Is my iptables broken? or my brain broken?

[Nanja]

I am so confused, how do I unlock my iptables? I don't know how to make sense! For some reason when I put an iptables rules it's supposed to show up in my iptables list right? I am not seeing any changes.

For example I type this

iptables -A POSTROUTING -t nat -s 10.10.10.0/24 -j MASQUERADE

I end up getting this

iptables -L
Chain INPUT (policy ACCEPT)
target     prot opt source               destination

Chain FORWARD (policy ACCEPT)
target     prot opt source               destination

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination

&&& A guide I am following says to add this

iptables -A POSTROUTING -t nat -s ‘10.10.10.0/24’ -o vmbr0 -j MASQUERADE

But I am getting this in return!!

iptables v1.8.7 (legacy): invalid mask `24’' specified
Try `iptables -h' or 'iptables --help' for more information.

The guide I am following on youtube is called "How to setup Proxmox with Single Public IP and share with VMs | Proxmox Tutorial"

I am supposed to enter this for my network to work? How do I do that when iptables won't even show the first entry.

iptables -A POSTROUTING -t nat -s 10.10.10.0/24 -j MASQUERADE
iptables -A POSTROUTING -t nat -s ‘10.10.10.0/24’ -o vmbr0 -j MASQUERADE
iptables -D POSTROUTING -t nat -s ‘10.10.10.0/24’ -o vmbr0 -j MASQUERADE

Please help, thanks.

 

[remark]

You need just second line:
iptables -A POSTROUTING -t nat -s 10.10.10.0/24 -o vmbr0 -j MASQUERADE

But before, list iptables rules in the nat table:
iptables -L -t nat

What is ip address and netmask of your vmbr0 interface?

 

[Nanja]

You need just second line:
iptables -A POSTROUTING -t nat -s 10.10.10.0/24 -o vmbr0 -j MASQUERADE

But before, list iptables rules in the nat table:
iptables -L -t nat

What is ip address and netmask of your vmbr0 interface?

iptables -L -t nat
Chain PREROUTING (policy ACCEPT)
target     prot opt source               destination         

Chain INPUT (policy ACCEPT)
target     prot opt source               destination         

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination         

Chain POSTROUTING (policy ACCEPT)
target     prot opt source               destination         
MASQUERADE  all  --  10.10.10.0/24        anywhere           
MASQUERADE  all  --  10.10.10.0/24        anywhere           
MASQUERADE  all  --  10.10.10.0/24        anywhere           
MASQUERADE  all  --  10.10.10.0/24        anywhere           
MASQUERADE  all  --  10.10.10.0/24        anywhere           
MASQUERADE  all  --  10.10.10.0/24        anywhere           
MASQUERADE  all  --  10.10.10.0/24        anywhere

 

[remark]

You have a lot of MASQUERADE rules you created with your experiments. Clear the nat table with "iptables -X -t nat" command.
Then, you do not have slave port for vmbr1. Is it right?

 

[Nanja]

You have a lot of MASQUERADE rules you created with your experiments. Clear nat table with "iptables -X -t nat" command.
Then, you do not have slave port for vmbr1. Is it right?

well.. I thought I would need a slave port, but the person in youtube video that I am following didn't seem to need one... & that he replied to someone saying they just needed to add a line in iptables. I cleared the iptables.

Also, how do I fix this problem? Is my version of iptables wrong or something?

iptables -A POSTROUTING -t nat -s ‘10.10.10.0/24’ -o vmbr0 -j MASQUERADE
iptables v1.8.7 (legacy): invalid mask `24’' specified
Try `iptables -h' or 'iptables --help' for more information.

 

[remark]

Try to type 10.10.10.0/24 without any quotes.
If you have spaces in ipaddress and mask, remove it!

 

[spirit]

remove ‘ character

 

[oryx17]

remove ‘ character

This worked for me.

 

[Pifouney]

pls note that iptables deprecated. Please prefer nftables, whose one is included with proxmox 8xx +