Hello,
I have 2 edge routers, each connected to Provider1 and Provider2 and together as well.
I've turned on redistribute other bgp on all instance since i'm receiving BGP advertisement from a 3rd router of mine.
Sadly all Provider1's adveritsement got reflected onto Provider2 (and visible in the bgp advertisements) even if i set the following filters:
1) Prefix localnet1 - accept
2) prefix localnet2 - accept
3) prefix 0.0.0.0/0 - discard

i've also tried to:
4) bgp as path !LocalAS - discard
nor of the helped as expected - the last one filters the other provider's AS (good) but filtered mine prefixes (since locally advertised routers not contains LocalAS in the routing table)

I would be pleased for any help or idea to check, thanks!

ps: R1 running 5.14, R2 running 5.9

Hello,
I have 2 edge routers, each connected to Provider1 and Provider2 and together as well.
I've turned on redistribute other bgp on all instance since i'm receiving BGP advertisement from a 3rd router of mine.
Sadly all Provider1's adveritsement got reflected onto Provider2 (and visible in the bgp advertisements) even if i set the following filters:
1) Prefix localnet1 - accept
2) prefix localnet2 - accept
3) prefix 0.0.0.0/0 - discard

i've also tried to:
4) bgp as path !LocalAS - discard
nor of the helped as expected - the last one filters the other provider's AS (good) but filtered mine prefixes (since locally advertised routers not contains LocalAS in the routing table)

I would be pleased for any help or idea to check, thanks!

ps: R1 running 5.14, R2 running 5.9

try add your own prefixes. and do a default discard.

add action=discard chain=bgp-provider-out comment=default disabled=no invert-match=no set-bgp-prepend-path=""
add action=accept chain=bgp-our-prefixes disabled=no invert-match=no prefix=91.x.x.x/21 prefix-length=21 set-bgp-prepend-path=""
add action=accept chain=bgp-our-prefixes disabled=no invert-match=no prefix=91.x.x.x/23 prefix-length=23 set-bgp-prepend-path=""
add action=accept chain=bgp-our-prefixes disabled=no invert-match=no prefix=77.x.x.x/24 prefix-length=24 set-bgp-prepend-path=""
add action=accept chain=bgp-our-prefixes disabled=no invert-match=no prefix=77.x.x.x/23 prefix-length=23 set-bgp-prepend-path=""
add action=accept chain=bgp-our-prefixes disabled=no invert-match=no prefix=77.x.x.x/22 prefix-length=22 set-bgp-prepend-path=""
add action=accept chain=bgp-our-prefixes disabled=no invert-match=no prefix=77.x.x.x/22 prefix-length=22 set-bgp-prepend-path=""
add action=accept chain=bgp-ourprovider-in comment=default-route disabled=no invert-match=no prefix=0.0.0.0 prefix-length=0 set-bgp-prepend-path="" set-in-nexthop=\
xx.xx.xx.xx(yor peer ip)

that was my first.
i've already tried to:
-filter routes to provider1 what has provider2 in as path
-make a default discard filter-out in instances to provider than enable own routes in peer's filter-out

now the policy is discard on instance AND discard on peer's out filter, only one-one discard rule in the list, however a lot of advertisement visible to the peer
(tried on ROS5.4)

i figured out, that routing filter works on prefixes (catched the first prefix what coming from provider1 and refleted to provider2. make a filter on that, re-checked the advertisements - and voila, that one is not reflected).

However using empty prefix string or using 0.0.0.0/0 as prefix action=discard does NOT helped.
maybe there is a switch what disables maching on 0/0?

this is working for me.

hmm... which ROS version?
can you paste please the export of Your (masked) instance and peer configuration?