350-021 - CCIE Service Provider Cable Recertification Exam
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Which addresses below would be valid IP addresses of hosts on the Internet? (multiple answer)
In BGP, why should a Route Reflector be used?
To allow the router to reflect updates from one Internal BGP speaker to another without the need to be fully meshed
HFC cable television return path networks are aligned to provide: (multiple answer)
Unity gain with a fixed input level and varying output levels adjusted by the selection of a fixed value attenuator and equalizer at the output stage in each of the return amplifiers in the network
Cable modems the ability to power range comfortably within their output power dynamic range
The main purpose of tags within cisco network registrar is to:
Associate clients, client classes, and scopes.
A router is set to boot from flash, but cannot find boot commands in the configuration. Also, valid files do not exist in the default flash device. The router will:
Try to boot from the network, then boot from ROM as a backup
What would be the proper recommendation to an MSO's marketing department for offering data services?
Tiered data rates with asymmetrical speeds
The purpose of Administrative Distance, as used by Cisco routers, is:
To choose between routes from different routing protocols when receiving updates for the same network
An old head-end hub site is inherited that services 30,000 HHP and the DOCSIS cable modem services must be made operational. There are 15 fiber nodes serving the area combined 4:1. The HFC is a 2-way 550 MHz system but is old and leakage has been found measuring 150 uV/m in multiple locations. Extensive ingress has also been found in the return path on the analyzer on each return leg. Given the above conditions it would be best to design the network to use:
A modulation profile that utilizes all QPSK MAC messages for maximum noise immunity
To eliminate the need for adjacent routers on broadcast networks to form n(n-1)/2 adjacencies, IS-IS defines a pseudonode or Designated Intermediate System, DIS. All router on the broadcast medium form an adjacency with the DIS. The Backup DIS is called:
There is no concept of a backup DIS in IS-IS
The "Rec Power" field in the report produced by the "show cable modem" command includes an exclamation point (!) with the power level for a particular cable modem. This is an indication of:
The RF power level received at the CMTS line card upstream port and an indication that the cable modem has reached its maximum transmit power level
What statement is correct?
An IP header is 20 bytes long, or larger if options are used.
The two label distribution protocols that provide support for MPLS traffic engineering are:
RSVP and CR-LDP
The name of the DOCSIS config file to download will be offered to the cable modem in what DHCP field?
What is the nominal bandwidth of a DOCSIS 2.3 Mbps QPSK or 4.5 Mbps 16-QAM digitally modulated carrier?
What is an Inter Switch Link (ISL)?
A Cisco proprietary protocol for interconnecting multiple switches
In a Distance Vector protocol, "counting to infinity":
Sets an upper limit for hop count, so that routing loops can be broken if this limit is reached
In MPLS what is an LSP?
Label Switched Path
When configuring the smart-relay feature on the CMTS, what command allows you to populate the GIADDR with multiple secondary addresses?
cable dhcp-giaddr policy
Given a PAL HFC and 8 MHz channel lineup in the downstream, is it possible to utilize 6 MHz DOCSIS cable modems and signals on the network?
Yes, as long as the 6 MHz DOCSIS signal is within a valid 8 MHz channel
Entering the command "cable downstream if-output prbs" from the interface configuration prompt of the CLI will: (multiple answer)
Activate a downstream test signal which comprises a random data pattern modulated to look like a real data stream
Activate a pseudo random bit stream to be used for downstream spectrum analyzer test measurements
Interlaced fields are separated by:
Within OSPF, what functionality best defines the use of a 'stub' area?
It is a non-transit area that does not allow flooding of external networks and uses the default route to reach external networks.
What are the 4 bridge port states in a transparent bridging environment?
Listening, learning, blocking, forwarding
Running BPI, the "cable privacy mandatory" command:
Requires TEK & KEK establishment to online modems
When allocating address space within Cisco Network Registrar which statement is most correct?
Scopes should be set up to accurately reflect the subnets defined on the CMTS.
What command on the Ubr7246 can help find the possibility of a problem with ingress noise on cable x/y upstream? (multiple answer)
Show controller cable x/y upstream z
Show cable hop
Show int cable x/y upstream z
What establishes routing table precedence in a routing table?
The "show controllers cable x/y upstreram x" command does not detect impulse noise because:
Impulse is measured in microseconds and can't be detected.
When doing a show cable modem it is observed that a few modems are displaying the online(d) state. Users are complaining that they cannot surf the internet. One possible cause is that:
The modem has network access disabled in the config file.
During the modem boot process, how is the modem's power level set to communicate reliably with the headend ?
The modem is commanded by the CMTS to set power levels until the ranging is complete.
What is the recommended minimum carrier-to-noise ratio for downstream DOCSIS 64- and 256-QAM digitally modulated carriers?
What is the primary benefit of the "time-to-live" field in the IP header?
To reduce the impact of routing loops
What is true about the DLCI field in the Frame Relay header?
It generally has significance only between the local switch and the DTE device.
What Q.931 message cannot be received in response to sending a Q.931 SETUP message?
At what level relative to adjacent channel analog visual carrier levels should a DOCSIS 64- or 256-QAM digitally modulated carrier be operated?
6 dB to 10 dB lower
If there are two different headends with two different frequencies available sharing the same plant, what frequency will the two groups of cable modems, which are brand new, and have never been on-line, lock on?
They will lock on the first frequency they find.
What statement is correct regarding Virtual LANs (VLANs)?
It is permissible to bridge inside a VLAN and to route between VLANs.
What is the best IOS command for determining the channel bandwidth on an upstream port for slot 3?
show controller c 3/0 upstream
In order to avoid loops when sending routing updates, what is the correct technique to prevent a network from being forwarded on the same interface it is learned?
An incoming frame is received by a transparent bridge. If the destination address of the frame is not present in the database, the bridge will:
Send out the frame on all interfaces, except on the interface where the frame originate
Given an address of 10.1.1.1 with a subnet mask of 255.255.255.224, how many hosts can be addressed in this subnet?
What would be the best method for determining the cause of CPEs not getting provisioned an address?
Monitor the DHCP log file in CNR
The CLI command "show cable hop":(multiple answer)
Indicates corrected and uncorrected errors in the upstream.
Identifies the upstream receiver port that is supporting the modems causing customer service calls.
The correct search order for policies in Cisco Network Registrar is:
client embedded policyclient class named policyscope embedded policy
An ISP complains that users are changing their QOS profiles to faster rates than they are paying for. What command would provide the most effective solution?
no cable qos permission modem
You have been assigned to disable modem to modem communications to stop gaming on the recently built plant. What command would you implement?
no cable proxy arp
In Frame Relay, what devices resend packets that do not transmit correctly?
Network end stations
What Delimits the beginning and the end of the Frame Relay frame?
The optimal power level input for the upstream port on the CMTS is:
What is the recommended minimum carrier-to-noise ratio for upstream DOCSIS QPSK and 16-QAM digitally modulated carriers?