BGP Policies Conflicting with Internal Defaults

Depending on the physical topology of an AS and how BGP policies are set, some nonoptimal situations might arise. For instance, traffic inside the AS following IGP defaults to reach a BGP border router might loop if the BGP border routers have contradictory BGP policies that result in the traffic's being sent back inside the AS.

Tip

See the section Policy Routing in Chapter 12.

This section discusses situations in which loops might occur and experiments with possible solutions to the problems. The following two cases will be considered:

  • Defaults inside the AS in conjunction with a primary/backup BGP policy

  • Defaults inside the AS in conjunction with other BGP policies

Defaults Inside ...

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