防火墙不断启动
Use BREAK or ESC to interrupt boot.
Use SPACE to begin boot immediately.

按下ESC进入监控模式
监控模式下的显示和交换机路由器没有什么区别。命令格式也大同小异只要大家变通一下就不难恢复。
rommon #1> ？
Variables: Use "sync" to store in NVRAM
ADDRESS= local IP address
CONFIG= config file path/name
GATEWAY= gateway IP address
IMAGE= p_w_picpath file path/name
LINKTIMEOUT= Link UP timeout (seconds)
PKTTIMEOUT= packet timeout (seconds)
PORT= ethernet interface port
RETRY= Packet Retry Count (Ping/TFTP)
SERVER= server IP address
VLAN= enable/disable DOT1Q tagging on the selected port

rommon #2> ADDRESS=192.168.0.2 （因为是TFFP上传，所以防火墙设置为客户机）
rommon #3> GATEWAY=192.168.0.1 （网关）
rommon #4> IMAGE=asa802-k8.bin （导入IOS的名称）
rommon #5> SERVER=192.168.0.1 （服务器IP，也就是你的PC）
rommon #6> sync （保存）
Updating NVRAM Parameters...

rommon #7> ping 192.168.0.1

Sending 20, 100-byte ICMP Echoes to 192.168.0.1, timeout is 4 seconds:
?!!!!!!!!!!!!!!!!!!!
Success rate is 95 percent (19/20)
确认线路是否连通，开启TFTP软件 （这里说明下我测试是ASA5505 所以接的E0/0口。不知道设备该接什么口可以用set看“PORT=Ethernet0/0”）
rommon #8> tftpdnld （上传）
ROMMON Variable Settings:
ADDRESS=192.168.0.2
SERVER=192.168.0.1
GATEWAY=192.168.0.1
PORT=Ethernet0/0
VLAN=untagged
IMAGE=asa802-k8.bin
CONFIG=
LINKTIMEOUT=20
PKTTIMEOUT=4
RETRY=20

tftp asa802-k8.bin@192.168.0.1 via 192.168.0.1
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

导入后设备重启，现在有了IOS 能进去
Type help or '?' for a list of available commands.
ciscoasa> en
但现在IOS也没有装入设备，而是从tftp引导启动设备，断开TFTP服务器就会从新进入监控模式。这一点当设备启动完毕后可以用show version命令看到：
System p_w_picpath file is "tftp://192.168.0.1/asa802-k8.bin"

现在需要把IOS存入设备，但是现在防火墙和PC已经不能通信
ciscoasa# ping 192.168.0.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.0.1, timeout is 2 seconds:
No route to host 192.168.0.1

Success rate is 0 percent (0/1)
因为刚才是在监控模式下，现在需要配置让PC和防火墙从新通信（具体型号具体设置，下面已我手上的5505为例）

interface Vlan1
nameif inside
security-level 100
ip address 192.168.1.1 255.255.255.0
!
interface Vlan2
nameif outside
security-level 0
ip address 192.168.0.2 255.255.255.0
!
interface Ethernet0/0
switchport access vlan 2
现在测试
ciscoasa# ping 192.168.1.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.1.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/1 ms
已经能通信，下面拷贝IOS和ASDM存入设备

ciscoasa# copy tftp://192.168.0.1/asa802-k8.bin disk0:/asa802-k8.bin

Address or name of remote host ?

Source filename ?

Destination filename ?

Accessing tftp://192.168.0.1/asa802-k8.bin. ... !!!!!!!!!!!!!!!!!!!
因为删除的是flash 现在还需要导入ASDM （注意ASDM和IOS的兼容，不兼容如下图）
http://p6.p_w_picpaths22.51img1.com/6000/wokgj/63bae1b142c03799a009ea9d52bc4dc8.jpg
ciscoasa# copy tftp://192.168.0.1/asdm-602.bin disk0://asdm-602.bin

Address or name of remote host ?

Source filename ?

Destination filename ?
Accessing tftp://192.168.0.1/asdm-602.bin.. ... !!!!!!!!!!!!!!!!!!!
现在可以看见IOS以后在设备上
ciscoasa# show version

Cisco Adaptive Security Appliance Software Version 8.2(1)

Compiled on Tue 05-May-09 22:45 by builders
System p_w_picpath file is "disk0:/asa821-k8.bin"
Config file at boot was "startup-config"



ciscoasa# show flash:
--#-- --length-- -----date/time------ path
3 4096 Aug 26 2009 17:41:50 log
10 4096 Aug 26 2009 17:41:56 crypto_archive
11 4096 Aug 26 2009 17:59:06 coredumpinfo
12 43 Aug 27 2009 09:13:02 coredumpinfo/coredump.cfg
78 16275456 Aug 26 2009 18:07:50 asa802-k8.bin
80 7598456 Aug 27 2009 09:05:54 asdm-602.bin
设置启动文件
ciscoasa (config)# boot system disk0:/asa802-k8.bin 设置IOS
ciscoasa (config)# asdm p_w_picpath disk0:/asdm602.bin 设置ASDM
ciscoasa (config)# reload 重新启动，配置生效

备份上面dir的文件
ciscoasa (config)# copy disk0:/asa802-k8.bin tftp://192.168.1.1/asa802-k8.bin
ciscoasa (config)# copy disk0:/asdm602.bin tftp://192.168.1.1/asdm602.bin