Re: Simulation with Packet Lost and Packet Delays (How to set up a Linux Router between two subnets?)

Tony Yat-Tung Cheung
Wed, 24 Dec 2003 09:02:06 -0000

>From: Stef Coene <stef.coene@docum.org>
>To: tony.cheung@asiayeah.com,
>	Tony Yat-Tung Cheung <dragonman@asiayeah.com>, lartc@mailman.ds9a.nl
>Subject: Re: [LARTC] Simulation with Packet Lost and Packet Delays
>Date: Mon, 22 Dec 2003 17:03:27 +0100
>
>On Sunday 21 December 2003 16:31, Tony Yat-Tung Cheung wrote:
>
>
>>Hi All,
>>
>>I would like to be able to simulate network congestion and delay on
>>tcp/udp connections between two hosts. I would need to simulate packet
>>lost and packet delay.
>>
>>I think I would need to use a Linux box with two network cards to act as
>>a pass-through ethernet bridge. Is it the case? Does this how-to guide
>>provides good information in this area?
>>
>>
>http://snad.ncsl.nist.gov/itg/nistnet/
>
>Stef
>
>
Hi Stef and others,

Thanks. The NISTNET looks like a very decent package. I have tried it
briefly on a Red Hat 7.2 and it seems to work fine.

I have another basic question and I would if anyone could help me out.

Basically, I am trying a setup a Linux router between two local subnets,
192.168.0.1/24 and 192.168.1.1/24. My Linux box has two ethernet cards,
eth0 has IP address 192.168.0.1 (subnet mask 255.255.255.0) and eth1 has
IP address 192.168.1.1 (subnet mask: 255.255.255.0). Now I wish my Linux
box to be able to route traffic between eth0 and eth1.

I have modified ''/etc/sysctl.conf'' to,

# Controls IP packet forwarding
net.ipv4.ip_forward = 1

However, it doesn''t seem to work right now. Is there anything else I
need to do? I wish to set it up quickly and would appreciate any advice!

Thank you.

Best Regards,
Tony Cheung