Packet Tracer Video Tutorial 1
Wednesday, October 15, 2008
Saturday, October 11, 2008
ESwitching Chapter 6 - CCNA Exploration: LAN Switching and Wireless (Version 4.0) - Question and Answer
ESwitching Chapter 6 - CCNA Exploration: LAN Switching and Wireless (Version 4.0)
With answer
With answer
Refer to the exhibit. Switch1 is correctly configured for the VLANs that are displayed in the graphic. The configuration that is shown was applied to RTA to allow for interVLAN connectivity between hosts attached to Switch1. After testing the network, the administrator logged the following report:
Hosts within each VLAN can communicate with each other.
Hosts in VLAN5 and VLAN33 are able to communicate with each other.
Hosts connected to Fa0/1 through Fa0/5 do not have connectivity to host in other VLANs.
Why are hosts connected to Fa0/1 through Fa0/5 unable to communicate with hosts in different VLANs?
The router interface is shut down.
The VLAN IDs do not match the subinterface numbers.
All of the subinterface addresses on the router are in the same subnet.
The router was not configured to forward traffic for VLAN2.
The physical interface, FastEthernet0/0, was not configured with an IP address.
Refer to the exhibit. R1 is routing between networks 192.168.10.0/28 and 192.168.30.0/28. PC1 can ping R1 interface F0/1, but cannot ping PC3. What is causing this failure?
PC1 and PC3 are not in the same VLAN.
The PC3 network address configuration is incorrect.
The S1 interface F0/11 should be assigned to VLAN30.
The F0/0 and F0/1 interfaces on R1 must be configured as trunks.
Refer to the exhibit. Port Fa0/0 on router R1 is connected to port Fa0/1 on switch S1. After the commands shown are entered on both devices, the network administrator determines that the devices on VLAN 2 are unable to ping the devices on VLAN 1. What is the likely problem?
R1 is configured for router-on-a-stick, but S1 is not configured for trunking.
R1 does not have the VLANs entered in the VLAN database.
Spanning Tree Protocol is blocking port Fa0/0 on R1.
The subinterfaces on R1 have not been brought up with the no shutdown command yet.
Refer to the exhibit. PC1 has attempted to ping PC2 but has been unsuccessful. What could account for this failure?
PC1 and R1 interface F0/0.1 are on different subnets.
The encapsulation is missing on the R1 interface F0/0.
An IP address has not been assigned to the R1 physical interface.
The encapsulation command on the R1 F0/0.3 interface is incorrect.
5. A router has two FastEthernet interfaces and needs to connect to four VLANs in the local network. How can this be accomplished using the fewest number of physical interfaces without unnecessarily decreasing network performance?
Implement a router-on-a-stick configuration.
Add a second router to handle the inter-VLAN traffic.
Use a hub to connect the four VLANS with a FastEthernet interface on the router.
Interconnect the VLANs via the two additional FastEthernet interfaces.
Refer to the exhibit. Which three statements describe the network design shown in the exhibit? (Choose three.)
This design will not scale easily.
The router merges the VLANs into a single broadcast domain.
This design uses more switch and router ports than are necessary.
This design exceeds the maximum number of VLANs that can be attached to a switch.
This design requires the use of the ISL or 802.1q protocol on the links between the switch and the router.
If the physical interfaces between the switch and router are operational, the devices on the different VLANs can communicate through the router.
7. In which situation could individual router physical interfaces be used for InterVLAN routing, instead of a router-on-a-stick configuration?
a network with more than 100 subnetworks
a network with a limited number of VLANs
a network with experienced support personnel
a network using a router with one LAN interface
8. What distinguishes traditional routing from router-on-a-stick?
Traditional routing is only able to use a single switch interface. Router-on-a-stick can use multiple switch interfaces.
Traditional routing requires a routing protocol. Router-on-a-stick only needs to route directly connected networks.
Traditional routing uses one port per logical network. Router-on-a-stick uses subinterfaces to connect multiple logical networks to a single router port.
Traditional routing uses multiple paths to the router and therefore requires STP. Router-on-a-stick does not provide multiple connections and therefore eliminates the need for STP.
