Q1. CORRECT TEXT
You are a network engineer with ROUTE.com, a small IT company. They have recently merged two organizations and now need to merge their networks as shown in the topology exhibit. One network is using OSPF as its IGP and the other is using EIGRP as its IGP. R4 has been added to the existing OSPF network to provide the interconnect between the OSPF and EIGRP networks. Two links have been added that will provide redundancy.
The network requirements state that you must be able to ping and telnet from loopback 101 on R1 to the OPSF domain test address of 172.16.1.100. All traffic must use the shortest path that provides the greatest bandwidth. The redundant paths from the OSPF network to the EIGRP network must be available in case of a link failure. No static or default routing is allowed in either network.
A previous network engineer has started the merger implementation and has successfully assigned and verified all IP addressing and basic IGP routing. You have been tasked with completing the implementation and ensuring that the network requirements are met. You may not remove or change any of the configuration commands currently on any of the routers. You may add new commands or change default values.
Answer: First we need to find out 5 parameters (Bandwidth, Delay, Reliability, Load, MTU) of the s0/0/0 interface (the interface of R2 connected to R4) for redistribution:
R2#show interface s0/0/0
Write down these 5 parameters, notice that we have to divide the Delay by 10 because the metric unit is in tens of microsecond. For example, we get Bandwidth=1544 Kbit, Delay=20000 us, Reliability=255, Load=1, MTU=1500 bytes then we would redistribute as follows:
R2#config terminal
R2(config)# router ospf 1
R2(config-router)# redistribute eigrp 100 metric-type 1 subnets
R2(config-router)#exit
R2(config-router)#router eigrp 100
R2(config-router)#redistribute ospf 1 metric 1544 2000 255 1 1500
Note: In fact, these parameters are just used for reference and we can use other parameters with
no problem.
If the delay is 20000us then we need to divide it by 10, that is 20000 / 10 = 2000)
For R3 we use the show interface fa0/0 to get 5 parameters too
R3#show interface fa0/0
For example we get Bandwidth=10000 Kbit, Delay=1000 us, Reliability=255, Load=1, MTU=1500 bytes
R3#config terminal
R3(config)#router ospf 1
R3(config-router)#redistribute eigrp 100 metric-type 1 subnets
R3(config)#exit
R3(config-router)#router eigrp 100
R3(config-router)#redistribute ospf 1 metric 10000 100 255 1 1500
Finally you should try to “show ip route” to see the 172.16.100.1 network (the network behind R4)
in the routing table of R1 and make a ping from R1 to this network.
Note: If the link between R2 and R3 is FastEthernet link, we must put the command below under
EIGRP process to make traffic from R1 to go through R3 (R1 -> R2 -> R3 -> R4), which is better
than R1 -> R2 -> R4.
R2(config-router)# distance eigrp 90 105
This command sets the Administrative Distance of all EIGRP internal routes to 90 and all EIGRP external routes to 105, which is smaller than the Administrative Distance of OSPF (110) -> the link between R2 & R3 will be preferred to the serial link between R2 & R4. Note: The actual OPSF and EIGRP process numbers may change in the actual exam so be sure to use the actual correct values, but the overall solution is the same.
Q2. A network engineer is configuring a solution to allow failover of HSRP nodes during maintenance windows, as an alternative to powering down the active router and letting the network respond accordingly. Which action will allow for manual switching of HSRP nodes?
A. Track the up/down state of a loopback interface and shut down this interface during maintenance.
B. Adjust the HSRP priority without the use of preemption.
C. Disable and enable all active interfaces on the active HSRP node.
D. Enable HSRPv2 under global configuration, which allows for maintenance mode.
Answer: A
Explanation:
The standby track command allows you to specify another interface on the router for the
HSRP process to monitor in order to alter the HSRP priority for a given group. If the line protocol of the
specified interface goes down, the HSRP priority is reduced. This means that another HSRP router with
higher priority can become the active router if that router has standby preempt enabled. Loopback
interfaces can be tracked, so when this interface is shut down the HSRP priority for that router will be
lowered and the other HSRP router will then become the active one. Reference: http://www.cisco.com/c/
en/us/support/docs/ip/hot-standby-router-protocol- hsrp/13780-6.html
Q3. Which statement about the use of tunneling to migrate to IPv6 is true?
A. Tunneling is less secure than dual stack or translation.
B. Tunneling is more difficult to configure than dual stack or translation.
C. Tunneling does not enable users of the new protocol to communicate with users of the old protocol without dual-stack hosts.
D. Tunneling destinations are manually determined by the IPv4 address in the low-order 32 bits of IPv4-compatible IPv6 addresses.
Answer: C
Explanation:
Using the tunneling option, organizations build an overlay network that tunnels one protocol over the other
by encapsulating IPv6 packets within IPv4 packets and IPv4 packets within IPv6 packets. The advantage of this approach is that the new protocol can work without disturbing the old protocol, thus providing connectivity between users of the new protocol. Tunneling has two disadvantages, as discussed in RFC 6144: Users of the new architecture cannot use the services of the underlying infrastructure.
