Flashcards #5
Which neighbor state indicated that a BGP Router is attempting to establish a TCP connection?
Active
What are the three BGP neighbor states?
Idle - Will stay in Idle state until a remote peer is configured and send a TCP connection Request.
Active - Device attempts to establish a TCP session with the remote peer by using a RCP ConnectTety timer. If fails, goes back to Idle
Established -
What does a router in the DROTHER state mean?
OSPF. Can only establish adjacencies with the DR Router and the Backup Designated Router (with only two other routers). It is neither a DR or BDR
What is SNR?
Signal to Noise Ratio. Refers to the difference between a received signal and the surrounding noise, which is also referred to as the noise floor.
The greater the seperation between signal and noise, the higher the likelihood that wireless clients will not experience packet loss due to signal interference. If SNR too low, the wireless client might no tbe able to distinguish some parts of the signal from the surrounding noise, which may result in packet loss.
What could cause the error message %STP-2-DISPUTE_DETECTED?
When a unidirectional link failure exists between two switches.
SWITCH A —-> X SWITCH B
What is the default transport protocol that syslog uses?
UDP
HSRP states?
- Init
- Learn
- Listen
- Speak
- Standby
- Active
What are the 3 states of HSRP?
- Active
- Standby
- Listen
The active router is the router in the group with the HIGHEST HSRP priority value, and the stanby router is the router with the second-highest HSRP priority vlaue. Other routers int he HSRO group are in the listen state. If the active router fails, the stanb router will assume the active router role and a new stanbu router will be elected.
What does HTTP status code 501 mean?
Indicates that the requested resource functionality is not implemented on the server.
For example a HTTP server htat does not support POST or PUT functions will retrn an HTTP status coed of 501 if a client request those functions.
Why is IS-IS preferred over OSPF when considering an underlay IGP for a SD WAN deployment?
IS-IS uses fewer CPU resources than OSPF uses.
IS-IS supports more Network layer protocols than OSPF supports.
What is RPF?
Reverse Path Forwarding ensures that multicast traffic always glows downstream from the mulitcast receivers.
What is the purpose of a Hold Down Timer?
Are used to specifiy hte amount of time to suppress information regarding a better path the a router.
When a router receives a routingh update stating that a route is unreachable, the router wais a specified amount of time before accepting routes advertised by other sources.
How many bytes does the GRE tunnel key add to the header of encapsulated packets?
4.
GRE is a Cisco-propriety rotocl that can tinnel traffic from one network to another without erquiring that the transport network support the network protocls in use at the tunnel source or tunnel destination.
Which two authentication methods were invented by Cisco?
LEAP
EAP-FAST
What is NAT-PT?
Used between communication of IPv4 only hosts and IPv6 only hosts which enables communication between these by translating IPv4 packets to IPv6 packets and IPv6 packets to IPv4.
To enable NAT-PT (Network Address Translation - Protocol Translation) need to :
- Assign a global NAT-PT prefic
- Enable NAT-PT on the incoming and outgoing interfaces
- Create IPv4 to IPv6 and IPv6 to IPv4 address mappings
Prefix length is always going to be 96. (All other prefix lengths are invalid)
What command is used to limit the captured traffic to only traffic from vlans 4,10,11,12, and 15?
monitor session 1 filter vlan 4, 10 -12, 15
When issueing the weight command to make BGP prefer one route over another, would we set the weight at maximum or minimum?
Maximum. 65535.
a path with a weight of 65535 will be preferred over a path with a weight of 0.
STP, Higher or Lower preferred?
Lower port priorites are preferred over higher.
Therefore a port with a port priority value of 0 would be preferred over other ports.
What must match for two routers running OSPFv3 to establish a neighbor adjacency?
- Area IDs
* Instance IDs
What is appended to a VPNv4 BGP route to indicate membership in an RFC 4364 MPLS VPN?
An RT (Route Target)
https://tools.ietf.org/html/rfc4364
What HTTP Status Code indicates theat the requested resource functionality is not implemented on the server?
501
What doesnt Cisco Mobility Express Support?
Layer 3 Roaming
What device operates with a 100% duty cycle?
An Analog video camera.
These can acuse interference to 802.11g networks. A duty cycle is the % of time that an entity is in an active state during a specified amount of time. Devices with high duty cycles have the potential to cause significantly more interfernce than devices with low duty cycles.
High duty cycles devices are as follows:
- Radar systems
- Rogue Access Points
- Analog Video systems
