BGP neighbor states
BGP forms a TCP session with neighbor routers called peers. The BGP session may report in the following states:
State |
Listen for TCP? |
Initiate TCP? |
TCP Up? |
Open Sent? |
Open Received? |
Neighbor Up? |
Idle |
No |
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Connect |
Yes |
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Active |
Yes |
Yes |
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Open sent |
Yes |
Yes |
Yes |
Yes |
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Open confirm |
Yes |
Yes |
Yes |
Yes |
Yes |
|
Established |
Yes |
Yes |
Yes |
Yes |
Yes |
Yes |