Use TFTP in rommon mode to fix IOS faults

This article gives you a detailed description of how to use TFTP to fix IOS faults in rommon mode. Here we will use a specific case to explain in detail.

The topology is as follows:

Fault description: R1 IOS cannot enter ios due to damage or loss, in this case, we can connect to the minimum Ethernet port of the router and set IP_ADDRESS, DEFAULT_GATEWAY, IP_ADDRESS_MASK, TFTP_SERVER, and TFTP_FILE parameters for f0/0 in rommon mode, and then use the tftpdnld command to establish a connection, download IOS

1. Connect the vrof0 f0/0 port to the network.

2. Configure TFTP for IOS download

1. Set the TFTP ip address 192.168.0.12, set the TFTP mask to 255.000003, and set the TFTP gateway to 192.168.0.254. skip this step on the same network. 4. Set the directory for TFTP to download IOS.

3. Set vro Parameters

1. In the absence of IOS, The ROMMON mode is enabled by default. In ROMMON mode, enter the following command to set the f0/0 interface parameter and TFTP server parameter IP_ADDRESS = 192.168.0.2.
IP_SUBNET_MASK = 255.255.255.0
DEFAULT_GATEWAY = 192.168.0.254
TFTP_SERVER = 192.168.0.1
TFTP_FILE = c2600-i-mz.122-28.bin

2. You can use the set command to view the set parameter rommon 11 & gt; set
DEFAULT_GATEWAY = 192.168.0.254
IP_ADDRESS = 192.168.0.2
IP_SUBNET_MASK = 255.255.255.0
PS1 = rommon! & Gt;
TFTP_FILE = c2600-i-mz.122-28.bin
TFTP_SERVER = 192.168.0.1

3. After confirming that the parameters are correct, enter tftpdnld to download IOSrommon 12 & gt; tftpdnld IP_ADDRESS: 192.168.0.2
IP_SUBNET_MASK: 255.255.255.0
DEFAULT_GATEWAY: 192.168.0.254
TFTP_SERVER: 192.168.0.1
TFTP_FILE: c2600-i-mz.122-28.bin
Invoke this command for disaster recovery only.
WARNING: all existing data in all partitions on flash will be lost! Do you wish to continue? Y/n: [n]:

Enter Y to start IOS4 download. After the download is complete, run the reset command to restart the router to load IOS