Refer to the exhibit. The commands for a router to connect to a trunked uplink are shown in the exhibit. A packet is received from IP address 192.168.1.54. The packet destination address is 192.168.1.120. What will the router do with this packet?
The router will forward the packet out interface FastEthernet 0/1.1 tagged for VLAN 10.
The router will forward the packet out interface FastEthernet 0/1.2 tagged for VLAN 60.
The router will forward the packet out interface FastEthernet 0/1.3 tagged for VLAN 120.
The router will not process the packet since the source and destination are on the same subnet.
The router will drop the packet since no network that includes the source address is attached to the router.
10. Which three elements must be used when configuring a router interface for VLAN trunking? (Choose three.)
one subinterface per VLAN
one physical interface for each subinterface
one IP network or subnetwork for each subinterface
one trunked link per VLAN
a management domain for each subinterface
a compatible trunking protocol encapsulation for each subinterface
11. What are the steps which must be completed in order to enable inter-VLAN routing using router-on-a-stick?
Configure the physical interfaces on the router and enable a routing protocol.
Create the VLANs on the router and define the port membership assignments on the switch.
Create the VLANs on the switch to include port membership assignment and enable a routing protocol on the router.
Create the VLANs on the switch to include port membership assignment and configure subinterfaces on the router matching the VLANs.
12. What two statements are true regarding the use of subinterfaces for inter-VLAN routing? (Choose two.)
subinterfaces have no contention for bandwidth
more switch ports required than in traditional inter-VLAN routing
fewer router ports required than in traditional inter-VLAN routing
simpler Layer 3 troubleshooting than with traditional inter-VLAN routing
less complex physical connection than in traditional inter-VLAN routing
Refer to the exhibit. All devices are configured as shown in the exhibit. PC2 can successfully ping the F0/0 interface on R1. PC2 cannot ping PC1. What might be the reason for this failure?
R1 interface F0/1 has not been configured for subinterface operation.
S1 interface F0/6 needs to be configured for operation in VLAN10.
S1 interface F0/8 is in the wrong VLAN.
S1 port F0/6 is not in VLAN10.
14. What is important to consider while configuring the subinterfaces of a router when implementing inter-VLAN routing?
The physical interface must have an IP address configured.
The subinterface numbers must match the VLAN ID number.
The no shutdown command must be given on each subinterface.
The IP address of each subinterface must be the default gateway address for each VLAN subnet
15.
Refer to the exhibit. The network administrator correctly configures RTA to perform inter-VLAN routing. The administrator connects RTA to port 0/4 on SW2, but inter-VLAN routing does not work. What could be the possible cause of the problem with the SW2 configuration?
Port 0/4 is not active.
Port 0/4 is not a member of VLAN1.
Port 0/4 is configured in access mode.
Port 0/4 is using the wrong trunking protocol.
Refer to the exhibit. What two conclusions can be drawn from the output that is shown? (Choose two.)
The no shutdown command has not been issued on the FastEthernet 0/0 interface.
Both of the directly connected routes that are shown will share the same physical interface of the router.
A routing protocol must be configured on the network in order for the inter-VLAN routing to be successful.
Inter-VLAN routing between hosts on the 172.17.10.0/24 and 172.17.30.0/24 networks is successful on this network.
Hosts in this network must be configured with the IP address that is assigned to the router physical interface as their default gateway.
17. Devices on the network are connected to a 24-port Layer 2 switch that is configured with VLANs. Switch ports 0/2 to 0/4 are assigned to VLAN 10. Ports 0/5 to 0/8 are assigned to VLAN 20, and ports 0/9 to 0/12 are assigned to VLAN 30. All other ports are assigned to the default VLAN. Which solution allows all VLANs to communicate between each other while minimizing the number of ports necessary to connect the VLANs?
Configure ports 0/13 to 0/16 with the appropriate IP addresses to perform routing between VLANs.
Add a router to the topology and configure one FastEthernet interface on the router with multiple subinterfaces for VLANs 1, 10, 20, and 30.
Obtain a router with multiple LAN interfaces and configure each interface for a separate subnet, thereby allowing communication between VLANs.
