Re: forwarding internet connection

["Jörg Harmuth" <harmuth@mnemon.de>]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
 
Hi,

as far as I unstand your posting, you want to forward traffic based on
the source IP of the client. So, some clients should use ISP1 and some
ISP2. You could write per client:

## Rewriting destination address
iptables -t nat -A PREROUTING -s $IP_OF_CLIENT -j DNAT --to $IP_ISP2

## Allow forwarding of connections
iptables -A FORWARD -s $IP_OF_CLIENT -d $IP_ISP2 -m state \
- --state NEW,ESTABLISHED,RELATED -j ACCEPT
iptables -A FORWARD -d $IP_OF_CLIENT -s $IP_ISP2 -m state \
- --state ESTABLISHED,RELATED -j ACCEPT

## Maybe you need SNATing. If so:
iptables -t nat -A POSTROUTING -s $IP_OF_CLIENT -d $IP_ISP2 -j SNAT
- --to-source $IP_ISP1

May be, you can additionally add interface or protocol specifications
or the like. I don't know, because your exact network layout is unknown.

A very good tutorial on iptables is here:

http://iptables-tutorial.frozentux.net/chunkyhtml/index.html

Have a nice time,

Jörg

elg3ne schrieb:

| Hi guys...Im new to iptables please help me with my problem...
|
| How do I forward incoming traffic to a diffent machine? example is
| that I have 2 ISP 1 is primary & the other 1 is backup only... Now
| I want to utilize the backup ISP because it is not being used...
|
| I dont want to make changes per PC to PC just to change their
| gateway or proxy to use the backup ISP...
|
| How do I forward the incoming request to my primary ISP to 2nd ISP?
|
|
| For example client has 192.168.1.11 IP and I want the IP to use the
| 2nd ISP instead the 1st ISP..
|
| Btw Im using squid to access the internet for my client.
|
| Sorry if my explanation is not good...but I hope someone could help
| me...
|


- --
- -----------------------------------------------------------------------
mnemon
Jörg Harmuth
Marie-Curie.Str. 1
53359 Rheinbach

Tel.: (+49) 22 26  87 18 12
Fax:  (+49) 22 26 87 18 19
mail: harmuth@mnemon.de
Web:  http://www.mnemon.de
PGP-Key: http://www.mnemon.de/keys/harmuth_mnemon.asc
PGP-Fingerprint: 692E 4476 0838 60F8 99E2  7F5D B7D7 E48E 267B 204F
- -----------------------------------------------------------------------
Diese Mail wurde vor dem Versenden auf Viren und andere schädliche
Software untersucht. Es wurde keine maliziöse Software gefunden.

This Mail was checked for virusses and other malicious software before
sending. No malicious software was detected.
- -----------------------------------------------------------------------

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.5 (MingW32)
Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org
 
iD8DBQFCJbLyt9fkjiZ7IE8RAlYQAKCXvDV8MfHDaIH6GJa1jay56A+t2ACdFZ7w
MlbrDGj7qFY14xeWA+ULBB4=
=+e3D
-----END PGP SIGNATURE-----