[Techtalk] no gateway, yet it works!

[Conor Daly]

On Wed, Sep 11, 2002 at 09:25:18PM -0700 or so it is rumoured hereabouts, 
Carla Schroder thought:
> OK, here's a fun lil mystery. Nowhere can I find a gateway setting on my home 
> network- I have a little Linksys NAT firewall box. The gateway is 
> 192.168.1.1, how original, but none of the client PCs have a gateway assigned 
> to them. I've looked in every config file I can find:
> -redhat-config-network, the GUI configurator
> -/etc/sysconfig/network- empty
> 
> ifconfig shows no gateway. so why does it work? I have Internet and DHCP and 
> everything, how in de hell do the client PCs find the Linksys box???
> 
> I thought I knew this stuff......

[cdaly at Valkerie cdaly]$ grep -i gateway /etc/sysconfig/*
/etc/sysconfig/network:GATEWAY="192.168.1.254"

This machine has a fixed network setup.  Another set of machines (which I
can't get at just now) use dhcp.  They have no ip info whatsoever in
/etc/sysconfig/network, I think they just have the line "PROTO=DHCP" or
something like that.  The routing information is supplied by the dhcp
server.  In this case, 

[cdaly at genesis kickstart]$ more /etc/dhcpd.conf
shared-network server.local.domain {
        option routers 192.168.50.1;
        option domain-name-servers 192.168.50.1;
        option domain-name "server.local.domain";

        subnet 192.168.50.0 netmask 255.255.255.0 {
                range 192.168.50.11 192.168.50.25;
                default-lease-time 600;
                max-lease-time 2592000;
                option subnet-mask 255.255.255.0;
                option broadcast-address 192.168.50.255;
        }
}

"option routers xxx.xxx.xxx.xxx"

supplies the gateway info for the default route...

Conor
-- 
Conor Daly <conor.daly at oceanfree.net>

Domestic Sysadmin :-)
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