Hello,
I finally managed to DISCARD AS-PATH containing private AS with rules behind.
They are directly taken from Cisco's examples here
http://as2914.net/bogon_asns/configuration_examples.txt
This will create a bogons-asn filter that could be used with upsteams and peers to filter those buggy routes (a few Tier1 already filter those routes, you can safely consider them as buggy).
add action=accept bgp-as-path=_0_ chain=bogons-asn
add action=accept bgp-as-path=_23456_ chain=bogons-asn
add action=accept bgp-as-path="_(6449[6-9])_|_(6450[0-9])_|_(6451[0-1])_|_(655\
3[6-9])_|_(6554[0-9])_|_(6555[0-1])_" chain=bogons-asn
add action=accept bgp-as-path="_6(4(5(1[2-9]|[2-9][0-9])|[6-9][0-9][0-9])|5([0\
-4][0-9][0-9]|5([0-2][0-9]|3[0-5])))_" chain=bogons-asn
add action=accept bgp-as-path=\
"_6555[2-9]_|_655[6-9][0-9]_|_65[6-9][0-9][0-9]_|_6[6-9][0-9][0-9][0-9]_" \
chain=bogons-asn
add action=accept bgp-as-path="_[7-9][0-9][0-9][0-9][0-9]_|_1[0-2][0-9][0-9][0\
-9][0-9]_|_130[0-9][0-9][0-9]_" chain=bogons-asn
add action=accept bgp-as-path="_1310[0-6][0-9]_|_13107[0-1]_" chain=\
bogons-asn
add action=accept bgp-as-path="_42[0-8][0-9][0-9][0-9][0-9][0-9][0-9][0-9]_" \
chain=bogons-asn
add action=accept bgp-as-path="_(429[0-3][0-9][0-9][0-9][0-9][0-9][0-9])_|_(42\
94[0-8][0-9][0-9][0-9][0-9][0-9])_" chain=bogons-asn
add action=accept bgp-as-path=\
"_(42949[0-5][0-9][0-9][0-9][0-9])_|_(429496[0-6][0-9][0-9][0-9])_" \
chain=bogons-asn
add action=accept bgp-as-path=\
"_(4294967[0-1][0-9][0-9])_|_(42949672[0-8][0-9])_|_(429496729[0-4])_" \
chain=bogons-asn