On 18.08.2017 19:05, Erik Christiansen via luv-main wrote:
It is a long time since I mucked with static routing. You can use the route command to specify routes for subnets, subnet masks, and the IP of the gateway. You could use the two subnets you have; 192.168.0.0/24 and 92.168.1.0/24, one on each side of the firewall. In each case, the subnet mask would be 255.255.255.0.
Looking at what I have on this host, talking directly to my modem, I see:
$ netstat -rn Kernel IP routing table Destination Gateway Genmask Flags MSS Window irtt Iface 0.0.0.0 192.168.1.1 0.0.0.0 UG 0 0 0 eth0 192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
0.0.0.0 denotes the default route, so here anything not for the local 192.168.1.0/24 subnet goes to the gateway (192.168.1.1), which is the modem. Really simple.
There are a number of examples in the "route" manpage. I did some reading in the O'Reilly "TCP/IP Network Administration" book before cutting loose, but my copy is a quarter of a century old now. A quick google of "linux static routing howto" showed a bunch of promising hits. There's likely to be more current information in them. E.g. the "ip" command seems to be popular this century, so let's try:
$ ip route default via 192.168.1.1 dev eth0 proto static 192.168.1.0/24 dev eth0 proto kernel scope link src 192.168.1.2
That doesn't look as familiar as the netstat report to these old eyes, but it must be conceded that it is usefully informative and highly readable.
A lot of reading, then some judicious fiddling, cannot fail to be educational - and possibly successful, in the end. I think we'd enjoy some questions along the way. You never know what cobwebs they could dust off.
Help, will be GREATLY appeciated.
Trying to get new internet access for when the 2G network was gone has been a real struggle. At this location only 2 options are availible, NBN satelite and 4G mobile broadband, unfortunately there is little information anywhere on how to configure either of them for linux. I tried satelite NBN but could not get ANY kind of reliable connection. A 4G dongle will work on linux but I could find NO config information at all and it appears plenty have tried and failed. THe current solution has been adopted as it only means setting up ethernet ports and doing bit of routing.
If there's no firewall functionality on the 4G modem, then you'll have to climb the networking learning curve, and what's linux for, but for having a fiddle - if you don't mind having to restore to base settings a couple of times while figuring it out. (The "ip route restore" command might be useful there.)
Erik
Thanks for your input its been most helpfull, a couple of comments, I was a complex systems technician for almost 30 years, this has left me with a strong distaste for unnecasary complexity, also personally i LIKE to understand how everything I use works. On this problem as usuall, I am selling my self short on my knowledge of Linux networking (Note 1), I have actual done my own gateway machine with NAT and a firewall and while the DLink will do everything you said, trying to get it to replicate my gateway machine is not something I will find easy to do. I do know though the Dlink can be set in "pass through" mode where it only acts as a 4G reciever, connecting when the device is powered up, leaving me the only thing is changing the routing in my gateway machine, something that IS a WELL KNOWN (although not as yet by me) solution. As I was a tech a very long time I have NO fear of learning anything new................ I will put up what I have done to get it working in case it helps someone else Note 1: One will NEVER learn anything unless one is willing to listen. Lindsay