场景说明：PC3、PC2分别属于租户A、B，互相不能访问，整个网络为VXLAN网络，通过分布式网关部署，网关落于Leaf设备，Spine同时作为Border Leaf和Service Leaf三合一角色。防火墙主备部署，开启虚墙功能，不同租户使用不同虚墙，业务层面逻辑隔离，具体信息如上图所示。在防火墙上做SNAT使内部设备可以访问公网。
流量走向：PC3访问PE（模拟访问公网）路径为： PC3->Leaf->Spine（租户侧）->防火墙（Trust侧)->防火墙(Untrust侧)->Spine（Internet侧）-PE。

Leaf配置：

sysname Leaf
#
evpn-overlay enable
#
evpn
#
ip vpn-instance A  //配置租户A的vrf
 ipv4-family
  route-distinguisher 1:10000
  vpn-target 1:10000 export-extcommunity evpn
  vpn-target 1:10000 import-extcommunity evpn
 vxlan vni 10000
#
ip vpn-instance B  //配置租户B的vrf
 ipv4-family
  route-distinguisher 1:10001
  vpn-target 1:10001 export-extcommunity evpn
  vpn-target 1:10001 import-extcommunity evpn
 vxlan vni 10001
#
bridge-domain 10010  //建立vxlan 10010与vlan10关联的BD
 vxlan vni 10010
 evpn
  route-distinguisher 1:10010
  vpn-target 1:10010 export-extcommunity
  vpn-target 1:10000 export-extcommunity
  vpn-target 1:10010 import-extcommunity
#
bridge-domain 10020 //建立vxlan 10020与vlan20关联的BD
 vxlan vni 10020
 evpn
  route-distinguisher 1:10020
  vpn-target 1:10020 export-extcommunity
  vpn-target 1:10001 export-extcommunity
  vpn-target 1:10020 import-extcommunity
#
interface Vbdif10010  //配置分布式网关
 ip binding vpn-instance A
 ip address 192.168.10.254 255.255.255.0
 arp collect host enable //用于感知主机上线，收集主机信息
#
interface Vbdif10020  //配置分布式网关
 ip binding vpn-instance B
 ip address 192.168.20.254 255.255.255.0
 arp collect host enable //用于感知主机上线，收集主机信息
#
interface GE1/0/0
 undo portswitch
 undo shutdown
 ip address 10.0.12.2 255.255.255.252
 ospf network-type p2p
#
interface GE1/0/9.10 mode l2
 encapsulation dot1q vid 10
 bridge-domain 10010
#
interface GE1/0/9.20 mode l2
 encapsulation dot1q vid 20
 bridge-domain 10020
#
interface LoopBack0
 ip address 1.1.1.2 255.255.255.255
#
interface Nve1
 source 1.1.1.2
 vni 10010 head-end peer-list protocol bgp
 vni 10020 head-end peer-list protocol bgp
#
bgp 100
 peer 1.1.1.1 as-number 100
 peer 1.1.1.1 connect-interface LoopBack0
 #
 ipv4-family unicast
  undo peer 1.1.1.1 enable
 #
 l2vpn-family evpn
  policy vpn-target
  peer 1.1.1.1 enable
  peer 1.1.1.1 advertise irb
#
ospf 1
 area 0.0.0.0
  network 1.1.1.2 0.0.0.0
  network 10.0.12.0 0.0.0.3
#
return

