Cisco Router 重開機會進入rommon模式

請檢查映像檔是否還在及組態暫存器值，也可試著設定boot system

1.檢查falsh0內的IOS 映像檔是否還在
Cisco_Router#dir flash:
Directory of flash0:/

    1  -rw-    76900964   Sep 2 2015 14:11:48 +00:00  c1900-universalk9-mz.SPA.155-1.T1.bin
    2  -rw-        3066   Sep 2 2015 14:20:34 +00:00  cpconfig-19xx.cfg
    3  -rw-         720  Dec 29 2015 11:29:16 +00:00  vlan.dat
    4  drw-           0   Sep 2 2015 14:20:56 +00:00  ccpexp
  459  -rw-        2885   Sep 2 2015 14:24:46 +00:00  home.shtml

2.檢查當前的組態暫存器值是否為0x2102
Cisco_Router#show version

Configuration register is 0x2102

如果不是0x2102，更改指令如下
Cisco_Router#conf t
Cisco_Router(config)#config-register 0x2102
[Ctrl-Z]
Cisco_Router#reload

3.設定boot system
Cisco_Router#dir flash:
Directory of flash0:/

    1  -rw-    76900964   Sep 2 2015 14:11:48 +00:00  c1900-universalk9-mz.SPA.155-1.T1.bin
    2  -rw-        3066   Sep 2 2015 14:20:34 +00:00  cpconfig-19xx.cfg
    3  -rw-         720  Dec 29 2015 11:29:16 +00:00  vlan.dat
    4  drw-           0   Sep 2 2015 14:20:56 +00:00  ccpexp
  459  -rw-        2885   Sep 2 2015 14:24:46 +00:00  home.shtml

設定前，無boot system資料
Cisco_Router#show run | inc boot
boot-start-marker
boot-end-marker

Cisco_Router#conf t
Cisco_Router(config)#boot system flash0:c1900-universalk9-mz.SPA.155-1.T1.bin
[Ctrl-Z]
Cisco_Router#write

設定後
Cisco_Router#show run | inc boot
boot-start-marker
boot system flash0:c1900-universalk9-mz.SPA.155-1.T1.bin
boot-end-marker