3850 交换机是现在比较常用的三层交换机，有时候会因为异常掉电，或者其他说明原因导致IOS 损坏，如果IOS 丢失或者损坏，无法正常启动交换机了，如何恢复呢？ 分享一下3850 恢复IOS 的操作：
Step 1 From your PC, download the software image file (image.bin) from Cisco.com.
Step 2 Load the software image to your TFTP server.
Step 3 Connect your PC to the switch Ethernet management port.
Step 4 Unplug the switch power cord.
Step 5 Press the Mode button, and at the same time, reconnect the power cord to the switch.
Step 6 From the bootloader (ROMMON) prompt, ensure that you can ping your TFTP server.
switch: set IP_ADDR 192.0.2.123/255.255.255.0
switch: set DEFAULT_ROUTER 192.0.2.1
ping 测试一下到TFTP 是否正常通讯
switch: ping 192.0.2.15
Step 7 Verify that you have a recovery image in your recovery partition (sda9:).
This recovery image is required for recovery using the emergency-install feature.
Example:
switch: dir sda9:
Directory of sda9:/
2 drwx 1024 .
2 drwx 1024 ..
11 -rw- 18923068 c3850-recovery.bin
36939776 bytes available (20830208 bytes used)
Step 8 From the bootloader (ROMMON) prompt, initiate the emergency-install feature that assists you in recovering the software image on your switch.
WARNING: The emergency install command will erase your entire boot flash!
Example:
Switch#
emergency-install tftp://192.0.2.47/cat3k_caa-unive ... P.150-12.02.EZP.bin
The bootflash will be erased during install operation, continue (y/n)?y
Starting emergency recovery
(tftp://192.0.2.47/cat3k/cat3k_caa ... .00.SE.150-1.EX.bin)...
Reading full image into memory......................done
Nova Bundle Image
--------------------------------------
Kernel Address : 0x6042e5cc
Kernel Size : 0x318261/3244641
Initramfs Address : 0x60746830
Initramfs Size : 0xdb0fb9/14356409
Compression Format: .mzip
Bootable image at @ ram:0x6042e5cc
Bootable image segment 0 address range [0x81100000, 0x81b80000] is in range [0x80180000, 0x90000000].
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
File "sda9:c3850-recovery.bin" uncompressed and installed, entry point: 0x811060f0
Loading Linux kernel with entry point 0x811060f0 ...
Bootloader: Done loading app on core_mask: 0xf
### Launching Linux Kernel (flags = 0x5)
Initiating Emergency Installation of bundle
tftp://192.0.2.47/cat3k/cat3k_caa ... P.150-12.02.EZP.bin
Downloading bundle
tftp://192.0.2.47/cat3k/cat3k_caa ... 50-12.02.EZP.bin...
Validating bundle
tftp://192.0.2.47/cat3k/cat3k_caa ... 50-12.02.EZP.bin...
Installing bundle
tftp://192.0.2.47/cat3k/cat3k_caa ... 50-12.02.EZP.bin...
Verifying bundle
tftp://192.0.2.47/cat3k/cat3k_caa ... 50-12.02.EZP.bin...
Package cat3k_caa-base..pkg is Digitally Signed
Package cat3k_caa-drivers.SPA.03.02.00.SE.pkg is Digitally Signed
Package cat3k_caa-infra.SPA.03.02.00.SE.pkg is Digitally Signed
Package cat3k_caa-iosd-universalk9.SPA.03.02.00.SE.pkg is Digitally Signed
Package cat3k_caa-platform.SPA.03.02.00.SE.pkg is Digitally Signed
Package cat3k_caa-wcm.SPA.03.02.00.SE.pkg is Digitally Signed
Preparing flash...
Syncing device...
Emergency Install successful... Rebooting
Restarting system.
Booting...(use DDR clock 667 MHz)Initializing and Testing RAM +++@@@@####...++@@++@@++@@++@
Step 1 From your PC, download the software image file (image.bin) from Cisco.com.
Step 2 Load the software image to your TFTP server.
Step 3 Connect your PC to the switch Ethernet management port.
Step 4 Unplug the switch power cord.
Step 5 Press the Mode button, and at the same time, reconnect the power cord to the switch.
Step 6 From the bootloader (ROMMON) prompt, ensure that you can ping your TFTP server.
switch: set IP_ADDR 192.0.2.123/255.255.255.0
switch: set DEFAULT_ROUTER 192.0.2.1
ping 测试一下到TFTP 是否正常通讯
switch: ping 192.0.2.15
Step 7 Verify that you have a recovery image in your recovery partition (sda9:).
This recovery image is required for recovery using the emergency-install feature.
Example:
switch: dir sda9:
Directory of sda9:/
2 drwx 1024 .
2 drwx 1024 ..
11 -rw- 18923068 c3850-recovery.bin
36939776 bytes available (20830208 bytes used)
Step 8 From the bootloader (ROMMON) prompt, initiate the emergency-install feature that assists you in recovering the software image on your switch.
WARNING: The emergency install command will erase your entire boot flash!
Example:
Switch#
emergency-install tftp://192.0.2.47/cat3k_caa-unive ... P.150-12.02.EZP.bin
The bootflash will be erased during install operation, continue (y/n)?y
Starting emergency recovery
(tftp://192.0.2.47/cat3k/cat3k_caa ... .00.SE.150-1.EX.bin)...
Reading full image into memory......................done
Nova Bundle Image
--------------------------------------
Kernel Address : 0x6042e5cc
Kernel Size : 0x318261/3244641
Initramfs Address : 0x60746830
Initramfs Size : 0xdb0fb9/14356409
Compression Format: .mzip
Bootable image at @ ram:0x6042e5cc
Bootable image segment 0 address range [0x81100000, 0x81b80000] is in range [0x80180000, 0x90000000].
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
File "sda9:c3850-recovery.bin" uncompressed and installed, entry point: 0x811060f0
Loading Linux kernel with entry point 0x811060f0 ...
Bootloader: Done loading app on core_mask: 0xf
### Launching Linux Kernel (flags = 0x5)
Initiating Emergency Installation of bundle
tftp://192.0.2.47/cat3k/cat3k_caa ... P.150-12.02.EZP.bin
Downloading bundle
tftp://192.0.2.47/cat3k/cat3k_caa ... 50-12.02.EZP.bin...
Validating bundle
tftp://192.0.2.47/cat3k/cat3k_caa ... 50-12.02.EZP.bin...
Installing bundle
tftp://192.0.2.47/cat3k/cat3k_caa ... 50-12.02.EZP.bin...
Verifying bundle
tftp://192.0.2.47/cat3k/cat3k_caa ... 50-12.02.EZP.bin...
Package cat3k_caa-base..pkg is Digitally Signed
Package cat3k_caa-drivers.SPA.03.02.00.SE.pkg is Digitally Signed
Package cat3k_caa-infra.SPA.03.02.00.SE.pkg is Digitally Signed
Package cat3k_caa-iosd-universalk9.SPA.03.02.00.SE.pkg is Digitally Signed
Package cat3k_caa-platform.SPA.03.02.00.SE.pkg is Digitally Signed
Package cat3k_caa-wcm.SPA.03.02.00.SE.pkg is Digitally Signed
Preparing flash...
Syncing device...
Emergency Install successful... Rebooting
Restarting system.
Booting...(use DDR clock 667 MHz)Initializing and Testing RAM +++@@@@####...++@@++@@++@@++@
