Re: I can send packets but I receive nothing, routing problem
From: riviereg (guillaume_at_nomail.org)
Date: Sat, 04 Sep 2004 18:04:24 +0700
Alex Harsch wrote:
> riviereg wrote:
>>Dear all linux networking,
>>I try to set up a route to my ISP:
>>my 10.0.0.0 network is connected to the router on eth0
>>my ISP is on link eth2 on my router (GNU/Debian sarge, kernel 2.6.8, I
>>try with 2.6.7 same problem).
>>my external IP is 220.127.116.11
>>my gateway is 18.104.22.168 (this is my modem, with a real IP address)
>>I try to route my internal IP 10.0.0.1 to this ISP
>>my route is configure like this:
>># ADSL line
>>ip route flush table 5
>>ip route add table 5 default via 22.214.171.124 src 126.96.36.199 dev eth2
>>ip rule add fwmark 5 table 5
>>my Nat is like this
>>iptables -t mangle -A PREROUTING -s 10.0.0.1 -j MARK --set-mark 5
>>iptables -t nat -A POSTROUTING -o eth2 -s 10.0.0.1 -j SNAT --to 188.8.131.52
>>All is ok, I can access to my modem (184.108.40.206) from 10.0.0.1, I can also
>>access to internet on this modem (there is a web site on the modem).
>>But when I try to access to Internet from 10.0.0.1, I can "find" sites
>>but I receive nothing, all my ping are lost. This problem drive me crasy
>>I think I send packets but there is a kind of incoming reply routing
>>problem. All other IP's from my internal network can connect with the
>>default gateway on my first ISP (eth1).
>>Thank you for Help me on this,
> Bon Jour Guillaume,
> I think, you have a couple of problems here. First of all, you default
> gateway should not be the modem, but your interface pppx.
> Additionally, I think you have not configured your firewall to allow
> incoming related/acknowledged packets.
Thank you for this Alex,
I fact I have a modem gateway with an assigned real IP Address,
Internal Network ----| Linux box |-----| Modem gateway |----
| Computer x |
I aslo try to connect directly a computer (x) to the Modem gateway,
with this modem as gateway and another real IP address provided by
my ISP. From computer X I can access to Internet, no problem
How to configure my firewall to allow incoming related/ackowledged
packets ? I think my problem is something like this.
Thank you very much for help,