Block Portmapper 111

[TechLineX]

Hi,

I want to block portmapper 111 for all VMs in our 4 Node-Cluster.

I set the firewall at the datacenter-level -> No effect
host-level -> no effect

vmbr0 public ip (either of the vms)
vmrb1 internal ip (management - network)

Firewall is set to accept all, I want to block specific ports for the vms. Its not a possability to set the rule for each vm, I want to set it as default for all vms.

I will attach the active rules.

Thank you in advance

 

[Richard]

I want to block portmapper 111 for all VMs in our 4 Node-Cluster.

I set the firewall at the datacenter-level -> No effect
host-level -> no effect

vmbr0 public ip (either of the vms)
vmrb1 internal ip (management - network)

Firewall is set to accept all, I want to block specific ports for the vms. Its not a possability to set the rule for each vm, I want to set it as default for all vms.

Setting via GUI is only possible by setting the rule per VM and interface.


But you can do it by command

 iptables -I FORWARD -p udp --dport 111 -j DROP

in each Proxmox node.


Note: you can have Proxmox's firewall active at the same which will work independently (in case of a contradiction your explicit setting for port 111 has priority). If you don't use Promox's firewall set

echo 1 > /proc/sys/net/bridge/bridge-nf-call-iptables

 

[TechLineX]

Thank you for your reply.

I can't disable rpcbind for all nodes, because I'm using nfs-shares at eth1. It it neccessary to block port 111 only for eth0.

Best regards

 

[Richard]

I can't disable rpcbind for all nodes, because I'm using nfs-shares at eth1. It it neccessary to block port 111 only for eth0.

You can add more filter criterias as you like, e.g. (assuming interface eth0 is a port at vmbr0):

iptables -A FORWARD -i vmbr0 -p udp --dport 111 -j DROP

 

[TechLineX]

Is portmapper only tcp? I read it´s also tcp.

Best regards

 

[Richard]

Is portmapper only tcp? I read it´s also tcp.

AFAIK both, run

iptables -A FORWARD -i vmbr0 -p udp --dport 111 -j DROP
iptables -A FORWARD -i vmbr0 -p tcp --dport 111 -j DROP

For details how to use iptables study it's man page!

 

[TechLineX]

Done. I will report, if it helped. Thank you!

 

[TechLineX]

It worked. Thank you! You can close this thread.

 

[Stoiko Ivanov]

As thread-creator you can (and are highly encouraged to) mark the thread as solved yourself - just edit it and set the tag solved.
Thanks!