Spine配置：

sysname Spine
#
vlan batch 11 21 100 to 101
#
evpn-overlay enable
#
evpn
#
ip vpn-instance A //配置租户A的vrf
 ipv4-family
  route-distinguisher 1:10000
  vpn-target 1:10000 export-extcommunity evpn
  vpn-target 1:10000 import-extcommunity evpn
 vxlan vni 10000  //租户A的L3 VNI
#
ip vpn-instance B  //配置租户B的vrf
 ipv4-family    
  route-distinguisher 1:10001
  vpn-target 1:10001 export-extcommunity evpn
  vpn-target 1:10001 import-extcommunity evpn
 vxlan vni 10001 //租户B的L3 VNI
#
ip vpn-instance Internet
 ipv4-family
  route-distinguisher 100:100
  vpn-target 100:100 export-extcommunity
  vpn-target 100:100 import-extcommunity
#
bfd
#
bridge-domain 10011
 vxlan vni 10011
 evpn
  route-distinguisher 1:10011
  vpn-target 1:10011 export-extcommunity
  vpn-target 1:10000 export-extcommunity
  vpn-target 1:10011 import-extcommunity
#
bridge-domain 10021
 vxlan vni 10021
 evpn
  route-distinguisher 1:10021
  vpn-target 1:10021 export-extcommunity
  vpn-target 1:10001 export-extcommunity
  vpn-target 1:10021 import-extcommunity
#
interface Vbdif10011  //与租户A虚墙互联接口
 ip binding vpn-instance A
 ip address 10.0.11.4 255.255.255.248
#
interface Vbdif10021  //与租户B虚墙互联接口
 ip binding vpn-instance B
 ip address 10.0.21.4 255.255.255.248
#
interface Vlanif100  //租户A虚墙与Internet侧互联接口
 ip binding vpn-instance Internet
 ip address 10.0.100.4 255.255.255.248
#
interface Vlanif101  //租户B虚墙与Internet侧互联接口
 ip binding vpn-instance Internet
 ip address 10.0.101.4 255.255.255.248
#
interface GE1/0/0
 undo portswitch
 undo shutdown
 ip binding vpn-instance Internet
 ip address 100.0.0.2 255.255.255.252
#
interface GE1/0/3
 undo shutdown
 port link-type trunk
 port trunk allow-pass vlan 100 to 101
#
interface GE1/0/3.11 mode l2
 encapsulation dot1q vid 11
 bridge-domain 10011
#
interface GE1/0/3.21 mode l2
 encapsulation dot1q vid 21
 bridge-domain 10021
#
interface GE1/0/4
 undo shutdown
 port link-type trunk
 port trunk allow-pass vlan 100 to 101
#
interface GE1/0/4.11 mode l2
 encapsulation dot1q vid 11
 bridge-domain 10011
#
interface GE1/0/4.21 mode l2
 encapsulation dot1q vid 21
 bridge-domain 10021
#
interface GE1/0/9
 undo portswitch
 undo shutdown
 ip address 10.0.12.1 255.255.255.252
 ospf network-type p2p
#
interface LoopBack0
 ip address 1.1.1.1 255.255.255.255
#
interface Nve1
 source 1.1.1.1
 vni 10011 head-end peer-list protocol bgp
 vni 10021 head-end peer-list protocol bgp
#
bgp 100
 peer 1.1.1.2 as-number 100
 peer 1.1.1.2 connect-interface LoopBack0
 #
 ipv4-family unicast
  undo peer 1.1.1.2 enable
 #
 ipv4-family vpn-instance A //通过BGP EVPN 给租户A发布缺省路由
  default-route imported
  import-route static
  advertise l2vpn evpn
 #              
 ipv4-family vpn-instance B //通过BGP EVPN 给租户B发布缺省路由
  default-route imported
  import-route static
  advertise l2vpn evpn
 #
 l2vpn-family evpn
  policy vpn-target
  peer 1.1.1.2 enable
  peer 1.1.1.2 advertise irb
  peer 1.1.1.2 reflect-client
#
ospf 1
 area 0.0.0.0
  network 1.1.1.1 0.0.0.0
  network 10.0.12.0 0.0.0.3
#
ospf 100 vpn-instance Internet
 default-route-advertise
 bfd all-interfaces enable
 area 0.0.0.0
  network 10.0.100.0 0.0.0.7
  network 10.0.101.0 0.0.0.7
#               
ip route-static vpn-instance Internet 0.0.0.0 0.0.0.0 100.0.0.1
ip route-static vpn-instance A 0.0.0.0 0.0.0.0 10.0.11.1
ip route-static vpn-instance B 0.0.0.0 0.0.0.0 10.0.21.1
#
return

防火墙（租户A虚墙相关配置）配置都差不多：

根墙下配置：
#
vsys name A 1  //给虚墙A分配资源
 assign interface GigabitEthernet1/0/2.11
 assign interface GigabitEthernet1/0/2.100
 assign global-ip 100.0.1.0 100.0.1.255 exclusive
#
ospf 1 vpn-instance A  //虚墙A与Internet侧建立OSPF
 bfd all-interfaces enable
 import-route static route-policy import_static_A //发布公网业务路由
 area 0.0.0.0
  network 10.0.100.0 0.0.0.7
#
route-policy import_static_A permit node 10
 if-match ip-prefix import_static_A
#
route-policy import_static_A deny node 20
#
ip ip-prefix import_static_A index 10 permit 100.0.1.0 24


虚墙A配置：
#
switch vsys A
#
interface GigabitEthernet1/0/2.11
 vlan-type dot1q 11
 ip binding vpn-instance A
 ip address 10.0.11.2 255.255.255.248
 vrrp vrid 1 virtual-ip 10.0.11.1 active
 service-manage ping permit
#
interface GigabitEthernet1/0/2.100
 vlan-type dot1q 100
 ip binding vpn-instance A
 ip address 10.0.100.2 255.255.255.248
 vrrp vrid 2 virtual-ip 10.0.100.1 active 
 service-manage ping permit
#
interface Virtual-if1
#
firewall zone local
 set priority 100
#
firewall zone trust
 set priority 85
 add interface GigabitEthernet1/0/2.11
#
firewall zone untrust
 set priority 5
 add interface GigabitEthernet1/0/2.100
#
firewall zone dmz
 set priority 50
#
nat address-group SNAT_1 0
 mode pat                                 
 section 0 100.0.1.1 100.0.1.1
#
security-policy
 rule name Trust_Untrust
  source-zone trust
  destination-zone untrust
  action permit
#
nat-policy
 rule name Trust_Untrust
  source-zone trust
  destination-zone untrust
  source-address 192.168.10.0 mask 255.255.255.0
  action source-nat address-group SNAT_1  //主备墙不建议用easy_ip的方式做SNAT
#                                         
ip route-static 100.0.1.0 255.255.255.0 NULL0 //为分配给虚墙A的公网业务路由做黑洞路由
ip route-static 192.168.10.0 255.255.255.0 10.0.11.4
#
return

实验结果：

PC2可以正常访问公网，同理PC3也一样

防火墙主备切换发生丢包，然后恢复通讯

防火墙回切导致丢包