no it isn't and as a side note as most routers support route refresh you should be better doing a clear ip bgp x.x.x.x in or
clear ip bgp x.x.x.x out which are soft resets which don't tear the peering.
I'm not able to find subnetwork 10.10.1.20/30 with command below:
10.10.10.1> sh ip bgp neigh 10.10.1.2 routes
Also this command doesn't show route 10.10.1.20/30
10.10.1.1> sh ip bgp neigh 10.10.1.2 advertised-routes
Can see 10.10.1.20/30 in below
10.10.1.1>sh ip bgp
Can't see 10.10.1.20/30 in below
10.10.10.1>sh ip bgp
What should I within clear ip bgp? or any other usefull command? Any glue?
clear ip bgp is not mandatory the only the important thing is the mask in the network statment and in the routing table should be same.
aren't you filtering the prefixes advertised to 10.10.1.2?
Outgoing route-map, filter-list, etc.?
You could try
clear ip bgp 10.10.1.2 soft
but it should not be necessary if the 10.10.1.20/30 was in the RIB at the moment you added
network 10.10.1.20 mask 255.255.255.252
to you BGP config.
Another low probability chance:
Aren't you receiving the same prefix from 10.10.1.2 already with better BGP attributes?
In that way you would not advertise the prefix back.
Or isn't the prefix next-hop pointing to 10.10.1.2?
10.10.1.20 is directly connected network on RouterID 10.10.1.1
I don't think that I should add this route into IGP, as we use eBGP between RouterID 10.10.1.1 and RouterID 10.10.10.1