BGP: Customer network announcing error (not advertised)

Question

Hi to all.
Our company - is small business ISP. We have two BGP upstreams, and some customers who connect with us via BGP. Day ago, our customer opened a case that we don't announce his network to the "global network". I can see, that he announce me his network, and BGP add this prefix to the routing table. But when i open prefix detail - i see that prefix not advertised to any peer.
Here is sh run :
router bgp xxx
bgp router-id xx.xx.xx.xx
bgp log-neighbor-changes
neighbor xx.xx.xx.xx remote-as xxxx
neighbor xx.xx.xx.xx description Customer
neighbor yy.yy.yy.yy remote-as yyyy
neighbor yy.yy.yy.yy description Uplink
address-family ipv4
  neighbor xx.xx.xx.xx activate
  neighbor xx.xx.xx.xx default-originate
  neighbor xx.xx.xx.xx soft-reconfiguration inbound
  neighbor xx.xx.xx.xx prefix-list DEFAULT out
  neighbor xx.xx.xx.xx prefix-list Deny-Default in
neighbor yy.yy.yy.yy activate
  neighbor yy.yy.yy.yy prefix-list BizTel out
  neighbor yy.yy.yy.yy filter-list 1 out
exit-address-family
ip as-path access-list 1 permit ^$
ip as-path access-list 1 permit ^xxxx$
ip prefix-list DEFAULT seq 5 permit 0.0.0.0/0
ip prefix-list Deny-Default seq 10 deny 0.0.0.0/32
ip prefix-list Deny-Default seq 15 permit 0.0.0.0/0 le 32
sh ip bgp neighbors xx.xx.xx.xx received-routes:
   Network          Next Hop            Metric LocPrf Weight Path
*> 0.0.0.0          xx.xx.xx.xx                         0 xxxx xxxx yyyy i
*> zz.zz.zz.zz/24    xx.xx.xx.xx           0             0 xxxx xxxx i
sh ip bgp neigh xx.xx.xx.xx adv routes:
   Network          Next Hop            Metric LocPrf Weight Path
*> 0.0.0.0          xx.xx.xx.xx                         0 xxxx xxxx yyyy i
sh ip bgp  zz.zz.zz.zz /24:
BGP routing table entry for zz.zz.zz.zz/24, version 6503140
Paths: (3 available, best #1, table default)
  Not advertised to any peer
  xxxx xxxx, (received & used)
    xx.xx.xx.xx from xx.xx.xx.xx (cc.cc.cc.cc)
      Origin IGP, metric 0, localpref 100, valid, external, best
Can somebody help me with this question?

Answer 1

The outputs are very confusing ie.
sh ip bgp neighbors xx.xx.xx.xx received-routes:
   Network          Next Hop            Metric LocPrf Weight Path
*> 0.0.0.0          xx.xx.xx.xx                         0 xxxx xxxx yyyy i
*> zz.zz.zz.zz/24    xx.xx.xx.xx           0             0 xxxx xxxx i
presumably these are the routes received from the customer ?  If so -
1) why are you receiving a default from the customer with yyyy in the AS PATH ?
2) why are there two instances of xxxx in AS PATH for both routes in the AS PATH ?
also -
sh ip bgp neigh xx.xx.xx.xx adv routes:
   Network          Next Hop            Metric LocPrf Weight Path
*> 0.0.0.0          xx.xx.xx.xx                         0 xxxx xxxx yyyy i
if you are looking at routes advertised upstream why are you looking at advertised routes to the customer ?
It is difficult to say what is happening because you have blanked out all the information.
Finally you have -
neighbor yy.yy.yy.yy prefix-list BizTel out
but there is no such prefix list in the config you posted
Can you clarify by answering the above and perhaps explain how this is all setup ie. is x.x.x.x the customer and y.y.y.y your upstream provider.
The more information you can give the more we can help.
Jon