[NTLUG:Discuss] Network problems

[Chris Cox]

In 2.0 Linux I know I had to enter a route for the broadcast address (weird).
I had to creat a dummy host entry in /etc/hosts to pull this off.

dummy 255.255.255.255

Then add dummy as a host route.

Hope this helps,
Chris

Keith Rice wrote:
> 
> James Corona wrote:
> >
> > I'm having trouble getting a RedHat 5.1 server to talk on my network.  I
> > have a 5.2 server running without a problem and have tried to compare
> > configurations; there is nothing obviously different.  I can ping both
> > directions server - client  client - server but when I try to get an IP
> > number through DHCP.  Using the debugger I can see the server receives the
> > request but when it responds it gives an error that says Network
> > Unavailable.  In addition I am using diald to automatically connect to my
> > ISP.  When a request is sent from the client the connection is activated but
> > no data is ever recieved.  This is making me crazy,  where else might I
> > look?
> >
> > Thank
> >
> > James
> 
> I experienced a problem with dhcpd with RH 5.1 which sounds like yours. I had to
> make sure that the default route on the server (the RH 5.1 box) was set to my
> ethernet card (route add default eth0) and then it worked fine except when I
> went online because my default route was set to my ppp connection. I had to
> tweak my ppp-off script to switch the default route back to eth0 after I
> disconnected. When the ppp-on script called pppd it specified that the default
> route was to be set to the ppp link. When I reloaded my system with Mandrake 5.2
> the problem went away. I assume the problem is with the version of dhcpd and not
> RedHat 5.1 but I never tried to upgrade my dhcpd to find out. I suggest that you
> upgrade to the latest dhcpd and see if that helps. Otherwise, if you don't want
> to try the upgrade you can try tweaking the ppp scripts to do the default route
> switching.
> 
> About your problem of not receiving data once diald activates your connection.
> It looks like it may be one of a couple of things. It could be that you don't
> have a routing table entry for your local net. Try adding a static route for
> your local net. My LAN uses private Class C addressing. My subnet is
> 192.168.0.0. Here's my /etc/sysconfig/network-scripts/ifcfg-eth0 file:
> 
> DEVICE=eth0
> IPADDR=192.168.0.1
> NETMASK=255.255.255.0
> NETWORK=192.168.0.0
> BROADCAST=192.168.0.255
> ONBOOT=yes
> 
> This way, even if you are online, all packets from your server sent to systems
> on your LAN are sent out the correct interface.
> 
> If this doesn't work, you may not have IP forwarding enabled on your server. You
> can enable it by changing your FORWARD_IPV4 setting in /etc/sysconfig/network to
> true. Also, be sure to setup IP masquerading using ipfwadm. See the Linux IP
> Masqurade mini HOWTO for help on this step.
> 
> I hope this helps you out.
> 
> Keith
> 
> --
> Keith Rice           E-Mail..: dkrcomp at earthlink.net
> Hurst, Texas, USA    WWW.....: http://home.earthlink.net/~dkrcomp
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