dhcpkit.ipv6.extensions.pd_exclude module¶
Implementation of the DHCPv6-PD-Exclude option as specified in RFC 4833.
-
class
dhcpkit.ipv6.extensions.pd_exclude.PDExcludeOption(prefix_length: int = 64, subnet_id: bytes = None)[source]¶ Bases:
dhcpkit.ipv6.options.Option0 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | OPTION_PD_EXCLUDE | option-len | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | prefix-len | IPv6 subnet ID (1 to 16 octets) ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Prefix Exclude Option- option-code:
- OPTION_PD_EXCLUDE (67).
- option-len:
- 1 + length of IPv6 subnet ID in octets. A valid option-len is between 2 and 17.
- prefix-len:
- The length of the excluded prefix in bits. The prefix-len MUST be between ‘OPTION_IAPREFIX prefix-length’+1 and 128.
- IPv6 subnet ID:
- A variable-length IPv6 subnet ID up to 128 bits.
The IPv6 subnet ID contains prefix-len minus ‘OPTION_IAPREFIX prefix- length’ bits extracted from the excluded prefix starting from the bit position ‘OPTION_IAPREFIX prefix-length’. The extracted subnet ID MUST be left-shifted to start from a full octet boundary, i.e., left- shift of ‘OPTION_IAPREFIX prefix-length’ mod 8 bits. The subnet ID MUST be zero-padded to the next full octet boundary.
-
load_from(buffer: bytes, offset: int = 0, length: int = None) → int[source]¶ Load the internal state of this object from the given buffer. The buffer may contain more data after the structured element is parsed. This data is ignored.
Parameters: - buffer – The buffer to read data from
- offset – The offset in the buffer where to start reading
- length – The amount of data we are allowed to read from the buffer
Returns: The number of bytes used from the buffer
-
option_type= 67¶