Nbns-List - HP 6125XLG Command Reference Manual

offset offset: Specifies the offset to match the option, in the range of 0 to 254 bytes. If the offset argument
is not specified, the server matches the entire option with the rule.
length length: Matches the specified length of the option, in the range of 1 to 128 bytes. The specified
length must be the same as the hex-string length.
Usage guidelines
You can configure multiple match rules for a DHCP the user class.
The DHCP server matches DHCP requests against the match rules. A DHCP client matches the DHCP user
class as long as it matches one of the specified rules.
The match operation follows these guidelines:
• If only the option-code argument is specified in the rule, packets containing the option match the
rule.
If only the option-code and hex-string arguments are specified in the rule, packets that have the
•
specified hex string in the specified option match the rule.
If the option-code, hex-string, offset and length arguments are specified in the rule, packets match
•
the rule as long as their content from offset+1 bit to offset+length bit in the specified option is the
same as the specified hex string.
If the option-code, hex-string, and mask arguments are specified in the rule, the DHCP server ANDs
•
the content from the first bit to the mask- 1 bit in the specified option with the mask, and then
compares the result with the result of the AND operation between hex-string and mask. If the two
results are the same, the received packet matches the rule.
The option-code specified by different if-match option commands can be the same.
Examples
# Specify that packets containing Option 82 match the DHCP user class contain-option82.
<Sysname> system-view
[Sysname] dhcp server class contain-option82
[Sysname-dhcp-class-contain-option82] if-match option 82
# Specify that packets containing Option 82 whose first three bytes is 0x13ae92 match the DHCP user
class exam.
<Sysname> system-view
[Sysname] dhcp server class exam
[Sysname-dhcp-class-exam] if-match option 82 hex 13ae92 offset 0 length 3
# Specify that packets containing Option 82 whose highest bit of the fourth byte is 1 match the DHCP
user class exam.
<Sysname> system-view
[Sysname] dhcp class exam
[Sysname-dhcp-class-exam] if-match option 82 hex 00000080 mask 00000080
Related commands
dhcp class

nbns-list

Use nbns-list to specify WINS server addresses in a DHCP address pool.
Use undo nbns-list to remove the specified WINS server addresses.
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