Nth a little biased

RouterOS General
1

I am trying some load balance with src address lists:

 1   ;;; Enrutar
     chain=prerouting src-address-list=clientes dst-address-list=!internas action=jump jump-target=enrutar 
 2   chain=enrutar src-address-list=ruta2 action=return 
 3   chain=enrutar src-address-list=ruta3 action=return 
 4   chain=enrutar nth=1,3,0 action=add-src-to-address-list address-list=ruta2 address-list-timeout=1d 
 5   chain=enrutar src-address-list=ruta2 action=return 
 6   chain=enrutar nth=1,3,1 action=add-src-to-address-list address-list=ruta3 address-list-timeout=1d

When I test it seems to work, but if i leave it some time (minutes, hours, days) it starts doing nth balancing wrong:

Rule 4 and 5 have 522 packet count, while rule 6 has only 98.
If i browse address list i find that address list ruta2 has many more addresses than ruta3. I have tried resetting counters and rebooting mt, and always first rule has more packet count than second rule (but ratio varies).

Verified on 2.9.9 and 2.9.19, with hotspot active.

2

why with these weird versions?

3

It was the respective latest version of routeros when we updated them. I didn’t know those were weird versions.

We also have this on 2.9.24, same behaviour.

4

no, i mean you are 10 versions behind. you should consider upgrading

5

I found a trick.

I created 2 set of rules:

  • one of them just like the ones i posted before
  • the other does the same but in opposite order (first adds to listaB, second to listaA). When i follow these rules they bias in favour of listaB.

I made a timer so each 5 minutes i switch over one or other rules, so each 5 minutes bias direction changes. It works quite fine in the long term (about 100 addresses balanced with an average bias below 5%).