防火墙F100-C-G5 ,打开链路下ARP功能，开启IP + MAC地址绑定

终端直连防火墙上网正常，进行ip-mac绑定后，无法上网。

关键配置：

ip-mac binding enable

ip-mac binding no-match action deny

ip-mac binding ipv4 100.64.34.134 mac-address 7440-4aa0-7852

ip-mac binding ipv4 192.168.156.118 mac-address 011d-bcf8-4e1b

安全策略放通区域为any-any，不涉及被安全策略阻断的问题。

查看会话发现无回包：

<H3C>display session table ipv4 source-ip 192.168.156.118 destination-ip 114.114.114.114 verbos

Slot 1:

Initiator:

  Source      IP/port: 192.168.156.118/1

  Destination IP/port: 114.114.114.114/2048

  DS-Lite tunnel peer: -

  VPN instance/VLAN ID/Inline ID: -/-/-

  Protocol: ICMP(1)

  Inbound interface: Vlan-interface100

  Source security zone: Trust

Responder:

  Source      IP/port: 114.114.114.114/146

  Destination IP/port: 100.64.34.134/0

  DS-Lite tunnel peer: -

  VPN instance/VLAN ID/Inline ID: -/-/-

  Protocol: ICMP(1)

  Inbound interface: Dialer0

  Source security zone: Untrust

State: ICMP_REQUEST

Application: ICMP

Rule ID: 1

Rule name: test

Start time: 2021-11-16 15:50:58  TTL: 30s

Initiator->Responder:            4 packets        240 bytes

Responder->Initiator:            0 packets          0 bytes

Total sessions found: 1

随后通过抓包及debug发现报文在dialer口被丢掉：

*Nov 16 15:49:11:384 2021 H3C IPFW/7/IPFW_INFO:

MBUF was intercepted! Phase Num is 0(pre all), Service ID is 3(ip mac), Bitmap is 1000000000000000, return 1(0:continue, 1:dropped, 2:consumed, 3:enqueued, 4:relay)! Interface is Dialer0,

s= 114.114.114.114, d= 100.64.34.134, protocol= 1, pktid = 64507.

原因分析：配置IP-MAC绑定功能的设备接收到用户报文后，会提取报文头中的源IP地址和源MAC地址，并与IP-MAC绑定表项进行匹配。

来自外网的报文并没有建立IP-MAC的表项关系，所以被丢弃。

在内网接口下配置IP-MAC的绑定，但是要注意防火墙的版本是否支持。