[c-nsp] Typical BGP operational policies

[Church, Charles]

Hey all,
 
    I support a small network, with own ASN.  They use address space
given by provider A, and are dual homed to providers A and B.  We take
full routes from each, and announce that address space (a /23) to both.
In looking at a variety of looking glass sites out there, I see most
only see that network via provider A's AS.  One I found did see it via
provider B only.  Is filtering being done by provider B outbound to it's
peers the only explanation for this (or the most likely one)?  One
particular looking glass didn't have a path to us via provider B, yet
does see our serial interface address (last hop that's still part of
provider B AS) as reachable via provider B.  For what it's worth,
address space is 75.77.38.0/23, ASN is 26296.  Provider A is 11456, B is
6389.  Just wondering if there is a real issue here, or if this partial
reachability depending on where you are is normal...
 
Thanks in advance,
 
Chuck