Dan Thanks for your help On 29 Jan, Dan Kolb <dankolb@ox.compsoc.net> wrote:
On Mon, 29 Jan 2001, Dave Williams wrote:
All that follows is based on SuSE 7.0. I am changing our ip address range from 172.19.50.x (255.255.255.0) to 172.16.y.x (255.255.252.0) - reason - more numbers. However, while moving over I need to let machines on both ranges communicate eg. clients printing to print servers etc.
Is this possible?
Presumably, yes. But why can't you keep using 172.19.50.x, but with a subnet mask of 255.255.252.0? The LEA allocated this range and the others in 172.19.x.y are used by other local schools. We all access an LEA proxy so I'd rather use something different.
This will allow you to have 172.19.48.0 -> 172.19.51.255
I'm confused here - I thought 255.255.252.0 would leave 172.19.0.0 to 172.19.3.255
And it'll be easier for you as all you'd have to change is the subnet mask on the machines.
If I set up 2 interfaces on the server (derby) with
ifconfig eth0:0 172.19.50.2 netmask 255.255.255.0 ifconfig eth0:1 172.16.0.2 netmask 255.255.252.0
and turn ip forwarding on with yast, should machines on the 2 ip ranges be able to communicate. eg. ping each other
I've tried it and they don't.
What does "route -n" give?
root@derby:/home/dw > route -n Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 172.19.50.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0 172.16.0.0 0.0.0.0 255.255.252.0 U 0 0 0 eth0 127.0.0.0 0.0.0.0 255.0.0.0 U 0 0
And then I'd presume you'd have to set up the clients to say that if the need to access 172.19.50.0/255.255.255.0, they should route to 172.19.50.2,
How would I do this?
otherwise go to your default gateway (whatever that may be; usually an Internet gateway).
The gateway on each client is set to the relevant IP on Derby.
Am I trying something silly and if not what other steps do I need?
How about "route add 172.16.0.2 netmask 255.255.252.0 dev eth0:1". Or something similar? This gives the error "netmask doesn't make sense with host route"
Thanks again Dave