I'm realizing that our mirror (mirrors.coopvgg.com.ar) does not appear as updated in the mirror-status.centos.org within random time intervals. 

Here are some tests from the server:

rsync -4 --recursive --no-motd --times --links --hard-links --delay-updates --stats rsync://msync.centos.org/CentOS-incdvd /var/www/centos/

@ERROR: Unknown module 'CentOS-incdvd'
rsync error: error starting client-server protocol (code 5) at main.c(1524) [Receiver=3.0.7]

Our IP: 200.3.169.80 / 2001:13e8:2:3::80 (the ipv6 has changed, but the rsync command forces to use ipv4 that remains the same).

Maybe some servers does not have the proper ACL

Thanks.

---
Ariel S. Weher
Administrador Técnico
Dto. Sistemas & Networking
Cooperativa Telefónica de
Villa Gobernador Gálvez Ltda.
Tel: +54 341 4921299