servers redirection

servers redirection

[Chiara Simoni]

Hi,
I need to redirect all requests to my server "Xserver:Xport", to server 
"Yserver:Yport".

For some months I've been using these iptables commands,
with Destination NAT and Source NAT on server "Xserver":

/sbin/iptables -t nat -A PREROUTING  -p tcp -d "$Xserver" --dport 
"$Xport"  -j DNAT --to-destination "$Yserver:$Yport"
/sbin/iptables -t nat -A POSTROUTING -p tcp -d "$Yserver" --dport 
"$Yport" -j SNAT --to-source "$Xserver"

Now, these same commands don't work any more,
and I don't now why.
Recently the only changes I made on my servers
is a reboot.

Can you help me?
Have I made some mistakes on these commands?

Thanks

Ch.

Re: servers redirection

[U.Mutlu]

The following link has a solution for a similar scenario
"By using iptables and its masquerade feature, it is possible
to forward all traffic to the old server to the new IP":
   http://www.debuntu.org/how-to-redirecting-network-traffic-a-new-ip-using-iptables


Chiara Simoni wrote, On 10/18/2012 02:39 PM:
> Hi,
> I need to redirect all requests to my server "Xserver:Xport", to server "Yserver:Yport".
>
> For some months I've been using these iptables commands,
> with Destination NAT and Source NAT on server "Xserver":
>
> /sbin/iptables -t nat -A PREROUTING  -p tcp -d "$Xserver" --dport "$Xport"  -j DNAT --to-destination
> "$Yserver:$Yport"
> /sbin/iptables -t nat -A POSTROUTING -p tcp -d "$Yserver" --dport "$Yport" -j SNAT --to-source "$Xserver"
>
> Now, these same commands don't work any more,
> and I don't now why.
> Recently the only changes I made on my servers
> is a reboot.
>
> Can you help me?
> Have I made some mistakes on these commands?
>
> Thanks
>
> Ch.

Re: servers redirection

[Jan Engelhardt]

On Thursday 2012-10-18 23:13, U.Mutlu wrote:

> The following link has a solution for a similar scenario
> "By using iptables and its masquerade feature, it is possible
> to forward all traffic to the old server to the new IP":
>  http://www.debuntu.org/how-to-redirecting-network-traffic-a-new-ip-using-iptables

Well, masquerade (and other NAT targets) do forward traffic per se - 
routing would do that instead -, it merely changes the address.