bfd not working

[DraganSkundric87318]

hi,

I am testing BFD protocol, configure it on interface but I do not see router generates or responds to other party BFD messages. Do I have to connect it to my routing protocol in order to start working? I wanted to test it first without configuring routing to use it.

br

[Torbjørn · Accepted solution]

Yes, you need to configure a protocol to register to the BFD service. 

The simplest way to do this is probably to configure static routes with BFD:

! Configure BFD for the interface
interface {egress interface}
 bfd interval 500 min_rx 500 multiplier 5

! Create static route and register with BFD
ip route {destination} {destination mask} {next hop} {egress interface}
ip route static bfd {egress interface} {next hop}

 Once you have configured this on both ends you should be able to see the session as "up" when running "show bfd summary"

The docs aren't great, but you can read more about BFD here: https://www.cisco.com/c/en/us/td/docs/routers/ios/config/17-x/ip-routing/b-ip-routing/m_irb-bi-fwd-det-0.html  

[M02@rt37 · Accepted solution]

hello @DraganSkundric87318 

yes you need to configure BDF attached with your routing protocol. Which routing protocol?

Check here please you use case:

https://www.cisco.com/c/en/us/td/docs/ios/12_0s/feature/guide/fs_bfd.html

[David Ruess · Accepted solution]

Hello,

BFD should be attached to something that will utilize it for it to register. It doesn't have to be a routing protocol specifically as other protocols can use it such as HSRP, Multicast (PIM), and DMVPN.

For further context you can reference this document and see teh section on Prerequisites:

https://www.cisco.com/c/en/us/td/docs/ios/12_0s/feature/guide/fs_bfd.html#wp1027195

Prerequisites:

-Cisco Express Forwarding (CEF) and IP routing must be enabled on all participating routers.

-You must enable Cisco Parallel eXpress Forwarding (PXF) on the Cisco 10720 Internet router in order for BFD to operate properly. PXF is enabled by default and is generally not turned off.

-One of the IP routing protocols supported by BFD must be configured on the routers before BFD is deployed. You should implement fast convergence for the routing protocol that you are using.....

-David

[DraganSkundric87318]

hi,

my bfd session is ok after connecting it to bgp, but ..

sh bfd drop shows me BFD Not Configured ipv4 drops an is increasing. Any ideas?

br

[MHM Cisco World]

Make new post it better 

Thanks 

MHM

[DraganSkundric87318]

hi,

I've solved these drops. I have two eBgp peers, each is reachable on different interface. Firstly I implemented BFD only on one interface and for one peer. BFD works ok but I saw these drops. After i implemented BFD for second peer on second interface, drops are gone. Strange.