[AF] BGP peer cannot learn local Layer 3

Problem Description

When the local end and the remote end start BGP, the local end can learn the remote end's Layer 3, but the remote end cannot learn the local end's Layer 3

Warning Info

Effective troubleshooting steps

1. Check the configuration and find no abnormalities. The neighbor status is also established normally.
2. Capture packets, delete BGP neighbors and then add them back, thereby triggering message interaction, and capture packets for analysis
3. Analyzing the data packets, we found that the other end announced that it had sent an UPDATE MESSAGE, but our end did not send one.
4. Further checking of the AF configuration revealed that the running Network Segment configured in BGP is 10.11.0.0/16, while the one in the Layer 3 table is 10.11.0.0/24, that is, the Network Segment configured in BGP does not Sensitive in the Layer 3 table. R&D said that the new architecture has been verified for this situation. If the Network Segment configured in BGP does not Sensitive in the Layer 3 table, the relevant UPDATE MESSAGE will not be sent.

Root cause

The new architecture has a check for this situation. If the Network Segment configured in BGP does not Sensitive in the Layer 3 table, the relevant UPDATE MESSAGE will not be sent.

solution

Correct the configuration so that the Network Segment configured by BGP also Sensitive in the Layer 3 table

Original Link

https://support.sangfor.com.cn/cases/list?product_id=13&type=1&category_id=23199&isOpen=true