[CentOS] iptables: forwarding on internal device

Mon Feb 9 08:44:24 UTC 2009
John <jses27 at gmail.com>


> -----Original Message-----
> From: centos-bounces at centos.org 
> [mailto:centos-bounces at centos.org] On Behalf Of Marcus Moeller
> Sent: Monday, February 09, 2009 2:59 AM
> To: CentOS mailing list
> Subject: Re: [CentOS] iptables: forwarding on internal device
> 
> Good Morning,
> 
> iptables -L -v now shows:
> 
>     0     0 ACCEPT     all  --  eth0   eth0    anywhere
> anywhere            state NEW,RELATED,ESTABLISHED
> 
> But the packages are still dropped:
> 
> Feb  9 10:48:20 firewall kernel: DROP-TCP IN=eth0 OUT=eth0
> SRC=192.168.100.192 DST=172.28.2.161 LEN=44 TOS=0x00 PREC=0x00 TTL=59
> ID=54 PROTO=TCP SPT=9100 DPT=4068 WINDOW=0 RES=0x00 ACK SYN URGP=0
> 
> Could it be that I have to enable something in proc to allow
> forwarding on an internal device?
> 
> Best Regards
> Marcus

Yes that would be correct Marcus echo it into /proc or in /etc/sysctl.conf
would be
# Controls IP packet forwarding
net.ipv4.ip_forward = 1

JohnStanley