Karteikarten
Cisco WAN Final
Karten in diesem Stapel (59)
- 1Ch 8 Physical layer Show commandsShow IP int brief
- 2Interpret show int br resultsUp - physical and config ok
Down - not configured
Admin down - no shut required - 3Connectivity Serial intShow controller s0/0/0
- 4Switch interfaceshow int f0/1
- 5Data link layer show commandSh mac addr table
- 6sh mac addr table resultsvlan mac addr port
10 1111 f0/1
1 2222 F0/2
10 3333 f0/3
20 3333 f0/4
Vlan 10 and 20 are trunking on same mac addr - 7Switch sh cdp neighborshows
hostname of neighbor - 8CDPDefault system for Cisco
- 9Network Layer Show commnadssh ip int brief
sh protocol
sh ip route
sh ip eigrp nieghbours
sh ip ospf neighbours
ping
traceroute - 10Transport Layer issuesmore than likely issue with ACL or NAT
- 11SLASource Level Agreement
Load balancing
set various triggers for alerts to admin
overnight tracking for connection issues and warnings. - 12SLA commandsip sla 1
icmp-echo xxxx
frequencey 300
ip sla schedule 1 start-frame now lifetime forever
frequency is the time in seconds for a 5 minute period of time. - 13SLA Statisticsshow ip sla statistics
# of successes
# of failures
Can be set to - trap or logging info - 14QoSVideo and voice set to UDP
sensitive to jitter - 15Jittervariation in delay
- 16Queuing StrategiesFIFO - default
WFQ - Weighted fair queuing. Cisco auto config
CBWGQ - Class based WFQ
LLQ - Low latency queuing. Voice priority first. - 17FIFODefault
First in First out - 18WFQWeighted Fair Queuing
Marks frames for priority
AF - Assured Forwarding
Not able to tunnel or encrypt - 19WFQ MarkingLayer 2
marks vlan tag
Layer 3
marks service field / differentiated service field
IPV6
Traffic type field - 20MechanismsBest Effort
Integrated Services
Differentiated Services - 21Best EffortNo gaurantee of delivery
All data treated the same.
First in First out - 22Integrated ServicesEdge router reserves resources for required bandwidth
If it cannot gaurantee resources it does not send. - 23Differentiated ServicesScalable
Cost-effective
Almost gauranteed
Divides traffic into classes - 24Implementation TechniquesMarking packets to determine priority
Congestion avoidance - WRED
Queuing Traffic - 25Trust boundariesMarked as close to the source as possible
- 26Congestion AvoidanceDepending on Queue threshold packets are:
Below - no drops
Close - small amount dropped
Passed - dropped - 27Shapingdelay of packet transmissions until threshold is not at capacity and then sent.
- 28PolicingAny packets that exceed the threshold are dropped.
- 29DHCP SnoopingOn router
ip dhcp snooping
ip dhcp snooping vlan 10,20
On switch
int f0/1
ip dhcp snooping trust - 30TXTransmit
- 31RXReturn
- 32Monitor traffic to and from routermonitor session 1 source f0/1
monitor session 1 destintation f0/10
Destination device is receive only and cannot send any data out. - 33SyslogLogging 1.1.1.1
or
Logging host 1.1.1.1
1.1.1.1 is destination to send data to. - 34TrapCondition that is configured to send a message if some specific issue happens.
Automated warning. - 35WAN operates primarily on the:OSI Physical and data-link layers
- 36WAN topology that allows all sites to communicate with all remote sites.Full Mesh
- 37Possible cause for status: S0/0/0 is up, line protocol is downEncapsulation at either end is not consistent.
- 38Show command display all IPV4 int and masks?Show protocols
- 39Not supported by PPPData encryption
- 40PPP protocol that negotiates authentcationLCP
- 41Command to display LCP and NCP statesShow int s0/0/0
- 42Extended ACL number ranges100 to 199
2000 to 2699 - 43Permit icmp any any dn-na Permit icmp any any dn-nsEquivalent to ipv4 ARP
- 44CDPCisco Discovery Protocol
- 45CDP IssuesBroadcasts are sent unencrypted and unauthorized.
Disable CDP on edge router ports that connect to untrusted devices. - 46How to prevent MAC Table FloodingConfigure Port Security on switch
- 47SNMP V3 Simple Network Management ProtocolAuthenticates and encrypts packets
- 48SNMP V1 V2 Simple Network Management ProtocolVisible password
Not secure
Vulnerable to man in middle attack - 49Port MirroringAllows a switch t send eternet frames from a specified port to a destination port that has a packet analyzer (Wireshark) connected to it.
- 50SPANSwitch Port Analyzer
sends copies of frames entering a port out another port on the same switch - 51Remote SPANAllows source and destination ports to be in different switches to mirror frames to capture by Wireshark.
- 52Trouble shooting proceduresGather information
Determine ownership
Narrow the scope
Gather Symptoms from devices
Document symptoms - 53ACL entry equivalentsdeny any host 1.1.1.1
deny any host 1.1.1.1 0.0.0.0
permit icmp any any
permit icmp any 0.0.0.0 255.255.255.255 - 54What device is considered a supplicant during the 802.1X authentication processthe client that is requesting authentication
- 55Which SNMP version uses weak community string-based access control and supports bulk retrievalSNMPv2c
- 56Which protocol defines port-based authentication to restrict unauthorized hosts from connecting to the LAN through publicly accessible switch ports?802.1X
- 57What are three techniques for mitigating VLAN attacks?Mitigating a VLAN attack can be done by: disabling Dynamic Trunking Protocol (DTP), manually setting ports to trunking mode, and by setting the native VLAN of trunk links to VLANs not in use.
- 58Describe SNMP operationsAn SNMP agent that resides on a managed device collects and stores information about the device and its operation. This information is stored by the agent locally in the MIB. An NMS periodically polls the SNMP agents that are residing on managed devices by using the get request to query the devices for data.
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