Tunneling does not enable users of the new protocol to communicate with users of the old protocol without
dual-stack hosts, which negates interoperability.
Reference: http://www.cisco.com/c/en/us/products/
collateral/ios-nx-os-software/enterprise-ipv6- solution/white_paper_c11-676278.html
Q4. The enterprise network WAN link has been receiving several denial of service attacks from both IPv4 and IPv6 sources. Which three elements can you use to identify an IPv6 packet via its header, in order to filter future attacks? (Choose three.)
A. Traffic Class
B. Source address
C. Flow Label
D. Hop Limit
E. Destination Address
F. Fragment Offset
Answer: A,C,D
Explanation:
Q5. Which prefix is matched by the command ip prefix-list name permit 10.8.0.0/16 ge 24 le 24?
A. 10.9.1.0/24
B. 10.8.0.0/24
C. 10.8.0.0/16
D. 10.8.0.0/23
Answer: B
Explanation:
With prefix lists, the ge 24 term means greater than or equal to a /24 and the le 24 means less than or
equal to /24, so only a /24 is both greater than or equal to 24 and less than or equal to 24. This translate to any prefix in the 10.8.x.0/24 network, where X is any value in the 0-255 range.
Only the choice of 10.8.0.0.24 matches this.
Q6. A user is having issues accessing file shares on a network. The network engineer advises the user to open a web browser, input a prescribed IP address, and follow the instructions. After doing this, the user is able to access company shares. Which type of remote access did the engineer enable?
A. EZVPN
B. IPsec VPN client access
C. VPDN client access
D. SSL VPN client access
Answer: D
Explanation:
The Cisco AnyConnect VPN Client provides secure SSL connections to the security
appliance for remote users. Without a previously installed client, remote users enter the IP address in their
browser of an interface configured to accept SSL VPN connections. Unless the security appliance is
configured to redirect http:// requests to https://, users must enter the URL in the form https://<address>.
After entering the URL, the browser connects to that interface and displays the login screen. If the user
satisfies the login and authentication, and the security appliance identifies the user as requiring the client, it
downloads the client that matches the operating system of the remote computer. After downloading, the
client installs and configures itself, establishes a secure SSL connection and either remains or uninstalls
itself (depending on the security appliance configuration) when the connection terminates. Reference:
http://www.cisco.com/c/en/us/support/docs/security/asa-5500-x-series-next- generation-firewalls/100936-
asa8x-split-tunnel-anyconnect-config.html
Q7. CORRECT TEXT
JS Industries has expanded their business with the addition of their first remote office. The remote office router (R3) was previously configured and all corporate subnets were reachable from R3. JS Industries is interested in using route summarization along with the EIGRP Stub Routing feature to increase network stability while reducing the memory usage and bandwidth utilization to R3. Another network professional was tasked with implementing this solution. However, in the process of configuring EIGRP stub routing connectivity with the remote network devices off of R3 has been lost.
Currently EIGRP is configured on all routers R2, R3, and R4 in the network. Your task is to identify and resolve the cause of connectivity failure with the remote office router R3. Once the issue has been resolved you should complete the task by configuring route summarization only to the remote office router R3.
You have corrected the fault when pings from R2 to the R3 LAN interface are successful, and the R3 IP routing table only contains 2 10.0.0.0 subnets.
Answer: Here are the solution as below:
Explanation:
First we have to figure out why R3 and R4 can not communicate with each other. Use the show running-config command on router R3.
Notice that R3 is configured as a stub receive-only router. The receive-only keyword will restrict the router from sharing any of its routes with any other router in that EIGRP autonomous system. This keyword will also prevent any type of route from being sent. Therefore we will remove this command and replace it with the eigrp stub command:
R3# configure terminal
R3(config)# router eigrp 123
R3(config-router)# no eigrp stub receive-only
R3(config-router)# eigrp stub
R3(config-router)# end
Now R3 will send updates containing its connected and summary routes to other routers. Notice that the eigrp stub command equals to the eigrp stub connected summary because the connected and summary options are enabled by default. Next we will configure router R3 so that it has only 2 subnets of 10.0.0.0 network. Use the show ip route command on R3 to view its routing table:
Because we want the routing table of R3 only have 2 subnets so we have to summary sub-networks at the interface which is connected with R3, the s0/0 interface of R4.
There is one interesting thing about the output of the show ip route shown above: the 10.2.3.0/24, which is a directly connected network of R3. We can’t get rid of it in the routing table no matter what technique we use to summary the networks. Therefore, to make the routing table of R3 has only 2 subnets we have to summary other subnets into one subnet.
