12-17-2013 12:00 AM - edited 03-04-2019 09:53 PM
Hi guys, see the attached diagram for these question:
What routers will receive udpates originated on the routers below supposing each node has default BGP configurations (and no sync enabled)?
Is the below correct?
Route A:
Route C:
Route E:
Route H:
Thank you.
Solved! Go to Solution.
12-17-2013 06:04 AM
Hi Todd,
In that case:
Route originated on A: Received by C only, not forwarded further
Route originated on C: Received by A, D, E, forwarded from E to H, from H to I, from I to J and F but F will drop it (AS_PATH), from J to K, from K to G but G will drop it (AS_PATH). Resulting set: A, D, E, H, I, J, K
Route originated on E: Received by C and H, forwarded from H to I, from I to J and F but F will drop it (AS_PATH), from J to K, from K to G but G will drop it (AS_PATH). Resulting set: C, H, I, J, K
Route originated on H: Received by E and I, forwarded from E to C and from I to F, forwarded from F to D, forwarded from I to J, from J to K, from K to G, from G to D. Resulting set: E, I, C, F, D, J, K, G
Best regards,
Peter
12-17-2013 12:36 AM
Hi Todd,
In your exhibit, the links interconnecting the routers are physical links or BGP peerings? In other words, how are the BGP adjacencies configured - which routers are BGP peers and which are not? This is crucial to answer your question correctly.
Best regards,
Peter
12-17-2013 05:48 AM
All interlinks are one hop BGP peerings.
12-17-2013 06:04 AM
Hi Todd,
In that case:
Route originated on A: Received by C only, not forwarded further
Route originated on C: Received by A, D, E, forwarded from E to H, from H to I, from I to J and F but F will drop it (AS_PATH), from J to K, from K to G but G will drop it (AS_PATH). Resulting set: A, D, E, H, I, J, K
Route originated on E: Received by C and H, forwarded from H to I, from I to J and F but F will drop it (AS_PATH), from J to K, from K to G but G will drop it (AS_PATH). Resulting set: C, H, I, J, K
Route originated on H: Received by E and I, forwarded from E to C and from I to F, forwarded from F to D, forwarded from I to J, from J to K, from K to G, from G to D. Resulting set: E, I, C, F, D, J, K, G
Best regards,
Peter
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