请教DHCP封包最后一项options

[_china]

大家好,
请教DHCP封包最后一项options的详细资料,比如options段的开始处是否要写某些特定的数据,中间code+lenth+value 其中code所有可能的取值意义,结束处是否一定要以0xFF结束?
谢谢!

[iorikingdom]

很久很久以前研究过
好像RFC有,你look look看看,或者在协议网那里有资料,
另外
贱价出卖DHCP SERVER 源代码 ^_^

[blastzgd]

先UP一下

[月吻长河]

怎么又有人问这个问题。
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| op (1) | htype (1) | hlen (1) | hops (1) |
+---------------+---------------+---------------+---------------+
| xid (4) |
+-------------------------------+-------------------------------+
| secs (2) | flags (2) |
+-------------------------------+-------------------------------+
| ciaddr (4) |
+---------------------------------------------------------------+
| yiaddr (4) |
+---------------------------------------------------------------+
| siaddr (4) |
+---------------------------------------------------------------+
| giaddr (4) |
+---------------------------------------------------------------+
| |
| chaddr (16) |
| |
| |
+---------------------------------------------------------------+
| |
| sname (64) |
+---------------------------------------------------------------+
| |
| file (128) |
+---------------------------------------------------------------+
| |
| options (variable) |
+---------------------------------------------------------------+

Format of a DHCP message

/**************************************************************************/
FIELD OCTETS DESCRIPTION
----- ------ -----------

op 1 Message op code / message type.
1 = BOOTREQUEST, 2 = BOOTREPLY
htype 1 Hardware address type, see ARP section in "Assigned
Numbers" RFC; e.g., '1' = 10mb ethernet.
hlen 1 Hardware address length (e.g. '6' for 10mb
ethernet).
hops 1 Client sets to zero, optionally used by relay agents
when booting via a relay agent.
xid 4 Transaction ID, a random number chosen by the
client, used by the client and server to associate
messages and responses between a client and a
server.
secs 2 Filled in by client, seconds elapsed since client
began address acquisition or renewal process.
flags 2 Flags (see figure 2).
ciaddr 4 Client IP address; only filled in if client is in
BOUND, RENEW or REBINDING state and can respond
to ARP requests.
yiaddr 4 'your' (client) IP address.
siaddr 4 IP address of next server to use in bootstrap;
returned in DHCPOFFER, DHCPACK by server.
giaddr 4 Relay agent IP address, used in booting via a
relay agent.
chaddr 16 Client hardware address.
sname 64 Optional server host name, null terminated string.
file 128 Boot file name, null terminated string; "generic"
name or null in DHCPDISCOVER, fully qualified
directory-path name in DHCPOFFER.
options var Optional parameters field. See the options
documents for a list of defined options.

Description of fields in a DHCP message

[月吻长河]

Option DHCPOFFER DHCPACK DHCPNAK
------ --------- ------- -------
Requested IP address MUST NOT MUST NOT MUST NOT
IP address lease time MUST MUST (DHCPREQUEST) MUST NOT
MUST NOT (DHCPINFORM)
Use 'file'/'sname' fields MAY MAY MUST NOT
DHCP message type DHCPOFFER DHCPACK DHCPNAK
Parameter request list MUST NOT MUST NOT MUST NOT
Message SHOULD SHOULD SHOULD
Client identifier MUST NOT MUST NOT MAY
Vendor class identifier MAY MAY MAY
Server identifier MUST MUST MUST
Maximum message size MUST NOT MUST NOT MUST NOT
All others MAY MAY MUST NOT

[_china]

有最后一项options的详细资料吗?比如这个options项:
63 82 53 63 35 01 03 .... FF
可以说明一下吗? 谢谢.

[shakira008]

mark

[_china]

耐心地等待高人光临指教...

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