03-28-2014 10:11 AM - edited 03-04-2019 10:40 PM
Can anyone help clarify if Bidirectional Forwarding Detection (BFD) is compatible with eBGP multihop? It seems it wouldn't naturally because the physical links are no longer associated with the BGP peer, but I found a document that suggests they can be used together. Is anyone aware of the twon being used or any documentation that clarifies it further?
thank you,
Bill
Solved! Go to Solution.
03-28-2014 02:15 PM
Bill
Page 11 of this NANOG presentation does talk about BFD and EBGP.
https://www.nanog.org/meetings/nanog45/presentations/Monday/Scholl_BFD_N45.pdf
Also RFC 5882 explicitly discusses using BFD with EBGP.
http://tools.ietf.org/html/rfc5882
HTH
Rick
03-28-2014 02:15 PM
Bill
Page 11 of this NANOG presentation does talk about BFD and EBGP.
https://www.nanog.org/meetings/nanog45/presentations/Monday/Scholl_BFD_N45.pdf
Also RFC 5882 explicitly discusses using BFD with EBGP.
http://tools.ietf.org/html/rfc5882
HTH
Rick
03-31-2014 06:54 AM
I seem to keep finding contradictions on the support. The RFC states its support, but it looks like it may come down to vendor and OS version.
This states it's not supported on the ASR1000
http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/iproute_bgp/configuration/xe-3s/asr1000/irg-xe-3s-asr1000-book/irg-sup-for-bfd.html#GUID-F4FF8AFE-4DA4-441B-967C-2ABE75450B87
"BFD works only for directly-connected neighbors. BFD neighbors must be no more than one IP hop away. Multihop configurations are not supported. "
but it is on the ASR 901
http://www.cisco.com/c/en/us/td/docs/wireless/asr_901/Configuration/Guide/config_guide/multihopbfd.html#wp1087195
and Juniper seems to support it
http://www.juniper.net/techpubs/en_US/junos12.1/topics/topic-map/bgp-bfd.html
03-31-2014 07:15 AM
Bill
It does not surprise me that there are inconsistencies in support for this new feature and that it does come down to vendor and OS version. Your original question was whether BFD is compatible with EBGP multihop. And the answer for now seems to be "sometimes it is". But we will need to read release notes carefully to determine whether a particular platform and version of OS do support it.
HTH
Rick
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