配置FW_A。
a.配置接口的IP地址，并将接口加入安全区域。 system-view
[sysname] sysname FW_A
[FW_A] interface GigabitEthernet 1/0/1
[FW_A-GigabitEthernet1/0/1] ip address 1.1.1.1 24
[FW_A-GigabitEthernet1/0/1] quit
[FW_A] interface GigabitEthernet 1/0/2
[FW_A-GigabitEthernet1/0/2] ip address 10.1.1.1 24
[FW_A-GigabitEthernet1/0/2] quit
[FW_A] interface Tunnel 1
[FW_A-Tunnel1] ip address 172.16.2.1 24
[FW_A-Tunnel1] quit
[FW_A] firewall zone untrust
[FW_A-zone-untrust] add interface GigabitEthernet 1/0/1
[FW_A-zone-untrust] quit
[FW_A] firewall zone trust
[FW_A-zone-trust] add interface GigabitEthernet 1/0/2
[FW_A-zone-trust] quit
[FW_A] firewall zone dmz
[FW_A-zone-dmz] add interface tunnel 1
[FW_A-zone-dmz] quit

b.配置路由，将需要经过GRE隧道传输的流量引入到GRE隧道中。
[FW_A] ip route-static 10.1.2.0 24 Tunnel1
不用静态用ospf也可以
network发布隧道地址和内网地址

[FW_A] ip route-static 0.0.0.0 0 1.1.1.2

c.配置Tunnel接口的封装参数。[FW_A] interface Tunnel 1
[FW_A-Tunnel1] tunnel-protocol gre
[FW_A-Tunnel1] source 1.1.1.1
[FW_A-Tunnel1] destination 5.5.5.5
[FW_A-Tunnel1] gre key cipher 123456 //gre连接验证
[FW_A-Tunnel1] keepalive //验证对端是否存活，避免数据流量黑洞

d.配置域间安全策略。
配置Trust域和DMZ的域间安全策略，允许封装前的报文通过域间安全策略。
[FW_A] security-policy
[FW_A-policy-security] rule name policy1
[FW_A-policy-security-rule-policy1] source-zone trust dmz
[FW_A-policy-security-rule-policy1] destination-zone dmz trust
[FW_A-policy-security-rule-policy1] action permit
[FW_A-policy-security-rule-policy1] quit

配置Local和Untrust的域间安全策略，允许封装后的GRE报文通过域间安全策略。
[FW_A-policy-security] rule name policy2
[FW_A-policy-security-rule-policy2] source-zone local untrust
[FW_A-policy-security-rule-policy2] destination-zone untrust local
[FW_A-policy-security-rule-policy2] service gre
[FW_A-policy-security-rule-policy2] action permit
[FW_A-policy-security-rule-policy2] quit

2.配置FW_B。
a.配置接口的IP地址，并将接口加入安全区域。 system-view
[sysname] sysname FW_B
[FW_B] interface GigabitEthernet 1/0/1
[FW_B-GigabitEthernet1/0/1] ip address 5.5.5.5 24
[FW_B-GigabitEthernet1/0/1] quit
[FW_B] interface GigabitEthernet 1/0/2
[FW_B-GigabitEthernet1/0/2] ip address 10.1.2.1 24
[FW_B-GigabitEthernet1/0/2] quit
[FW_B] interface Tunnel 1
[FW_B-Tunnel1] ip address 172.16.2.2 24
[FW_B-Tunnel1] quit
[FW_B] firewall zone untrust
[FW_B-zone-untrust] add interface GigabitEthernet 1/0/1
[FW_B-zone-untrust] quit
[FW_B] firewall zone trust
[FW_B-zone-trust] add interface GigabitEthernet 1/0/2
[FW_B-zone-trust] quit
[FW_B] firewall zone dmz
[FW_B-zone-dmz] add interface tunnel 1
[FW_B-zone-dmz] quit

b.配置路由，将需要经过GRE隧道传输的流量引入到GRE隧道中。
[FW_B] ip route-static 10.1.1.0 24 Tunnel1

[FW_A] ip route-static 0.0.0.0 0 5.5.5.1

c.配置Tunnel接口的封装参数。[FW_B] interface Tunnel 1
[FW_B-Tunnel1] tunnel-protocol gre
[FW_B-Tunnel1] source 5.5.5.5
[FW_B-Tunnel1] destination 1.1.1.1
[FW_B-Tunnel1] gre key cipher 123456
[FW_B-Tunnel1] quit

d.配置域间安全策略。
配置Trust域和DMZ的域间安全策略，允许封装前的报文通过域间安全策略。
[FW_B] security-policy
[FW_B-policy-security] rule name policy1
[FW_B-policy-security-rule-policy1] source-zone trust dmz
[FW_B-policy-security-rule-policy1] destination-zone dmz trust
[FW_B-policy-security-rule-policy1] action permit
[FW_B-policy-security-rule-policy1] quit

配置Local和Untrust的域间安全策略，允许封装后的GRE报文通过域间安全策略。
[FW_B-policy-security] rule name policy2
[FW_B-policy-security-rule-policy2] source-zone local untrust
[FW_B-policy-security-rule-policy2] destination-zone untrust local
[FW_B-policy-security-rule-policy2] service gre
[FW_B-policy-security-rule-policy2] action permit
[FW_B-policy-security-rule-policy2] quit