Subject: Re: Setting up policy routing
To: Sumit Pandya <sumit@elitecore.com>
From: pjv <valdez@froggy.com.au>
List: tech-net
Date: 04/27/2002 11:23:12
What is iptables? is this the new ipf? :P 
On Fri, 26 Apr 2002 19:10, you wrote:
> Hi All,
> 	Below is my setup
> Corporate Computer 1
> +-----------------+		Linux router/Host
>
> |192.168.1.2	 |-------+	+----------------+ 10.1.1.1 with gateway 10.1.1.2
>
> +-----------------+	| 	|		|---------------------
> 		        HUB -----|192.168.1.1	|
> +-----------------+	| 	|		|---------------------
>
> |192.168.1.130	  |------+	+----------------+172.16.0.1 with gateway
>
> 172.16.0.2
> +-----------------+
> Corporate Computer 2
>
> 	My corporate network is setup with 192.168.1.0/24. Lower-end of this
> network; i.e. from IP 192.168.1.2 to 192.168.1.125; is for higher
> authorities of organization and remaining 192.168.1.128 to 192.168.1.254
> IPs are assigned to rest of the employee's computer. My Internet access
> server has 2 connections to Internet; say 10.1.1.1 with gateway 10.1.1.2,
> speed 128Kbps and 172.16.0.1 with gateway 172.16.0.2 speed 64Kbps.
> 	I want computers of higher authority will go from 128Kbps link. For that I
> add following routing entries with "ip" command of iproute2.
> 	# ip rule add from 192.168.1.0/25 table 128speed
> 	# ip route add via 10.1.1.2 table 128speed
> 	# ip rule add from 192.168.1.129/25 table 64speed
> 	# ip route add via 172.16.0.2 table 64speed
>
> 	# iptables t nat A POSTROUTING -j MASQUERADE
>
> 	After this setup I cannot access either Linux router or Internet because
> all reply goes to device of default route for my computers. I.e.
> packets/responses for computer 192.168.1.130 go to interface with IP
> 172.16.0.1. This is because routes for my internal network is there in
> table "main" and my rules are added before the rule to traverse "main". Now
> what I want is entries of main table (or rule to traverse main table) is
> consulted before my rules.
> 	While defining "rules" I can specify preference with "pref" option to "ip
> rule add ...", so my rules will be traveled after main table. But here in
> this case problem is entry of default route in table "main". Finally I
> removed that default route from table main and everything worked for me.
> 	Now my questions are
> 1> Before all above described solution, I try to get it working by
> specifying metric 2 in the route I added into my rules but that doesn't
> worked. Is scope of metric is limited of one rule?
>
> 2> Does there exist any easier solution then what I did in my setup?
>
> 3> Do you think to get this configuration activated at system bootup I add
> a nice script in rc.local or any other way?
>
> Thanks for replies.
> --Sumit