The stack type for this interconnect attachment to identify whether
the IPv6 feature is enabled or not. If not specified, IPV4_ONLY will
be used. This field can be both set at interconnect attachments
creation and update interconnect attachment operations.
Values:
UNDEFINED_STACK_TYPE (0):
A value indicating that the enum field is not
set.
IPV4_IPV6 (22197249):
The interconnect attachment can have both
IPv4 and IPv6 addresses.
IPV4_ONLY (22373798):
The interconnect attachment will only be
assigned IPv4 addresses.