In the original BGP configuration, it needs to specify a peer IPv4 address to establish peer connections.
For CLOS deployment in the data center, the IP interfaces grow dramatically due to the full connection between spines and LEAFs.
(each peer connection needs IPv4 addresses on it). To eliminate this situation, we need the unnumbered interface to establish peer connections.
- "BGP unnumbered" support for Layer 3 interfaces that bind IP on a port or port-channel interface.
- Switch model name:
AS7726-32X, AS7326-56X, AS7816-64X, AS5835-54X(T), AS4630-54PE, AS9716-32D, AS8000(Minipack), Wedge100BF-32X
- Edgecore SONiC version:
Establish BGP unnumbered session
Step 1. Initialize FRR configuration. Please refer to FRRouting and config initialization tutorial.
Step 2. Configure IP address properly for BGP session. Please refer to Management and front port IPv4/IPv6 Address tutorial.
Step 3. Enter Vty shell.
"vtysh" provides a combined frontend to all FRR daemons in a single combined session.
Step 4. Configuring BGP Neighbor Session with unnumbered. Replaces the IP configuration of the original neighbor with the locally connected interface. (refer to Establish BGP session)
The AS number of neighbors, you could assign the AS number of neighbors. The "external" is to eBGP and the "internal" is to iBGP.
sonic(config-router)# neighbor Ethernet8 interface remote-as external
sonic(config-router)# neighbor Ethernet8 interface remote-as internal
Step 5. Checking the BGP connection and neighbor status.
On the AS7726-32X (Switch1)
On the AS5835-54X (Switch2)
Step 6. Save the routing setting.