This is an interesting challenge to which there are a number of solutions. The wording of your question does leave some questions, but I think from context I have an idea what you're trying to do.
I assume these hosts are all on the same physical network segment - e.g. connected to a hub or switch and can ping each other on the 192.168.1.x network without going through a router. In this case, you really want a second network in parallel to the original - a slight nitpick, but relevant to understanding what's happening, I think.
I do think it's likely that Eric Renouf's answer above is hot on the trail - by default iproute2 is likely to add a 32-bit netmask - 255.255.255.255 - which is correct in a number of situations where routing is involved / necessary, such as at a large hosting provider where some machines have several IP addresses, handed out over time. You likely want a 24-bit netmask - 255.255.255.0 - or even a 16-bit, if you truly intend to use the entire 10.170.x.x space.
As an aside, the '.x.x' bit of the addresses is really an important detail here, typically we would describe a network using its' "network address", the bottom address in a particular subnetted range. In this case, your network addresses are 192.168.1.0/24 and 10.170.0.0/16. It's possible to have subnets smaller than class C-sized / 24-bit, where the network address isn't zero. I won't go into too much detail, but strongly suggest investing some time reading about subnetting.
Now that we know to avoid the default netmask, and why, consider:
ip addr del 10.170.0.1 dev eth0
ip addr add 10.170.0.1/16 dev eth0
Repeat on each machine. If you want these configured at boot, also consider adding this line as as post-up command in /etc/network/interfaces.
Hope this helps!