Obtain a Layer 3 switch and configure a trunk link between the switch and router, and configure the router physical interface with an IP address on the native VLAN.
18. Which statement is true about ARP when inter-VLAN routing is being used on the network?
When router-on-a-stick inter-VLAN routing is in use, each subinterface has a separate MAC address to send in response to ARP requests.
When VLANs are in use, the switch responds to ARP requests with the MAC address of the port to which the PC is connected.
When router-on-a-stick inter-VLAN routing is in use, the router returns the MAC address of the physical interface in response to ARP requests.
When traditional inter-VLAN routing is in use, devices on all VLANs use the same physical router interface as their source of proxy ARP responses.
Refer to the exhibit. Which two statements are true about the operation of the subinterfaces? (Choose two.)
Incoming traffic that has a VLAN ID of 2 is processed by subinterface fa0/0.2.
Incoming traffic with VLAN ID 0 is processed by interface fa0/0.
Subinterfaces use unique MAC addresses by adding the 802.1Q VLAN ID to the hardware address.
Traffic inbound on this router is processed by different subinterfaces, depending on the VLAN from which the traffic originated.
Reliability of both subinterfaces is poor because ARP is timing out.
Both subinterfaces remain up with line protocol up, even if fa0/0 line protocol is down.
20. Which two statements are true about the interface fa0/0.10 command? (Choose two.)
The command applies VLAN 10 to router interface fa0/0.
The command is used in the configuration of router-on-a-stick inter-VLAN routing.
The command configures a subinterface.
The command configures interface fa0/0 as a trunk link.
Because the IP address is applied to the physical interface, the command does not include an IP address
Thursday, October 9, 2008
Troubleshooting Ipconfig
Troubleshooting Ipconfig
An error occurred while renewing interface
Can ping ip but not name
Can ping IP but not hostname after installed/upgraded software
Can receive IP packets but not send them
Can't obtain/renew IP addresses from the DHCP server
Can't ping my own IP address
Cannot use the 2nd NIC
IP address conflicts
No IP while the network cable is disconnected
No operation can be performed on the adapter
One-way ping only
Some Win9x obtain different subnet mask
The DHCP client has obtained an IP address that is already in use on the network
Unexpected network failure or insufficient access or access is denied
Why the ipconfig shows 0.0.0.0 ip even you have assigned a static ip
Why do I get 169.254.x.x IP?
An error occurred while renewing interface
Symptoms: When trying to release and renew the IP address using the Ipconfig command, you may receive the following error message: “An error occurred while renewing interface 'Internet': An operation was attempted on something that is not a socket.”
Cause: These issues may occur if the Winsock registry keys are damaged or corrupted.
Can ping ip but not name
I have a situation here where I could ping an IP of a computer but how come I couldn't ping with its computer name?
1. Incorrect WINS and DNS settings.
2. Incorrect TCP/IP settings
3. Check lmhosts and hosts files
Can ping IP but not hostname after installed/upgraded software
Cause: the may modify the networking configuration in registry.
Can receive IP packets but not send them
Symptoms: When using ipconfig command, you may have no IP address or no Automatic Private IP Addressing (APIPA) address. You may be receiving IP packets but not sending them.
Cause: These issues may occur if the Winsock registry keys are damaged or corrupted.
Can't ping my own IP address
Failure to ping a computer's own IP address is most likely caused by a firewall program or improperly configured.
Can't obtain/renew IP addresses from the DHCP server
Symptoms: 1) you have a DHCP client which may not be able to obtain/renew IP addresses from the DHCP server intermittently. 2) after setup a workstation to obtain an IP address from DHCP, the machine can't ping others and ipconfig /all shows Autoconfiguration IP Address. . . : 169.254.x.x.
Resolutions: 1) If this is XP, obtain the latest service pack for Windows XP.
2) Use the Network Diagnostics tool to identify any failed settings. To do this, go to Help and Support>Use Tools to view your computer information and diagnose problems>Network Diagnostics>Scan your system. When the process finishes, check for any items marked "FAILED" in red, expand those categories, and view the additional details about what the testing showed.
