IPv6的ACL配置及注意点

  IPv6ACL规则如下:

  1 只能使用命名的ACL

  2 ACL序号匹配由小到大

  3 默认情况下,隐含permit icmp any any nd-na 和permit icmp anyany nd-ns 用于邻居发现协议的邻居通告和邻居请求,允许接口发送和接收IPv6邻居发现包。

  3 结尾默认隐含 deny ipv6 any any

  4 使用命令ipv6 traffic-filter应用于接口的in or out方向

  IPv6的ACL配置及注意点

  需求:在R1配置ACL,禁止R1的环回接口访问R4的环回接口地址;

  ACL配置如下,其它配置略:

  R1(config)#ipv6 access-list Mao

  R1(config-ipv6-acl)#deny 2011::1/1282044::4/128

  R1(config-ipv6-acl)#permit any any

  R1(config)#int fa0/0

  R1(config-if)#ipv6 traffic-filter Mao out

  R1#show ipv6 access-list

  IPv6 access list Mao

  deny ipv6 host 2011::1 host 2044::4 sequence 10

  permit ipv6 anyany sequence 20

  R1#ping 2044::4 source 2011::1

  Type escape sequence to abort.

  Sending 5, 100-byte ICMP Echos to 2044::4,timeout is 2 seconds:

  Packet sent with a source address of2011::1

  !!!!!

  Success rate is 100 percent (5/5),round-trip min/avg/max = 24/36/52 ms

  为什么会ping通呢?是因为命令ipv6 traffic-filter的作用是过滤路由器转发的流量,但不过滤源自本路由器的流量;

  现在将ACL进行修改如下,拒绝从R4环回接口发回来的数据包,并将ACL应用至fa0/0的入接口方向上;

  R1(config)#ipv6access-list Mao

  R1(config-ipv6-acl)#no deny ipv6 host 2011::1 host 2044::4

  R1(config-ipv6-acl)#deny ipv6 2044::4/128 2011::1/128

  R1(config-ipv6-acl)#permit any any

  R1(config-if)#no ipv6 traffic-filter Mao out

  R1(config-if)#ipv6 traffic-filter Mao in

  R1#ping2044::4 source 2011::1

  Type escape sequence to abort.

  Sending 5, 100-byte ICMP Echos to 2044::4,timeout is 2 seconds:

  Packet sent with a source address of2011::1

  …..

  Success rate is 0 percent (0/5)

  R1#show access-lists

  IPv6 access list Mao

  deny ipv6 host 2044::4 host 2011::1 (5 matches) sequence 30 //匹配了5个数据包

  permit ipv6 anyany (4 matches) sequence 40

  总结:命令ipv6traffic-filter不过滤源自本路由器的流量,因此在配置IPv6 ACL时需要注意流量的起源是否来至本路由器。

  以上例子也可以在R3上配置,如下:

  R3(config)#ipv6access-list Mao

  R3(config-ipv6-acl)#deny ipv6 2011::1/128 2044::4/128

  R3(config-ipv6-acl)#permit any any

  R3(config)#int fa0/1

  R3(config-if)#ipv6 traffic-filter Mao out

  R1#ping 2044::4 source 2011::1

  Type escape sequence to abort.

  Sending 5, 100-byte ICMP Echos to 2044::4,timeout is 2 seconds:

  Packet sent with a source address of2011::1

  SSSSS

  Success rate is 0 percent (0/5)

  不通,在R1和R3之间抓包可知,如下图:

IPv6的ACL配置及注意点

  的类型为1,表示目标不可达,代码字段为5,源地址被入站/出站策略所阻止。

    文章来源:http://muyun.blog.51cto.com/952166/1605876

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