[CentOS] Centos6.4 routing problem

[Ljubomir Ljubojevic]

On 06/04/2013 04:20 PM, Steve Clark wrote:
> On 06/04/2013 09:20 AM, Johan Vermeulen wrote:
>> in iptables, prerouting and masquerading are configured :
>>
>> # Firewall configuration written by system-config-firewall
>> # Manual customization of this file is not recommended.
>> *nat
>> :PREROUTING ACCEPT [0:0]
>> :OUTPUT ACCEPT [0:0]
>> :POSTROUTING ACCEPT [0:0]
>> -A POSTROUTING -o eth+ -j MASQUERADE
>> -A POSTROUTING -o em2 -j MASQUERADE

> Shouldn't this be em1?

Yes, -o is outgoing and it should be em1, not em2

>> COMMIT
>> *filter
>> :INPUT ACCEPT [0:0]
>> :FORWARD ACCEPT [0:0]
>> :OUTPUT ACCEPT [0:0]
>> -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
>> -A INPUT -p icmp -j ACCEPT
>> -A INPUT -i lo -j ACCEPT
>> -A INPUT -i eth+ -j ACCEPT
>> -A INPUT -i em2 -j ACCEPT
>> -A INPUT -m state --state NEW -m tcp -p tcp --dport 22 -j ACCEPT
>> -A FORWARD -m state --state ESTABLISHED,RELATED -j ACCEPT
>> -A FORWARD -p icmp -j ACCEPT
>> -A FORWARD -i lo -j ACCEPT
>> -A FORWARD -i eth+ -j ACCEPT
>> -A FORWARD -i em2 -j ACCEPT
>> -A FORWARD -o eth+ -j ACCEPT
>> -A FORWARD -o em2 -j ACCEPT

Check if you should have this line. It has been a long time I needed to 
use iptables for forwarding, nut I do not remember using -A FORWARD and 
-o together.
Do you at all need all those -A FORWARD lines for masquerading?

>> -A INPUT -j REJECT --reject-with icmp-host-prohibited
>> -A FORWARD -j REJECT --reject-with icmp-host-prohibited
>> COMMIT
>>


-- 
Ljubomir Ljubojevic
(Love is in the Air)
PL Computers
Serbia, Europe

StarOS, Mikrotik and CentOS/RHEL/Linux consultant