3) Assign a static ip on the client and ping the DHCP server. If you can't ping the DHCP server, check the connection and hardware.
4) If you can ping the DHCP after assigning static ip, check the DHCP settings.
5) Make sure no firewall is running on your LAN.
6) Run Repair this connection if it is XP. Or use netsh to reset TCP/IP configuration.
7) If it is win98/w2k, remove and reinstall TCP/IP.
8) Try to upgrade the new NIC driver.
9) Make sure you don't run out of IPs in the DHCP scope.
10) If you use a router as DHCP, you may want to upgrade the firmware.
Cannot use the 2nd NIC
Symptom: You have two computers and each one has two NICs. You are using the first NIC with 192.168.1.0/24 to connect the Internet and it works. You also want to use the 2nd NIC with crossover cable to connect to each other using the same IP range (one is 192.168.1.10 and another is 192.168.1.11). You can't ping each other (192.168.1.10 and 192.168.1.11).
Resolution: The 2nd NICs should use the different IP range.
IP address conflicts
SYMPTOMS: when trying to set the IP address on a NIC, you may receive the following error message: "The IP address XXX.XXX.XXX.XXX you have entered for this network adapter is already assigned to another adapter Name of adapter. Name of adapter is hidden from the network and Dial-up Connections folder because it is not physically in the computer or is a legacy adapter that is not working. If the same address is assigned to both adapters and they become active, only one of them will use this address. This may result in incorrect system configuration. Do you want to enter a different IP address for this adapter in the list of IP addresses in the advanced dialog box? "
RESOLUTION:
1. If you click Yes, you see the TCP/IP properties where you can change the IP address. Then assign the different IP.
2. If you click No, the IP address is assigned to the network adapter. To resolve this problem, uninstall the ghosted network adapter from the registry: At command prompt, type set devmgr_show_nonpresent_devices=1, and then press ENTER. Type Start DEVMGMT.MSC, and then press ENTER. Click View, and then click Show Hidden Devices. Expand the Network Adapters tree and right-click the dimmed network adapter, and then click Uninstall.
No IP while the network cable is disconnected
Symptoms: your computer has a static IP. However, the ipconfig shows no IP (Media State - Cable Disconnected) while the network cable is disconnected.
Cause: this is by design. If you have some software using TCP/IP whiteout connecting to a network, you may setup it manually.
No operation can be performed on the adapter
Symptoms: when attempting to use ipconfig /release or renew command, you get "No operation can be performed on the adapter as this connection has its media/cable disconnected.
Causes: 1. The network is up-plugged or no NIC. 2. You are using static IP.
One-way ping only
If you can ping other computers and other computers can't ping your computer, this is often caused by an improperly configured firewall
on you computer. For example, ICF should not be enabled on LAN NIC.
Some Win9x obtain different subnet mask
Symptoms: In your domain network, some computers (most are win9x) obtain mask 255.255.255.0 instead of 255.0.0.0 randomly and they can't logon to the Domain. IPCONFIG /renew doesn't fix the problem. If you assign static ip and correct mask, the computer will be able to logon without any problem. If you check the WINS, you may find many bad records.
Possible reasons: you may have another network device (possible a router) except main DHCP functions as a DHCP.
The DHCP client has obtained an IP address that is already in use on the network
Symptom: When trying to renew IP, you may get this error "An error occurred while renewing the interface Local Area Connection: The
DHCP client has obtained an IP address that is already in use on the network. The local interface will be disabled until the DHCP client can obtain a new address."
Resolution: 1. Release and the renew it.
2. Clean the internal DNS and WINS records.
Refer to case 083104LR
Unexpected network failure or insufficient access or access is denied
Symptoms: when trying to use ipconfig /release or renew, you may receive the following message "The following error occurred when releasing adapter Local Area Connection: Unexpected network failure or insufficient access or access is denied"
Cause: You don't have permission to release or renew the IP.
Why do I get 169.254.x.x IP?
Symptom: The Internet Assigned Numbers Authority (IANA) has reserved 169.254.0.0-169.254.255.255 for Automatic Private IP Addressing. If the computer can't get ip from DHCP, APIPA provides an address that is guaranteed not to conflict with routable addresses.
