「ICMPv6」- 报文格式

在 IPv6 Header 中,当 Next-Header == 58 时,则对应为 ICMPv6 报文。

报文格式

Type:表明消息的类型。ICMPv6 报文载荷由 ICMPv6 报文 Type 字段决定,因报文类型的不同而不同。

Code:表示消息类型的细分。

Checksum:表示 ICMPv6 报文的校验和。

Message Body:报文内容。对于 ping 报文,其中包含随机数据;对于类型为 NS NA RS RA 的报文,其中包含结构化的数据和相关信息。

报文示例

ICMPv6 Request and ICMPv6 Reply

Request

Frame 14: 118 bytes on wire (944 bits), 118 bytes captured (944 bits) on interface -, id 0
Ethernet II, Src: 38:39:cc:01:01:00 (38:39:cc:01:01:00), Dst: 38:39:cc:02:01:00 (38:39:cc:02:01:00)
Internet Protocol Version 6, Src: 2000:12::1, Dst: 2000:12::2
    0110 .... = Version: 6
    .... 0000 0000 .... .... .... .... .... = Traffic Class: 0x00 (DSCP: CS0, ECN: Not-ECT)
        .... 0000 00.. .... .... .... .... .... = Differentiated Services Codepoint: Default (0)
        .... .... ..00 .... .... .... .... .... = Explicit Congestion Notification: Not ECN-Capable Transport (0)
    .... 0000 0000 0000 0000 0000 = Flow Label: 0x00000
    Payload Length: 64
    Next Header: ICMPv6 (58)
    Hop Limit: 64
    Source Address: 2000:12::1
        [Address Space: Global Unicast]
    Destination Address: 2000:12::2
        [Address Space: Global Unicast]
    [Stream index: 0]
Internet Control Message Protocol v6
    Type: Echo (ping) request (128)
    Code: 0
    Checksum: 0x82fb [correct]
    [Checksum Status: Good]
    Identifier: 0x2400
    Sequence: 256
    [Response In: 15]
    Data (56 bytes)
        Data: 001100000101ff01504e47000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
        [Length: 56]

Reply

Frame 15: 118 bytes on wire (944 bits), 118 bytes captured (944 bits) on interface -, id 0
Ethernet II, Src: 38:39:cc:02:01:00 (38:39:cc:02:01:00), Dst: 38:39:cc:01:01:00 (38:39:cc:01:01:00)
Internet Protocol Version 6, Src: 2000:12::2, Dst: 2000:12::1
    0110 .... = Version: 6
    .... 0000 0000 .... .... .... .... .... = Traffic Class: 0x00 (DSCP: CS0, ECN: Not-ECT)
        .... 0000 00.. .... .... .... .... .... = Differentiated Services Codepoint: Default (0)
        .... .... ..00 .... .... .... .... .... = Explicit Congestion Notification: Not ECN-Capable Transport (0)
    .... 0000 0000 0000 0000 0000 = Flow Label: 0x00000
    Payload Length: 64
    Next Header: ICMPv6 (58)
    Hop Limit: 64
    Source Address: 2000:12::2
        [Address Space: Global Unicast]
    Destination Address: 2000:12::1
        [Address Space: Global Unicast]
    [Stream index: 0]
Internet Control Message Protocol v6
    Type: Echo (ping) reply (129)
    Code: 0
    Checksum: 0x81fb [correct]
    [Checksum Status: Good]
    Identifier: 0x2400
    Sequence: 256
    [Response To: 14]
    [Response Time: 0.000 ms]
    Data (56 bytes)
        Data: 001100000101ff01504e47000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
        [Length: 56]