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15 Cards in this Set
- Front
- Back
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what is the private AS range for 16bit asn. |
64512-65535 |
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How does bgp do loop prevention for external routes |
Examines AS_PATH attribute and checks to see it sees our |
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What is a Well Known - Mandatory mean: |
*** BGP Attribute Description *** Well-Known = Must be supported by BGP Mandatory = MUST be included in an update are BGP will throw error.
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3 examples of Well-Known Mandatory attributes |
ORIGIN NEXT_HOP AS_PATH |
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What does "Well-Known, Discretionary" mean in BGP terms |
*** Attribute Characteristic **
Well-Known = MUST be supported by stack. Discrectionary = May or May not be advertised in the update. |
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What does "Optional, Transitive" mean in BGP terms: |
Optional = May or may not be supported by the implementation.
Transitive = Should be sent to should be passed onto next AS regardless. |
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What does "Optional, Non-Transitive" mean in BGP terms: |
Optional = May or may not be supported by implementation.
Non-Transitive = No requirements to pass along and can be safely ignored. |
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What does Cisco call the MED in IOS? |
METRIC
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Which MED will win? lower or higher? |
Lower! |
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What protocol/port does BGP use for peering session |
TCP 179 |
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What needs to be true to make MED relevant? |
Peering session with the same AS.
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Why RFC 1997 |
Defines well known BGP communities that operators should support. |
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What does this mean: RFC 1997 --> NO_EXPORT |
Receiving AS should not advertise the route outside its confederation (if applicable) or it self. |
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What does this mean: RFC 1997 --> NO_ADVERTISE |
All routes received carrying a communities attribute containing this value MUST NOT be advertised to other BGP ******* PEERS ******** |
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What does this mean:
RFC 1997 --> NO_EXPOR_SUBCONFED |
All routes received carrying a communities attribute containing this value MUST NOT be advertised to ebgp (external peers) including members autonomous systems inside a confederation) |
