two ISP's woes?
Brent Clark
bclark at eccotours.dyndns.org
Thu Aug 25 17:09:12 CEST 2005
Hi list
K im into my third week now and I still have not resolved this routing / second isp issue.
I have been fortunate in that someone advised me that I this is not as complex has I initially had thought and I just use the ROUTE target.
I initially tried from the following example:
http://lartc.org/howto/lartc.rpdb.multiple-links.html
which too did not work for me.
any way my setup is so:
| INTERNET | (I sure hope this gets displayed correctly)
----------------------------------------
| |
|(Static IP) |(Dynamically assigned ISP)
-------- ---------
| ISP A | | ISP B |
-------- ---------
| 196.36.10.113 | 192.168.10.200
| |
| |
| | 192.168.10.100 (eth2)
| 196.36.10.114 (eth0) ------
-------------------| My FW |
--------
| 192.168.111.10 (eth1)
|
|
-------------------------- internal network
192.168.111.0/24
ISP A = Internet Solutions ADSL ROUTER
ISP B = Telkom ADSL MODEM
My ROUTE modules:
gate:/var/log# lsmod
Module Size Used by
ipt_ROUTE 5272 0
gate:/var/log#
My default routing is as so:
gate:~# ip route show table main
196.36.10.112/29 dev eth0 proto kernel scope link src 196.36.10.114
192.168.111.0/24 dev eth1 proto kernel scope link src 192.168.111.10
192.168.10.0/24 dev eth2 proto kernel scope link src 192.168.10.100
default via 196.36.10.113 dev eth0
gate:~#
And test firewall ruleset:
$IPT -A POSTROUTING -t mangle -p tcp --dport 80 -j ROUTE --oif eth2
# SNAT the Private LAN
$IPT -t nat -A POSTROUTING -o eth0 -s 192.168.111.0/24 -j SNAT --to-source 196.36.10.114
$IPT -t nat -A POSTROUTING -o eth2 -s 192.168.111.0/24 -j SNAT --to-source 192.168.10.100
$IPT -t filter -A FORWARD -m state --state ESTABLISHED,RELATED -j ACCEPT
$IPT -t filter -A FORWARD -m state --state INVALID -j LOG --log-prefix "INVALID forward: " --log-tcp-options --log-ip-options
$IPT -t filter -A FORWARD -m state --state INVALID -j DROP
$IPT -t filter -A FORWARD -i eth1 -o eth0 -m multiport -p tcp --dport 25,53,110,113,123,143,6667 -m state --state NEW -j ACCEPT
$IPT -t filter -A FORWARD -i eth1 -o eth0 -m multiport -p udp --dport 53,123,500 -m state --state NEW -j ACCEPT
$IPT -t mangle -A FORWARD -i eth1 -p tcp --dport 80 -j ROUTE --oif eth2 --continue
#$IPT -t mangle -A FORWARD -i eth1 -p tcp --dport 80 -j ROUTE --oif eth2
#$IPT -t filter -A FORWARD -i eth1 -o eth2 -m multiport -p tcp --dport 80,443 -m state --state NEW -j ACCEPT
What im trying to achieve is that all my traffic goes out eth0 (196.36.10.114 / ISP A) except for all HTTP traffic, that I would like to go out ISP B.
I may be having a problem where by my ADSL ISP B modem has to NAT twice ( (But I dont see this as an issue) FROM 192.168.111.0 / 24 to 192.168.10.0/24 to dynamicly assigned IP).
I suppose I can get the modem to work in bridging mode, but I first want to get this experimentt working first before I venture down this path.
I got this gut feeling that this is doable and can work, but I just dont know where Im falling short.
as I aways ask, if anyone has got any tips or tricks that could help me, I would be most greatful.
Kind Regards and thanks in advance.
Brent Clark
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