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BGP ASNs

netutils.asn

Functions for working with BGP ASNs.

asn_to_int(asplain)

Convert AS Number to standardized asplain notation as an integer.

Parameters:

Name Type Description Default
asplain str

An asplain notated BGP ASN with community.

 required

Returns:

Type Description
int

Integer value within of the given asplain value provided.

Examples:

>>> from netutils.asn import asn_to_int
>>> asn_to_int("65000")
65000
>>> asn_to_int("65000.111")
4259840111
>>>
Source code in netutils/asn.py 
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def asn_to_int(asplain: str) -> int:
    """Convert AS Number to standardized asplain notation as an integer.

    Args:
        asplain: An `asplain` notated BGP ASN with community.

    Returns:
        Integer value within of the given asplain value provided.

    Examples:
        >>> from netutils.asn import asn_to_int
        >>> asn_to_int("65000")
        65000
        >>> asn_to_int("65000.111")
        4259840111
        >>>
    """
    # ASN is in asdot notation
    if "." in asplain:
        asn_list = asplain.split(".")
        asn = int(f"{int(asn_list[0]):016b}{int(asn_list[1]):016b}", 2)
        return asn
    return int(asplain)

int_to_asdot(asn_int)

Convert integer to standardized asdot notation for BGP ASN.

Parameters:

Name Type Description Default
asn_int int

Integer value of the BGP ASN.

 required

Returns:

Type Description
str

asdot notated BGP ASN as a string.

Examples:

>>> from netutils.asn import int_to_asdot
>>> int_to_asdot(65000)
'65000'
>>> int_to_asdot(4259840111)
'65000.111'
>>>
Source code in netutils/asn.py 
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def int_to_asdot(asn_int: int) -> str:
    """Convert integer to standardized asdot notation for BGP ASN.

    Args:
        asn_int: Integer value of the BGP ASN.

    Returns:
        `asdot` notated BGP ASN as a string.

    Examples:
        >>> from netutils.asn import int_to_asdot
        >>> int_to_asdot(65000)
        '65000'
        >>> int_to_asdot(4259840111)
        '65000.111'
        >>>
    """
    if isinstance(asn_int, str):
        asn_int = int(asn_int)
    if asn_int > 2**32 - 1 or asn_int < 1:
        raise ValueError(f"`{str(asn_int)}` is not within range of 1 - 2^32-1")
    if asn_int >= 2**16:
        asn1 = asn_int >> 16
        asn2 = asn_int & ((1 << 16) - 1)
        return f"{asn1}.{asn2}"
    return str(asn_int)