防火墙USG做NAT产生路由环路及解决方法

Posted 2020-11-18

1、 根据拓扑连接设备，配置pc和服务器地址
2、 防火墙基本配置

接口地址
interface GigabitEthernet0/0/0
alias GE0/MGMT
ip address 192.168.1.254 255.255.255.0

interface GigabitEthernet0/0/1
ip address 192.168.2.254 255.255.255.0

interface GigabitEthernet0/0/2
ip address 200.1.1.1 255.255.255.0

接口加入到区域
firewall zone trust
add interface GigabitEthernet0/0/0

firewall zone untrust
add interface GigabitEthernet0/0/2

firewall zone dmz
add interface GigabitEthernet0/0/1

要求三
先放行出去在ICMP流量
policy interzone trust untrust outbound
policy 1
action permit
policy service service-set icmp
创建地址池，
[SRG]nat address-group 0 pool1 200.100.100.1 200.100.100.10
创建NAT策略
[SRG]nat-policy interzone trust untrust outbound
[SRG-nat-policy-interzone-trust-untrust-outbound]policy 1
[SRG-nat-policy-interzone-trust-untrust-outbound-1]
policy source any

[SRG-nat-policy-interzone-trust-untrust-outbound-1]policy destination any
[SRG-nat-policy-interzone-trust-untrust-outbound-1]action source-nat
[SRG-nat-policy-interzone-trust-untrust-outbound-1]address-group pool1 [SRG-nat-policy-interzone-trust-untrust-outbound-1]q
[SRG ]ip roue-static 0.0.0.0 0.0.0.0 200.1.1.2

在防火墙接口开启抓包功能
用路由器去ping –c 1 200.100.100.1
看到抓包效果

说明路由形成路由环路，

地址池路由汇总
200.100.100.00000001
200.100.100.00001010
200.100.100.0/28

在防火墙上做黑洞路由
ip route-static 100.1.1.0 28 NULL 0
在防火墙接口开启抓包功能
用路由器去ping –c 1 200.100.100.1

（图片上的目标地址应该是200.100.100.1，我实验用的是100.1.1.1）
环路消除

Easy-ip 配置
[SRG-nat-policy-interzone-trust-untrust-outbound-1]undo address-group
[SRG-nat-policy-interzone-trust-untrust-outbound-1]easy-ip g0/0/2
先ping 流量出去再看会话状态
[SRG]display firewall session table

可以看到都映射200.1.1.1出接口

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