[DRBD-user] Conflict between drbd and iptables

[Diego Julian Remolina]

> My problem seems to be a conflict between drbd and the iptables firewall :
> 
> My iptables configuration on the two nodes includes the line :
> -A RH-Firewall-1-INPUT -s NODE_IP_ADDRESS -p tcp --dport 7789 -j ACCEPT

This is pretty much what I use and I have no problems on my machines (4 separate systems). However 
they do have SELinux disabled. Double check that you are using the IP address from the other node in 
the iptables file. And if you are connecting the two servers directly via a cross-over cable, then 
you should simply allow all traffic in that interface with:

-A RH-Firewall-1-INPUT -i ethX -j ACCEPT

where ethX is the interface you use for drbd.

Here is a link to my DRBD Howto firewall section just in case:

https://services.ibb.gatech.edu/wiki/index.php/Howto:Software:DRBD#Firewall_Configurations

I am currently running the latest 0.7.20 release but it also worked with the 0.7.17 in the past with 
no problems.

Diego