I have a 1072 in an IXP and I am observing an erroneous behavior when selecting BGP routes.

All use the same preferences and the same filters, so it is ruled out that this is the origin of the problems.

These are some examples (there are many):

Ex1:
0 ADb dst-address=AAA.BBB.168.0/21 gateway=CCC.DDD.1.82 gateway-status=CCC.DDD.1.82 reachable via SFP1 distance=20 scope=40 target-scope=10 bgp-as-path="AS1,AS2" bgp-local-pref=150 bgp-origin=igp received-from=ISP1

1 Db dst-address=AAA.BBB.168.0/21 gateway=CCC.DDD.1.106 gateway-status=CCC.DDD.1.106 reachable via SFP1 distance=20 scope=40 target-scope=10 bgp-as-path="AS2" bgp-local-pref=150 bgp-med=0 bgp-origin=igp received-from=ISP2


Ex2:
0 ADb dst-address=176.YYY.XXX.0/21 gateway=ZZZ.EEE.1.17 gateway-status=ZZZ.EEE.1.17 reachable via SFP1 distance=20 scope=40 target-scope=10 bgp-as-path="AS1,AS2,AS3,AS4,AS5,AS6,AS7" bgp-local-pref=150 bgp-origin=igp received-from=ISP1

1 Db dst-address=176.YYY.XXX.0/21 gateway=ZZZ.EEE.1.106 gateway-status=ZZZ.EEE.1.106 reachable via SFP1 distance=20 scope=40 target-scope=10 bgp-as-path="AS8,AS9,AS10,AS7" bgp-local-pref=150 bgp-origin=igp received-from=ISP2

I feel this whole post if out of context.

Post your routing filters (using proper export: /routing filters export - not just print).

And describe your problem more accurately.
What do you expect to happen, and what actually happens.

Fixed.

Ignore-as-path-len it's enable in my instance.

I saw before posting https://wiki.mikrotik.com/wiki/Manual:B ... _Algorithm , but NO SEE EXCEPTION

Sorry.

By default ignore-as-path-len it's enable in instance.

ignore-as-path length is not enabled by default.

It's true.