asa防火墻基本上網綜合實驗

實驗要求：

分別劃分inside（內網），outside（外網），dmz（服務器區）三個區

配置PAT，直接使用outside接口的ip地址進行轉換

配置靜態NAT，發布內網服務器

啟用NAT控制，配置NAT豁免，內網訪問dmz區中的主機時，不做NAT轉換

R1配置：

R1#conf t

Enter configuration commands, one per line.  End with CNTL/Z.

R1(config)#host outsite

outsite(config)#int f0/0

outsite(config-if)#ip add 12.0.0.2 255.255.255.0

outsite(config-if)#no shut

outsite(config-if)#int f0

00:21:15: %LINK-3-UPDOWN: Interface FastEthernet0/0, changed state to up

00:21:16: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/0, changed state to up

outsite(config-if)#int f0/1

outsite(config-if)#ip add 13.0.0.1 255.255.255.0

outsite(config-if)#no shut

outsite(config-if)#

00:21:33: %LINK-3-UPDOWN: Interface FastEthernet0/1, changed state to up

00:21:34: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/1, changed state to up

outsite(config-if)#exit

outsite(config)#ip route 0.0.0.0 0.0.0.0 f0/0

outsite(config)#end

ASA配置：

ciscoasa# conf t

ciscoasa(config)# hostname asa

asa(config)# int e0/0

asa(config-if)# nameif inside

INFO: Security level for "inside" set to 100 by default.

asa(config-if)# ip add 192.168.1.1 255.255.255.0

asa(config-if)# no shut

asa(config-if)# int e0/2

asa(config-if)# nameif outside

INFO: Security level for "outside" set to 0 by default.

asa(config-if)# ip add 12.0.0.1 255.255.255.0

asa(config-if)# no shut

asa(config-if)# int e0/1

asa(config-if)# ip add 192.168.10.1 255.255.255.0

asa(config-if)# no shut

asa(config-if)# nameif dmz

INFO: Security level for "dmz" set to 0 by default.

asa(config-if)# sec

asa(config-if)# security-level 50

asa(config-if)# no shut

asa(config-if)# exit

asa(config)# route outside 0 0 12.0.0.2

ciscoasa# conf t

ciscoasa(config)# nat-control

ciscoasa(config)# nat (inside) 1 192.168.1.0 255.255.255.0

ciscoasa(config)# gl

ciscoasa(config)# global (outside) 1 interface

INFO: outside interface address added to PAT pool

ciscoasa(config)# end

ciscoasa# show xlate

0 in use, 1 most used

ciscoasa# show xlate

1 in use, 1 most used

PAT Global 12.0.0.1(1) Local 192.168.1.2 ICMP id 1

很明顯的看出來已經把內網地址轉換成外網地址，從而可以讓內網用戶上網了

Ping不通是因為防火墻的原因，這里需要些acl放行

ciscoasa(config)# access-list 111 permit icmp any any

ciscoasa(config)# acc

ciscoasa(config)# access-g

ciscoasa(config)# access-group 111 in int

ciscoasa(config)# access-group 111 in interface outside

ciscoasa(config)# access-list nonat permit ip host 192.168.1.2 host 192.168.10.10  //豁免nat，也就是說從內網訪問到dmz區域的流量不走nat，直接走內網。

ciscoasa(config)# nat (inside) 0 access-list nonat

再次測試就ok了

因為默認高到低是可以通的，所以內網訪問dmz區無需配置，測試如下：

靜態NAT（發布DMZ區的服務器）一對一的固定轉換：

ciscoasa(config)#  static (dmz,outside) 12.0.0.3 192.168.10.10

ciscoasa(config)# access-list out_to_dmz permit tcp any host 12.0.0.3 eq www

ciscoasa(config)# access-group out_to_dmz in int outside

ciscoasa(config)# exit

外網驗證如下：