In the output if we don’t see the summary line (like 10.0.0.0/8 is a summary…) then we should use the command ip summary-address eigrp 123 10.2.0.0 255.255.0.0 so that all the ping can work well.
In conclusion, we will use the ip summary-address eigrp 123 10.2.0.0 255.255.0.0 at the interface s0/0 of R4 to summary.
R4> enable
R4# conf t
R4(config)# interface s0/0
R4(config-if)# ip summary-address eigrp 123 10.2.0.0 255.255.0.0
Now we jump back to R3 and use the show ip route command to verify the effect, the output is shown below:
Note: Please notice that the IP addresses and the subnet masks in your real exam might be different so you might use different ones to solve this question. Just for your information, notice that if you use another network than 10.0.0.0/8 to summary, for example, if you use the command ip summary-address eigrp 123 10.2.0.0 255.255.0.0 you will leave a /16 network in the output of the show ip route command.
But in your real exam, if you don’t see the line "10.0.0.0/8 is a summary, Null0" then you can summarize using the network 10.2.0.0/16. This summarization is better because all the pings can work well. Finally don’t forget to use the copy run start command on routers R3 and R4 to save the configurations. R3(config-if)# end R3# copy run start R4(config-if)# end R4# copy run start
If the “copy run start” command doesn’t work then use “write memory.”
Q8. How does an IOS router process a packet that should be switched by Cisco Express Forwarding without an FIB entry?
A. by forwarding the packet
B. by dropping the packet
C. by creating a new FIB entry for the packet
D. by looking in the routing table for an alternate FIB entry
Answer: B
Explanation:
Q9. A network engineer executes the show crypto ipsec sa command. Which three pieces of information are displayed in the output? (Choose three.)
A. inbound crypto map
B. remaining key lifetime
C. path MTU
D. tagged packets
E. untagged packets
F. invalid identity packets
Answer: A,B,C
Explanation:
show crypto ipsec sa This command shows IPsec SAs built between peers. The encrypted
tunnel is built between 12.1.1.1 and 12.1.1.2 for traffic that goes between networks 20.1.1.0 and 10.1.1.0.
You can see the two Encapsulating Security Payload (ESP) SAs built inbound and outbound.
Authentication Header (AH) is not used since there are
no AH SAs.
This output shows an example of the show crypto ipsec sa command (bolded ones found in answers for
this question).
interface: FastEthernet0
Crypto map tag: test, local addr. 12.1.1.1
local ident (addr/mask/prot/port): (20.1.1.0/255.255.255.0/0/0) remote ident (addr/mask/prot/port):
(10.1.1.0/255.255.255.0/0/0) current_peer: 12.1.1.2
PERMIT, flags={origin_is_acl,}
#pkts encaps: 7767918, #pkts encrypt: 7767918, #pkts digest 7767918 #pkts decaps: 7760382, #pkts
decrypt: 7760382, #pkts verify 7760382 #pkts compressed:
0, #pkts decompressed: 0
#pkts not compressed: 0, #pkts compr. failed: 0,
#pkts decompress failed: 0, #send errors 1, #recv errors 0 local crypto endpt.: 12.1.1.1, remote crypto
endpt.: 12.1.1.2 path mtu 1500, media mtu 1500
current outbound spi: 3D3
inbound esp sas:
spi: 0x136A010F(325714191)
transform: esp-3des esp-md5-hmac ,
in use settings ={Tunnel, }
slot: 0, conn id: 3442, flow_id: 1443, crypto map: test sa timing: remaining key lifetime (k/sec):
(4608000/52) IV size: 8 bytes
replay detection support: Y
inbound ah sas:
inbound pcp sas:
inbound pcp sas:
outbound esp sas:
spi: 0x3D3(979)
transform: esp-3des esp-md5-hmac ,
in use settings ={Tunnel, }
slot: 0, conn id: 3443, flow_id: 1444, crypto map: test sa timing: remaining key lifetime (k/sec):
(4608000/52) IV size: 8 bytes
replay detection support: Y
outbound ah sas:
outbound pcp sas:
Reference: http://www.cisco.com/c/en/us/support/docs/security-vpn/ipsec-negotiation-ike- protocols/5409-
ipsec-debug-00.html
Q10. Which switching method is used when entries are present in the output of the command show ip cache?
A. fast switching
B. process switching
C. Cisco Express Forwarding switching
D. cut-through packet switching
Answer: A
Explanation:
Fast switching allows higher throughput by switching a packet using a cache created by the initial packet
sent to a particular destination. Destination addresses are stored in the high-speed cache to expedite forwarding. Routers offer better packet-transfer performance when fast switching is enabled. Fast switching is enabled by default on all interfaces that support fast switching.
To display the routing table cache used to fast switch IP traffic, use the "show ip cache" EXEC command.
Reference:
http://www.cisco.com/c/en/us/td/docs/ios/12_2/switch/command/reference/fswtch_r/xrfscmd5.ht
ml#wp1038133