Rsync between 2 datacenters not working

[Perry Hutchison]

Marc Roos via rsync <rsync at lists.samba.org> wrote:
> Hmmm, looks indeed like changing the mtu helps, strange thing is that 
> with the bigger mtu sometimes I had no problems and often TB are copied 
> without problems. 
> Problem is I can't test the connection that much because the connection 
> has been established by a third party and it is just some vlan without 
> any hops. 

VLANs are notorious for reducing the MTU by adding metadata to the
packets.

2 possible reasons why it sometimes works OK:

* Overall net performance is sometimes good enough that the
  fragmentation introduced by the VLAN has little impact.

* The 3rd party who sets it up may not always do it in
  exactly the same way.