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Notes:
In this example, AS1 forces AS3 to send the packets towards 10.0.0.0/8 on the R31-R11 link and the packets towards 11.0.0.0/8 on the R32-R12 link. This is a common method used to balance traffic over external links, but an important drawback is that if the R11-R31 link fails, AS3 would not be able to utilize the R12-R32 link to reach 10.0.0.0/8 and would be forced to used the path through AS2.
Note that if R12 advertised 10.0.0.0/7 instead of advertising both 10.0.0.0/8 and 11.0.0.0/8, then, most of the traffic could be received via AS3 since AS3 is advertising a more specific prefix (see later).