10 Question and Answer

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How the Data Link Layer process the data ?

From the sending host it receives each packet on the network layer. After wraps up the packet in a data frame along with local routing data it finaly sends the data frame to the physical layer to code as a signal.
On the receiving host side it unwraps the received data frame and extracts the data packet from the data frame and finally sends the packet up to the network layer.

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Tell me how the switch is functioning .

Initially it learns a MAC addressess of all the devices that are connected to the switch. and forward the frames to destination host after deciding whether that frames it received from the host devices or other switches, also it avoids creating any layer 2 loops.

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Functions of a switch.

Address learning, Flooding, Forwarding, Filtering, and avoiding loops.

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Tell me the Use of Boot command cisco devices.

Boot command that allows you to configure the cisco switches boot process.

• which control the loaded cisco ios image file.
• Control the loaded the startup configuration file.
• It enables the ctrl + break during booting.
• Also enabling the manual booting.

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How do you recover the password of a switch ?

These are the steps involved with the password-recovery mechanism enabled,

• Step 1 : Interrupt the boot process with ctrl+ Break
• Step 2 : Initialize the flash file system manually
• Step 3 : Prevent the ios loading of startup configuration file by hiding
• Step 4 : Manually boot the switch and wait till the ios to finish loading in RAM.
• Step 5 : unhide the startup config file and manually load it from NVRAM to RAM
• Step 6 : Reset the password
• Step 7 : Save the running config as startup config
• Step 8 : Revert the boot process and reboot the switch

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How do you recover the switch password if the password-recovery mechanism is disabled ?

These are the steps :

• Step 1 : Interrupt the normal boot by pressing ctrl+Break
• Step 2 : On the default config mode accept to reset the switch.
• Step 3 : Manually boot the switch and wait for the ios to finish loading in RAM.
• Step 4 : Now Reset the password
• Step 5 : Save the running config as a startup config
• Step 6 : Revert the Boot process to its default options and reboot the switch

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How the VTP Transparent mode works in a switch ?

A VTP transparentswitch maintains its own local VLAN database, and does not directly participate in the VTP domain. A transparent switch will never accept VLAN database information from anotherswitch, even a server. Also, a transparent switch will never advertise its local VLAN database to another switch.

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What are the VTP message advertisement types ?

Three message types exist for VTP advertisements:

• Summary Advertisement
• Subset Advertisement
• Advertisement Request

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Tell me the important rules of access lists ?

1. If a bit is set to 0in a wild-card mask, the corresponding bit in the address must be matched exactly.
2. If a bit is set to 1 in a wild-card mask, the corresponding bit in the address can match any number.

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What is HDLC ?

High-Level Data-link Control (HDLC)is a WAN encapsulation protocol used on dedicated point-to-point serial lines.