[SOLVED] local lan works only when dsl is connected

[riamoh]

hello all,

i am pretty new to linux and to ubuntu. i have a wired lan setup (four machines) as well as a dsl connection that is shared among all machines via a standalone Baylan switch. A Zyxel DSL modem is connected to the switch. As far as IP, Netmasks go, there are no static ips configured as the DSL provider configures the IPs automatically. The only configuration is the DSL providers primary and secondary DNS.

the phone lines, however, are pretty bad so the dsl connection keeps dropping quite frequently. The problem is that when the dsl connection is dropped, access on the local lan also goes with it.

I did not reconfigure any network settings upon installation since ubuntu 8.04 worked right out of the box - the internet and the lan (after doing the sharing bit) was connected. It was only when the DSL went down that I realized that my LAN was not working. Also, when I try to configure my eth0 i get an error message saying that the interface does not exist.

Could anyone help!

[nareshjethva]

first of all you have to know you are using dhcp protocol
that's the problem
your ip provided by dhcp & dhcp works on DSL
when DSL goes down your ip....... also !!!!!

[riamoh]

So what should I do? Could someone please explain what can be done to fix this?

[nareshjethva]

give manual ip to all of your PC & remove DHCP

[coopstah13]

you need a router, i assume your ISP is only going to provide you with one IP address, you need to share taht IP address across all of your machines using NAT, that way even if the internet is down, the internal network is not, when the net connection is plugged directly into a switch, it assumes the net connection is going to do the routing, which is why you are having a problem

[riamoh]

you need a router, i assume your ISP is only going to provide you with one IP address, you need to share taht IP address across all of your machines using NAT, that way even if the internet is down, the internal network is not, when the net connection is plugged directly into a switch, it assumes the net connection is going to do the routing, which is why you are having a problem

that makes perfectly logical sense! thank you!

regards,

omair