Tag: BFD

IOSXR – ASR9K BGP BFD bundle-interface

~ dnzydn ~ Leave a comment

BFD session for BGP neighbor which is routed over bundle-interface can not be established without using below command ;

bfd multipath include location 0/0/CPU0

Before that for bfd session following error can be seen on show bfd session detail;

BFD_MP_DOWNLOAD_NO_LC.

BFD session must be tied to a specific location, Line card. With bundle configured and without that command BFD can not bind interface for the session as IOSXR uses LC for BFD sessions.

Below is nicely explanation for the behavior by Xander Thuijs ;

This I think is maybe nicely explained with this: Implementation of various BFD flavours over bundle interfaces in IOS XR was carried out in 3 phases:

  1. IPv4 BFD session over individual bundle sub-interfaces. This feature was called “BFD over VLAN over bundle”.
  2. IOS XR releases 4.0.1 and beyond: “BFD Over Bundle (BoB)” feature was introduced.
  3. IOS XR releases 4.3.0 and beyond: full support for IPv4 and IPv6 BFD sessions over bundle interfaces and sub-interfaces. For disambiguation from the BoB feature, this implementation is called BLB, and sessions are often referred to as native BFD sessions over bundle interfaces and/or sub-interfaces. BFD multipath must be enabled for any of these BFD flavours to work.

Due to the introduction of BLB (bfd over logical bundle) in XR43 this was necessary, I agree that you may have been mislead by the nomenclature of that multipath location keyword which suggests multihop, but it was meant to also include multipath as in multiple members of a bundle..

https://community.cisco.com/t5/xr-os-and-platforms/bfd-on-asr9k-cluster/td-p/2477664

Juniper EX 2200 Statik Route ve BFD Uygulaması

~ dnzydn ~ Leave a comment

Junos 10’dan sonra Statik routelarda BFD desteği var. Benim kullandığım junos 12.3. Ayrıca uygun lisansın’da yuklenmiş olması gerek (show log license).

Bu şekilde EX2200 üşteri demarc cihazı olarak konumlandırmak, ve aynı zamanda backup link için’de üzerinde routing yapmak mumkun oluyor. Aksi takdirde EX2200 ve PE arasında OSPF kurmak ve ana hattın gittiğini bu şekilde anlamak gerekiyor.

Bunun yerine EX2200 ve PE arasında BFD komuşuluğu kurup, statik route ile daha basit bir çözüm sağlanabilir.

 

1- BFD izleyen statik route eklemek :

next-hop olarak qualified-next-hop kullanılmıştır. Zira BFD route gittiğinde alternatif başla bir route’un kullanılması istenmiştir (backup link).

routing-options {
static {
route 0.0.0.0/0 { # Backup link
qualified-next-hop 5.5.5.1 {
preference 10;
}
qualified-next-hop 10.22.0.37 {
preference 5;
bfd-liveness-detection {
minimum-interval 500;
}
}
}
}
}

 

Cisco’da ise (PE olarak cisco kullanılıyor);

ip route static bfd GigabitEthernet0/0/2.90 10.22.0.35
ip route 192.168.47.0 255.255.255.0 GigabitEthernet0/0/2.90 10.22.0.35 ! müşteri ethernet bloğu

interface GigabitEthernet0/0/2.90
encapsulation dot1Q 90
ip address 10.22.0.37 255.255.255.248
bfd interval 500 min_rx 500 multiplier 3
!