On Wed, Mar 30, 2022 at 5:14 PM Adam Thompson <athompson@merlin.mb.ca> wrote:

Hi,

I’m successfully using BIRD with the Go Looking Glass from https://github.com/xddxdd/bird-lg-go.  I haven’t needed to use the birdc CLI until now, and I’m a bit confused by it in ways the docs don’t appear to address.

(I’m running default distro pkgs on Alma Linux 8.5, one of the post-CentOS RHEL rebuilds.)

 

The output I get looks like:

[root@lg2 ~]# birdc show route | head

BIRD 2.0.9 ready.

Table master4:

223.94.242.0/23      unreachable [uwpg_rtr1_v4 2022-03-26 from 216.73.71.131] * (100) [AS56041?]

                     unreachable [umrtr2_v4 2022-03-26 from 206.211.216.52] (100) [AS56041?]

                     unreachable [umrtr1_v4 2022-03-26 from 206.211.216.51] (100) [AS56041?]

181.123.200.0/22     unreachable [umrtr1_v4 2022-03-26 from 206.211.216.51] * (100) [AS23201i]

                     unreachable [umrtr2_v4 2022-03-26 from 206.211.216.52] (100) [AS23201i]

                     unreachable [uwpg_rtr1_v4 2022-03-26 from 216.73.71.131] (100) [AS23201i]

88.218.186.0/24      unreachable [umrtr1_v4 2022-03-26 from 206.211.216.51] * (100) [AS62240i]

                     unreachable [umrtr2_v4 2022-03-26 from 206.211.216.52] (100) [AS62240i]

 

  1. Is the “unreachable” bit normal on a looking glass / route collector?
It depends on your setup. It could affect best path selection if there are "reachable" routes, so be careful with that.
 
  1. What’s with the “?” at the end of some ASes?
This displays one of BGP attributes. It is not the bird's thing, it is usual BGP thing. Description from bird's documentation:

enum bgp_origin

Origin of the route: either ORIGIN_IGP if the route has originated in an interior routing protocol or ORIGIN_EGP if it's been imported from the EGP protocol (nowadays it seems to be obsolete) or ORIGIN_INCOMPLETE if the origin is unknown.

https://bird.network.cz/?get_doc&v=20&f=bird-6.html#rta-bgp-origin
 
  1. Where’s the AS paths?  All I seem to get is the terminal AS.
Use "all" switch for "show route" command to see all attributes.
https://bird.network.cz/?get_doc&v=20&f=bird-4.html#cli-show-route
 

 

I’m not sure if I’m not using the tool correctly, or if I’m even using the right tool in the first place.

 

Pointers / clues appreciated?

 

Thanks,

-Adam

 

Adam Thompson
Consultant, Infrastructure Services
MERLIN
100 - 135 Innovation Drive
Winnipeg, MB, R3T 6A8
(204) 977-6824 or 1-800-430-6404 (MB only)
athompson@merlin.mb.ca
www.merlin.mb.ca