Hello,
I'm wondering if anyhow have faced issues/incompatibility in BFD setup with IP unnumbered feature on NX-OS.
My scenario has 2 N93108TC-EX switches (named R1, R2) running NX-OS rel. 7.0(3)I4(6).
The two switches are directly connected with a P2P L3 link (port Eth1/45, no switchport + subinterfaces). Interfaces and subinterfaces are configured with medium p2p, no ip redirects.
With the configuration below, the default routes are installed on R1 and R2 VRF BLUE routing tables and i can successfully cross ping the loopbacks.
R1 is configured with:
Interfaces
Lo1 - in VRF default, numbered interface (172.16.1.1/32)
Lo10 - in VRF BLUE, simulates clients (192.168.1.1/24)
Eth1/45.10 - in VRF BLUE, unnumbered interfaces that uses Lo1 IP address
Static routes
ip route 172.16.1.2/32 Eth1/45.10 172.16.1.2
ip route 0.0.0.0/0 Eth1/45.10 172.16.1.2
R2 is configured with:
Interfaces
Lo1 - in VRF default, numbered interface (172.16.1.2/32)
Lo10 - in VRF BLUE, simulates clients (192.168.2.1/24)
Eth1/45.10 - in VRF BLUE, unnumbered interfaces that uses Lo1 IP address
Static routes
ip route 172.16.1.1/32 Eth1/45.10 172.16.1.1
ip route 0.0.0.0/0 Eth1/45.10 172.16.1.1
Enabling BFD feature on both R1, R2 adding the commands:
on R1 ip route static bfd interface Eth1/45.10 172.16.1.2
on R2 ip route static bfd interface Eth1/45.10 172.16.1.1
The default routes on both R1 and R2 are removed from VRF BLUE routing tables and ping fails.
sh bfd neighbor command returns nothing either on R1 and R2
If i assign IP addresses (/30 P2P) to subinterfaces instead of leveraging on ip unnumbered, BFD works properly.
Here below the official docs i'm following for configuration:
IP unnumbered - https://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus9000/sw/7-x/interfaces/configuration/guide/b_Cisco_Nexus_9000_Series_NX-OS_Interfaces_Configuration_Guide_7x/b_Cisco_Nexus_9000_Series_NX-OS_Interfaces_Configuration_Guide_7x_chapter_0101...
Static Routing - https://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus9000/sw/6-x/unicast/configuration/guide/l3_cli_nxos/l3_route.html
BFD - https://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus9000/sw/6-x/interfaces/configuration/guide/b_Cisco_Nexus_9000_Series_NX-OS_Interfaces_Configuration_Guide/b_Cisco_Nexus_9000_Series_NX-OS_Interfaces_Configuration_Guide_chapter_0101.html#...)
Grazie, ciao
Fabrizio
