<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META http-equiv=Content-Type content="text/html; charset=us-ascii">
<META content="MSHTML 6.00.2900.3492" name=GENERATOR></HEAD>
<BODY>
<DIV><FONT face=Arial size=2><SPAN class=914242317-25082009>I have the need to
interface a Linux system to two separate subnets. I have run into a
problem when one of the ports goes down due to either being disconnected for a
minute or due to no network traffic for approximately 3 minutes. When the
port goes down it routes the down-port's output to localhost.
When a valid message is then received from a gateway, the system looks into the
routing table and gets confused because it finds two default gateways (one for
each subnet). The confusion occurs even though the default gateways are
assigned to individual interfaces (eth0 - eth1). If it picks the wrong
default gateway, it cannot reach the gateway, so it assumes that the
network is still down and sends the response to itself. There must be a
timer involved here too because after 4 to 5 minutes the interface
re-establishes itself and works fine. As long as there is regular traffic
through the gateway the interface never goes down.</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=914242317-25082009></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2><SPAN class=914242317-25082009>I have heard that
there can be multiple routing tables, one for each port and that a priority
routing database is used to assign tables to ports. Has anyone had to
implement multiple routing tables? Does the database need to know the
subnet address for every message received through its
gateway? </SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=914242317-25082009></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2><SPAN class=914242317-25082009>I really want to
keep the configuration of this system as simple as possible, as people who know
less about networking than I do (if that is possible) will have to set up the
port parameters. Ports will have fixed address, no
DHCP.</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><SPAN class=914242317-25082009><FONT face=Arial size=2>L. A.
Weber</FONT></SPAN></DIV></BODY></HTML>