Resolutions: 1) Make sure you have good connection.
2) Check the hardware and settings.
3) Make sure the DHCP is working.
4) For the test, you can assign static ip. If static ip works, it is possible DHCP issue. If static ip doesn't work, check the hardware or connection.
5) WinSock2 stack may be corrupted and need to repair.
Why the ipconfig shows 0.0.0.0 ip even you have assigned a static ip
Question: I have assigned a static ip, subnet to the computer, but the ipconfig shows IP address is 0.0.0.0 and subnet mask 0.0.0.0.. Why?
Answer: An existing IP address on the network has the same IP address. You may use tracert ip, WINS and DNS records to find out another computer using the same IP.
If your laptop users frequently disconnect from one network segment and reconnect to another network segment, they may not be able to access the second network. Resolution will be run ipconfig /registerdns.
An error occurred while renewing interface
Can ping ip but not name
Can ping IP but not hostname after installed/upgraded software
Can receive IP packets but not send them
Can't obtain/renew IP addresses from the DHCP server
Can't ping my own IP address
Cannot use the 2nd NIC
IP address conflicts
No IP while the network cable is disconnected
No operation can be performed on the adapter
One-way ping only
Some Win9x obtain different subnet mask
The DHCP client has obtained an IP address that is already in use on the network
Unexpected network failure or insufficient access or access is denied
Why the ipconfig shows 0.0.0.0 ip even you have assigned a static ip
Why do I get 169.254.x.x IP?
An error occurred while renewing interface
Symptoms: When trying to release and renew the IP address using the Ipconfig command, you may receive the following error message: “An error occurred while renewing interface 'Internet': An operation was attempted on something that is not a socket.”
Cause: These issues may occur if the Winsock registry keys are damaged or corrupted.
Can ping ip but not name
I have a situation here where I could ping an IP of a computer but how come I couldn't ping with its computer name?
1. Incorrect WINS and DNS settings.
2. Incorrect TCP/IP settings
3. Check lmhosts and hosts files
Can ping IP but not hostname after installed/upgraded software
Cause: the may modify the networking configuration in registry.
Can receive IP packets but not send them
Symptoms: When using ipconfig command, you may have no IP address or no Automatic Private IP Addressing (APIPA) address. You may be receiving IP packets but not sending them.
Cause: These issues may occur if the Winsock registry keys are damaged or corrupted.
Can't ping my own IP address
Failure to ping a computer's own IP address is most likely caused by a firewall program or improperly configured.
Can't obtain/renew IP addresses from the DHCP server
Symptoms: 1) you have a DHCP client which may not be able to obtain/renew IP addresses from the DHCP server intermittently. 2) after setup a workstation to obtain an IP address from DHCP, the machine can't ping others and ipconfig /all shows Autoconfiguration IP Address. . . : 169.254.x.x.
Resolutions: 1) If this is XP, obtain the latest service pack for Windows XP.
2) Use the Network Diagnostics tool to identify any failed settings. To do this, go to Help and Support>Use Tools to view your computer information and diagnose problems>Network Diagnostics>Scan your system. When the process finishes, check for any items marked "FAILED" in red, expand those categories, and view the additional details about what the testing showed.
3) Assign a static ip on the client and ping the DHCP server. If you can't ping the DHCP server, check the connection and hardware.
4) If you can ping the DHCP after assigning static ip, check the DHCP settings.
5) Make sure no firewall is running on your LAN.
6) Run Repair this connection if it is XP. Or use netsh to reset TCP/IP configuration.
7) If it is win98/w2k, remove and reinstall TCP/IP.
8) Try to upgrade the new NIC driver.
9) Make sure you don't run out of IPs in the DHCP scope.
10) If you use a router as DHCP, you may want to upgrade the firmware.
Cannot use the 2nd NIC
Symptom: You have two computers and each one has two NICs. You are using the first NIC with 192.168.1.0/24 to connect the Internet and it works. You also want to use the 2nd NIC with crossover cable to connect to each other using the same IP range (one is 192.168.1.10 and another is 192.168.1.11). You can't ping each other (192.168.1.10 and 192.168.1.11).
