Chapter 4 Flashcards
What two mechanisms can be used to monitor and manage the amount of traffic?
Shaping and policing
What two mechanisms assign packets to queues and determine how they are forwarded?
Classification and marking
What is tail drop?
A congestion avoidance mechanism that drops further incoming packets when the queue is full
What is Random Early Detection? (RED)
A congestion avoidance mechanism that drops packets before congestion occurs, the rate at which it drops packets depends on how much of the queue has filled
What congestion avoidance methods tacks packet priority into account when dropping packets?
Weighted Random Early Detection (WRED)
What QoS level prioritizes voice traffic?
Platinum
What does traffic shaping do?
Queues excess traffic
What modifies the QoS attributes of a packet?
Marking
What are two configurations that are required to enable SSH?
hostname
ip domain-name
crypto key
What serves as a password to protect access to MIB objects?
Community strings
What ports do syslog communicate on?
UDP 514, TCP 6514
What is syslog severity level 7?
Debugging
What is syslog severity level 6?
Information
What is syslog severity level 5?
Notifications
What is syslog severity level 4?
Warnings
What is syslog severity level 3?
Error
What is syslog severity level 2?
Critical
What is syslog severity level 1?
Alert
What is syslog severity level 0?
Emergency
How are incoming syslog server messages categorized?
Severity level, based on importance
What does the logging trap debug command do on a router?
Router will send all messages to the syslog server, you can specify a severity level and it will send that level and above
What might have happened if a notice level message was sent to a syslog server?
An interface line has changed status, a routing instance has flapped
How would you configure a syslog to receive error conditions?
logging trap 3
What is a syslog facility?
A numeric value that represent the processes that can generate a log message
What port does FTP use?
TCP 20 & 21
What port does TFTP use?
UDP 69
What is the more secure protocol between FTP and TFTP and why?
FTP, because it has user authentication
What is true about the connections in FTP?
It uses two separate connections for control and data traffic
What is a use of TFTP?
To transfer configurations to and from network devices
What is a use of FTP?
Mostly used by remote users to upload and download files
What protocol uses block numbers to identify and mitigate data-transfer errors and offers anonymous user login ability?
TFTP
What port does DNS use?
TCP/UDP 53
What port does DHCP use?
UDP 67 & 68
What port does SNMP use?
UDP 161
What global configuration do all dynamic NAT and PAT begin with?
- Access list
- # ip nat inside source list n
What is the unique global command that configures NAT statically?
ip nat inside source static [private address] [public address]
What is the unique global command that configures NAT dynamically?
- ip nat pool n [start-end ip] netmask [a.b.c.d]
- # ip nat…pool n
What is the unique global command that configures PAT?
ip nat… interface [outside if] overload
What is the command to verify NAT configuration?
show ip nat translation
What must be configured on an NTP server?
Time zone
ntp server-pool
ntp master
What must be configured on an NTP client?
Time zone
ntp server
What protocol does NTP use?
UDP
What is the configuration needed to enable SSH?
(config)#ip domain-name (name)
(config)#username (name) password (pw)
(config)#crypto key generate rsa
What is the configuration needed to enable only SSH access to a device?
(config)#line vty 0 15
(config-line)#login local
(config-line)#transport input ssh
How do you configure a DHCP client?
ip address dhcp
What configuration is needed to configure a DHCP relay agent?
ip helper-address (dhcp server ip address)
Why would a DHCP relay agent be configured?
When clients and a DHCP server are not on the same physical network, a DHCP relay agent is needed to forward DHCP requests and replices
What router gets configured as a helper? (location)
The one closest to the client
What command can be used to verify DHCP relay agent address configuration?
show ip interface
Which command could be used on a DHCP server to look at addresses assigned?
show ip dhcp binding
What does a DHCP server do when two hosts are using the same IP address?
The address is removed from the pool until until an administrator resolves the conflict
What is the highest security network device monitoring protocol?
SNMPv3
In SNMP, what do community strings do?
They’re passwords to protect access to MIB objects
What protocol allows you to back up multiple network configurations globally using the copy function?
SNMP
What does an SNMP agent do?
Responds to requests from the NMS and sends information about a device (MIB)
In SNMP operations, what are MIBs?
A collection of variables that can be monitored
What security was added in SNMPv3?
Authentication
What is a GetBulkRequest in SNMPv2?
Allows a management station to retrieve a large amount of data in one request
In SNMP, what is the difference between trap and inform?
Trap messages are not reliable, they’re sent and forgotten
In SNMP, what is a similarity between trap and inform?
Both use UDP, and both notify the manager of events
What commands are needed to configure a router to provide IP addresses to computers on the network?
ip dhcp pool [1]
network [address] [mask]
What does policing do to excess packets?
Drops and remarks
What is the purpose of traffic shaping?
Limit the bandwidth usage to prevent congestion
