value
local 0	16
local 1	17
local 2	18
local 3	19
local 4	20
local 5	21
local 6	22
local 7	23

This configuration example assumes that the logging server is connected on the side of the "inside" protected interface. It sends log messages to facility local3 with a severity level of 5 (Notification) set by the logging trap command.

logging on
logging standby
logging timestamp
logging trap notifications
logging facility 19
logging host inside 192.168.1.100

Cisco CSS11000 (Arrowpoints)

The configuration for the Cisco CSS11000 load balancer series is more straightforward. You specify the facility with an intuitive number using the logging host command and set the severity with the logging subsystem command. This example shows the CSS11000 logging facility local6 and severity level 6 (Informational):

logging host 192.168.1.100 facility 6
set logging subsystem all info-6
logging commands enable

The Sample Cisco syslog.conf File

#
# All LOCAL3 messages (debug and above) go to the firewall file ciscofw
#
local3.debug /var/log/cisco/ciscofw

#
# All LOCAL4 messages  (debug and above) go to the Local Director file ciscold
#
local4.debug /var/log/cisco/ciscold

#
# All LOCAL6 messages  (debug and above) go to the CSS file ciscocss
#
local6.debug /var/log/cisco/ciscocss

#
# All LOCAL7 messages  (debug and above) go to the ciscoacl
# This includes ACL logs which are logged at severity debug
#
local7.debug /var/log/cisco/ciscoacl

#
# LOCAL7 messages  (notice and above) go to the ciscoinfo
# This excludes ACL logs which are logged at severity debug
#
local7.notice /var/log/cisco/ciscoinfo

CCNA Discovery 4 - Module 8 Exam Answers V.4 #1-5

1. Which mechanism is used to create a floating static route?
• administrative distance
• cost
• hop count
• passive interface

2. IPSec operates at which layer of the OSI model?
• application
• network
• datalink
• transport

3. Which is true regarding Frame Relay LMI?
• There are three LMI types standardized by ANSI, ITU-T, and Cisco.
• Routers at each end of a Frame Relay virtual circuit must always use the same LMI type.
• The LMI type must be manually configured.
• The only function of LMI is to verify the connection between the router and the Frame Relay switch.

4. Which statement identifies the IP address design for subinterfaces that are configured for a Frame Relay network?
• Multipoint configurations require the IP address of each subinterface on each router to be in its own subnet.
• Multipoint configurations require IP addresses for each subinterface on each router to be a part of the same subnet.
• Point-to-point configurations require IP addresses for each subinterface on each router to be a part of the same subnet.
• Point-to-point configurations do not require IP addresses on each subinterface on each router.
• Multipoint configurations do not require IP addresses on each subinterface on each router.

5. Which three algorithms can be used to encrypt user data in an IPSec VPN framework? (Choose three.)
• 3DES
• AES
• Diffie-Hellman
• DES
• ESP
• SHA

CCNA Discovery 4 - Module 8 Exam Answers V.4 #1-5

1. Which mechanism is used to create a floating static route?
• administrative distance
• cost
• hop count
• passive interface

2. IPSec operates at which layer of the OSI model?
• application
• network
• datalink
• transport

3. Which is true regarding Frame Relay LMI?
• There are three LMI types standardized by ANSI, ITU-T, and Cisco.
• Routers at each end of a Frame Relay virtual circuit must always use the same LMI type.
• The LMI type must be manually configured.
• The only function of LMI is to verify the connection between the router and the Frame Relay switch.

4. Which statement identifies the IP address design for subinterfaces that are configured for a Frame Relay network?
• Multipoint configurations require the IP address of each subinterface on each router to be in its own subnet.
• Multipoint configurations require IP addresses for each subinterface on each router to be a part of the same subnet.
• Point-to-point configurations require IP addresses for each subinterface on each router to be a part of the same subnet.
• Point-to-point configurations do not require IP addresses on each subinterface on each router.
• Multipoint configurations do not require IP addresses on each subinterface on each router.

5. Which three algorithms can be used to encrypt user data in an IPSec VPN framework? (Choose three.)
• 3DES
• AES
• Diffie-Hellman
• DES
• ESP
• SHA