Rare project developers

[mc36 <>]

hi,
so bgp peer establishment is somewhat random: the original rfc does not 
mention that the higher/lower ip should initiate the tcp
so i'm copying the ios xr behavior: it tries active then passive open with 
random timers and fingers crossed, it'll come up...
all my interop with cisco xr, cisco xe, junos, frr and self tests (about 800 
bgp tests in total) pass fine without a single
retry so it cannot be that bad.. the only issue i know about is with bird in 
my dn42 peerings, which does wildcard listen on
port 179, causing every active open to succeed, but sometimes it's 
simultaneous with their active open resulting in collisions
at the bird side.. then their side closes one or the other without a notify 
message causing log flood on freerouter side
until the session finally comes up...
in your topology, i've a lot of questions:
-what is that (as10, as20, as30) notation? the common way is that one box 
belongs to one asn?
-what box is freerouter and what the other boxes are?
-do you see anything in the freerouter and the opposite box's logs?
-can you share the simulation in order to be able to reproduce?
-if not, can we have a debug session together?
thanks,
cs


On 1/4/23 12:24, Maria Del Carmen Misa Moreira wrote:
> Hi,
>
> I have a full mesh topology RX configured with iBGP, OSPF, 3 VLANs and 3 VRFs (BGP is configured with the address of the loopbacks: 1 loopback per VLAN). Every router has a client 
> RXX with OSPF passive, eBGP, a different AS number and 1 VRF.
>
> (AS100)   R11 ---- (AS10, AS20, AS30) R1 ---- (AS10, AS20, AS30)R4 ---- 
> (AS400) R44
> *|*|**
> (AS200) R22 ---- (AS10, AS20, AS30) R2 ---- (AS10, AS20, AS30) R3 ----(AS300) 
> R33
>
> The topology is working fine so I can ping each other, iBGP is up but eBGP is not completly up. I noted that R11 and R22 are always up but for R33 and R44 it depends... This is the 
> behaviour that I'm seeing: I run the simulation and R11/R22 bring up and also R33 (not R44), then, I run again the simulation with exactly the same configuration and sometimes it 
> happens that R44 brings up and not R33 or even worst none of them (R33, R44).
>
> Any idea? I have no idea why only one of those (R33, R44) brings up and not 
> the other and when you run it again it be opposite behaviour.
>
> Cheers,
> Camen Misa