Resolution: The 2nd NICs should use the different IP range.
IP address conflicts
SYMPTOMS: when trying to set the IP address on a NIC, you may receive the following error message: "The IP address XXX.XXX.XXX.XXX you have entered for this network adapter is already assigned to another adapter Name of adapter. Name of adapter is hidden from the network and Dial-up Connections folder because it is not physically in the computer or is a legacy adapter that is not working. If the same address is assigned to both adapters and they become active, only one of them will use this address. This may result in incorrect system configuration. Do you want to enter a different IP address for this adapter in the list of IP addresses in the advanced dialog box? "
RESOLUTION:
1. If you click Yes, you see the TCP/IP properties where you can change the IP address. Then assign the different IP.
2. If you click No, the IP address is assigned to the network adapter. To resolve this problem, uninstall the ghosted network adapter from the registry: At command prompt, type set devmgr_show_nonpresent_devices=1, and then press ENTER. Type Start DEVMGMT.MSC, and then press ENTER. Click View, and then click Show Hidden Devices. Expand the Network Adapters tree and right-click the dimmed network adapter, and then click Uninstall.
No IP while the network cable is disconnected
Symptoms: your computer has a static IP. However, the ipconfig shows no IP (Media State - Cable Disconnected) while the network cable is disconnected.
Cause: this is by design. If you have some software using TCP/IP whiteout connecting to a network, you may setup it manually.
No operation can be performed on the adapter
Symptoms: when attempting to use ipconfig /release or renew command, you get "No operation can be performed on the adapter
Causes: 1. The network is up-plugged or no NIC. 2. You are using static IP.
One-way ping only
If you can ping other computers and other computers can't ping your computer, this is often caused by an improperly configured firewall
on you computer. For example, ICF should not be enabled on LAN NIC.
Some Win9x obtain different subnet mask
Symptoms: In your domain network, some computers (most are win9x) obtain mask 255.255.255.0 instead of 255.0.0.0 randomly and they can't logon to the Domain. IPCONFIG /renew doesn't fix the problem. If you assign static ip and correct mask, the computer will be able to logon without any problem. If you check the WINS, you may find many bad records.
Possible reasons: you may have another network device (possible a router) except main DHCP functions as a DHCP.
The DHCP client has obtained an IP address that is already in use on the network
Symptom: When trying to renew IP, you may get this error "An error occurred while renewing the interface Local Area Connection: The
DHCP client has obtained an IP address that is already in use on the network. The local interface will be disabled until the DHCP client can obtain a new address."
Resolution: 1. Release and the renew it.
2. Clean the internal DNS and WINS records.
Refer to case 083104LR
Unexpected network failure or insufficient access or access is denied
Symptoms: when trying to use ipconfig /release or renew, you may receive the following message "The following error occurred when releasing adapter Local Area Connection: Unexpected network failure or insufficient access or access is denied"
Cause: You don't have permission to release or renew the IP.
Why do I get 169.254.x.x IP?
Symptom: The Internet Assigned Numbers Authority (IANA) has reserved 169.254.0.0-169.254.255.255 for Automatic Private IP Addressing. If the computer can't get ip from DHCP, APIPA provides an address that is guaranteed not to conflict with routable addresses.
Resolutions: 1) Make sure you have good connection.
2) Check the hardware and settings.
3) Make sure the DHCP is working.
4) For the test, you can assign static ip. If static ip works, it is possible DHCP issue. If static ip doesn't work, check the hardware or connection.
5) WinSock2 stack may be corrupted and need to repair.
Why the ipconfig shows 0.0.0.0 ip even you have assigned a static ip
Question: I have assigned a static ip, subnet to the computer, but the ipconfig shows IP address is 0.0.0.0 and subnet mask 0.0.0.0.. Why?
Answer: An existing IP address on the network has the same IP address. You may use tracert ip, WINS and DNS records to find out another computer using the same IP.
If your laptop users frequently disconnect from one network segment and reconnect to another network segment, they may not be able to access the second network. Resolution will be run ipconfig /registerdns.
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