how i fixed it: making dialup and LAN work together

[Guest southernguy]

i had this problem and many other people apparently have too.

 

the problem: on a LAN, Mandrake likes to set you up by default to access the internet thru the LAN, using whatever machine on the LAN has a direct connection as the gateway. when you dial up, that gateway doesnt always get changed just because your modem is connected, which results in you still accessing the net over the LAN while your modem twiddles its thumbs.

 

the first ugly hack i found: disable the LAN interface before dialing, and re-enable it when you disconnect. that gets you on the net via modem but you lose LAN connectivity.

 

the fix, part one: edit or create a file /etc/ppp/ip-up.local, and in it put:

 

route del default

route add default gw $IPREMOTE

 

the first line deletes the LAN gateway, the second adds the gateway your ISP gave when pppd started. so far so good, you are modeming to the internet now and your LAN is still available.

 

problem part two: when you disconnect, this gateway is still set, so you then cannot go back to the internet over the LAN, even tho you can access the LAN for file sharing etc.

 

the fix, part two: you need to delete the modem-internet gateway and put the LAN one back. there may be a better place or file to put this but what i did was make a file /etc/ppp/routefix and let kppd execute it after disconnect, with these lines:

 

route del default

route add default gw 192.168.0.1

 

of course change that to suit how your LAN is numbered and which machine on it has internet access.

 

great thanks and gratitude to the other posts on here about this which led me to getting it working, and to the man pages.

 

if anyone knows a better way to reset the LAN as gateway please post, this is just what i could do with my little thimble of knowledge.

 

--- EDIT ---

 

i have discovered since writing this that if i call the file 'ip-down.local' instead of my made-up name, it will automatically get executed when you disconnect the modem, and you dont have to tell kpppd to run it, like i did with my made-up file.

 

--- /EDIT ---

[Guest shakti]

if what you want to do is use internet via modem and local lan via eth at the same time just edit /etc/config/network as root and delete the line that says GATEWAY......

[apbsa]

Hi Shakti, I was going to try your method of getting the LAN to work with my dialup connection, but I don't have the file /etc/config/network on my system. Is there another simple method to get dialup working with my LAN that doesn't involve compromising my security?

 

I did manage to get both working at the same time, but I have probably just reduced my security level to zero. I edited the /etc/shorewall/policy file and changed all the settings to ACCEPT.

 

I tried the firestarter firewall, and it enabled me to use PPP dialup and my LAN at the same time. It was easy to use, but it doesn't work with KPPP unless you manually start it after you are connected.

 

Has anyone else got some simple methods of getting this working? I have tried reading the shorewall documentation, but find it difficult. Thanks in advance.

[Steve Scrimpshire]

Forgive me if I'm wrong here, because I'm basically a newbie with networking (my Linux box is the server in my 2-computer LAN), but can't you set up the eth0 gateway with wizdrake and it not interfere with the default gateway associated with ppp0?

 

I also use bastille-netfilter for my firewall and used InteractiveBastille to configure it (I then had to tweak a couple things in /etc/Bastille/bastille-firewall.cfg). It asks simple questions about your setup and configures based on the answers.

 

I'm still using 8.1, BTW.