BGP: Difference between revisions
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neighbor 4.4.4.4 peer-group IBGP_PEERS |
neighbor 4.4.4.4 peer-group IBGP_PEERS |
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= MED vs Local Preference = |
= MED vs Local Preference vs Weight = |
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;Multi-Exit Discriminator |
;Multi-Exit Discriminator |
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*Routers within the local AS are told what path to use to exit that AS. |
*Routers within the local AS are told what path to use to exit that AS. |
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*The local preference value is passed only among iBGP peers, and this value never leaves the local AS. |
*The local preference value is passed only among iBGP peers, and this value never leaves the local AS. |
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*Weight is configured for Outgoing direction: |
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[R1]-------[R2] |
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| |
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|--------[R3] |
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If you want R1 to prefer R3, Configure more weight on R1 |
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Configured on Per-Neighbor basis. |
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* Local Preference is configured in Incoming direction. |
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Configure Local Pref R3 so that R1 will prefer routes learned via R3. |
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Local Pref stays inside AS only(use MED if you want to affect AS also). |
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Configured for the whole BGP process on the router. |
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;Weight: |
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Cisco Proprietary |
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;Example |
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<--AS3--> <--AS100--> |
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|------[R2]--------[R4] |
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[R1] | |
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|------[R3]--------[R5] |
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Weight R1 to R2 or R3: |
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|------> |
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Local Preference R2 to R1 or R3 to R1: |
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<------| |
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MED R4 to R2 or R5 to R3: |
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|---------> |
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<br /> |
<br /> |