What is Cisco xmodem?

What is Cisco xmodem?

It is just a file tranfer protocol. It is used a lot for Cisco devices when there is no IOS on the different devices therefore only console access is available. Under such conditions, xmodem is used to push the software (mostlikely IOS) in order to have “normal” access to the device once again.

How do I find the flash directory on a Cisco switch?

dir. The dir command shows files in a directory, and the default directory is usually the Flash file system. So, entering dir displays the directory of flash:/ by default. You can also specify which directory you want to view, or you can use the all-filesystemsoption.

Which protocol can be used to load or retrieve Cisco IOS images to or from a router?

Using TFTP The most common of the methods used when transferring Cisco IOS images to and from devices is TFTP. The TFTP protocol is a skinny form of the FTP protocol that utilizes UDP (rather than TCP) and thus does not provide any type of retransmission or reordering; it is, however, generally faster.

What is 0x2142 config register?

Configuration register is 0x2142. In this example, the configuration register shows 0x2142. The router bypasses the startup configuration stored in NVRAM during its boot sequence. This feature is normally used during a password recovery procedure.

What is Post Cisco?

The Power-On Self Test (POST) is a process which occurs on almost every computer during bootup. This process is used to test the router hardware. When the router is powered on, software on the ROM chip performs tests on several hardware components, such as CPU, RAM and NVRAM.

What is another name for flash Cisco?

ROM stands for Read-Only Memory. ROM stores the routers bootstrap startup program, operating system software, and power-on diagnostic test programs (the POST). Flash memory is generally referred to as flash The Cisco Internetwork Operating System (IOS) images are held here.

Where is IOS stored in a Cisco router?

There are at least two main pieces of non-volatile storage in a Cisco router. The router’s configuration information is stored in a device called the Non-Volatile RAM (NVRAM), and the IOS images are stored in a device called the flash (lowercase).

Which is more secure FTP or TFTP?

In terms of security, SFTP is the easy winner: SFTP encrypts your data in transit (TFTP doesn’t encrypt your data at all). Plus, SFTP authenticates your connection with your choice of user ID and password or SSH keys with or instead of a password. TFTP has no security.

What is the difference between YMODEM/CRC and xmodem-1k/xmodem?

XMODEM/CRC replaces XMODEM’s 1 byte checksum with a two byte Cyclical Redundancy Check (CRC-16), giving modern error detection protection. XMODEM-1k Refers to the XMODEM/CRC protocol with 1024 byte data blocks. YMODEM Refers to the XMODEM/CRC (optional 1k blocks) protocol with batch transmission as described below.

How does XMODEM work?

XMODEM was offering a block length of 128 bytes and a 8-bit checksum followed at the end of each block. With XMODEM a file were transferred one packet at a time. The protocol is completely receiver controlled. When each data packet received, the packet’s checksum was calculated and compared to the one received.

What is the difference between XMODEM-1K and Y Modem-G?

XMODEM-1k Refers to the XMODEM/CRC protocol with 1024 byte data blocks. YMODEM Refers to the XMODEM/CRC (optional 1k blocks) protocol with batch transmission as described below. In a nutshell, YMODEM means BATCH. YMODEM-g Refers to the streaming YMODEM variation described below.

How to transfer files from XMODEM to Mac?

Once you press enter, you see the following: Begin the Xmodem or Xmodem-1K transfer now… At this point, you need to choose the file location from the terminal program. Go under File -> Transfer -> Xmodem -> Send and choose the file that you wish the transfer.