BGP - Allowas-in with number of occurrences

I ran into this BGP issue on IPexpert volume 2 Lab 4 today. Cat 1 is in AS 500. There are 3 other ASes, but CAT1 needs to see all of these as AS8888. Confederations right? For 2 of the ASes that is right, but the task says NOT to use a sub-as for AS78. Here is the AS map:

As500----As100----AS2456====AS78

AS2456 has 2 connections (R5 and R6) to AS78 (R7).

On R5 and R6 I have this ( I am allowed to use confederations on AS 2456):

router bgp 2456
bgp confederation identifier 8888
neighbor 150.20.56.7 remote-as 8888

on R7 I have this:

router bgp 78
neighbor 150.20.56.5 remote-as 8888
neighbor 150.20.56.5 local-as 8888
neighbor 150.20.56.5 allowas-in
neighbor 150.20.56.6 remote-as 8888
neighbor 150.20.56.6 local-as 8888
neighbor 150.20.56.6 allowas-in

Works great so far:

R7#show ip bgp sum | be Neigh
Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd
150.10.8.8 4 78 55 64 64 0 0 00:35:46 1
150.20.56.5 4 8888 112 121 64 0 0 00:01:07 5
150.20.56.6 4 8888 109 116 64 0 0 00:01:10 5

But notice the prefix I am learning from R8 (ibgp peer with R7). That prefix does not get installed by R5 and R6 because it has AS 8888 in the path. Here is the debug from R6:

R6#debug ip bgp update
*Oct 18 17:46:11.270: BGP(0): 150.20.56.7 rcv UPDATE about 200.200.200.0/24 -- DENIED
R6(config-rout due to: AS-PATH contains our own AS;

How do we allow R6 and R5 to accept this route? By using "allowas-in" option of the neighbor command. However, because we don't want R6 to learn routes that passed from R5 to R7 we set a maximum on the number of occurrences of the AS, which is 1.

R5 and R6:

router bgp 2456
neighbor 150.20.56.7 allowas-in 1

Now here is the same debug on R6:

*Oct 18 17:56:48.366: BGP(0): Revise route installing 1 of 1 routes for 200.200.200.0/24 -> 150.20.56.7(main) to main IP table

Let's take a look at CAT1 in AS 500

Cat1#show ip bgp | begin Net

Network Next Hop Metric LocPrf Weight Path
*> 200.200.200.0 150.20.110.1 0 8888 8888 78 ?

This is not good! We can get rid of AS 78 by doing this on R7:

R7(config)#router bgp 78
R7(config-router)#neighbor 150.20.56.5 local-as 8888 no-prepend replace-as
R7(config-router)#neighbor 150.20.56.6 local-as 8888 no-prepend replace-as

Now let's take a look:

Cat1#show ip bgp | beg Net

Network Next Hop Metric LocPrf Weight Path
*> 200.200.200.0 150.20.110.1 0 8888 8888 ?