networking assistance!

[super gnu]

ok so i have a stupidly non-standard network setup here. stupid because networking isnt something i know much about, so i should have just stuck with the standard setup..


so, i have 3 machines. main workstation is connected to router via ethernet (gigabit port on machine, but router is only 100 megabit. )

in main machine i have a dual port 10gb infiniband card.

until recently i had a single second machine connected via infiniband to the main machine..


worked fine.


ive now added a second machine, connected via infiniband to the second port on the main machine.

this means of course, in my setup i have 3 subnets. one router to main machine, one main machine to second machine, and one, main machine to third machine.


issue is, the third machine. since adding it, i can remote desktop to it no problem, but i cannot access any of the shared drives on the main machine. i can see the main machine in the network, but if i double click it, or attempt to access the shared drives, it says cannot access this machine blah blah.

when i run the troubleshooter it says my third machine has an invalid ip setup. quite how i can remote desktop into it in this case is a mystery to me.

i run the troubleshooter repair, but it doesnt fix it.


now, if this is an infiniband issue, i dont expect to get much help, its so obscure to use it on windows, (but its cheap and damn fast)

however if its just a case of setting my ip addresses, subnet masks and default gateways correctly, maybe someone can advise.. i have no idea what to use, specifically for subnet masks and default gateway, dns etc.etc.. its all nonsense to me. i usually just let it do auto settings.

[Morne]

Are you using the same username and password on 3 machines?
If not, maybe its as simple as creating a user on the main machine for the 3rd machine, so that the 3rd machine have access to the main?

Check the ip's of all 3 machines, what is it and what's the gateway?

[super gnu]

all 3 have same username and password and admin privileges.

ok here are the details via ipconfig:




main machine

ethernet connection (connected to router) :

ip: 169.254.228.151
subnet mask: 255.255.0.0
default gateway: not listed


infiniband port 1 (to second machine)

ip: 169.254.231.125
subnet mask 255.255.0.0
default gateway: not listed

infiniband port 2 (to third machine)


ip: 192.168.0.101
subnet mask 255.255.255.0
default gateway: 192.168.0.1


Second Machine (works fine)

ip 169.254.28.224
subnet mask: 255.255.0.0
default gateway: not listed


third machine (the problem one)

ip: 169.254.194.128
subnet mask: 255.255.0.0
default gateway: unlisted.



those are all automatic settings. seem rather screwy to me, but i have no idea what im going with this stuff.,

[super gnu]

hmph.. just done the latest of many restarts.. and now its working.. go figure. ip setup looks identical to before.


could anyone maybe advise a set of manual settings i could use for the 3 machines, so i dont have to rely on auto every time the machine starts? maybe it would be more reliable.

[Morne]

Try a subnet of 255.255.255.0 on all of them and an IP Range of
Main PC 192.168.0.101
2nd PC 192.168.0.102
3rd PC 192.168.0.103

The problem could come in with the Gateway which from the sounds of it is 192.168.0.1

If you check you router, that should be giving out the IP ranges etc. The internal address of the router sounds like it could be 192.168.0.1 and the external address will be whatever you get from your ISP (which has nothing to do with the internal IP)
I'm not certain how the infiniband is getting its range, if that is also coming from the router...

The Gateway (and DNS) is the thing that lets you connect to the internet

[super gnu]

ok well infiniband uses a subnet manager (openSM) running on my main PC. when i switch on one of the slave machines, i have to restart openSM for the new machine to connect.


so i expect that complicates things horribly.

im using the openfabrics IP over infiniband (ipoib) drivers for my infiniband cards.

wrt setting the subnet manually, shouldnt each subnet have a different subnet mask? or doesnt it work like that.?


and, just in case you are wondering whatthe hell im using infiniband for..? i got all 3 cards for £90.. plus another £60 for the cables. the equivalent 10gb ethernet cards are *rather* more expensive.

[Morne]

Your subnets should all be the same and for only 3 machines, the easiest is 255.255.255.0
That basically means that you can have 254 devices with IP's on "YOUR" single network
As soon as you mess with your subnet, for example 255.255.0.0 you can have 254 X 254 devices on different networks

I would simplify it and just use 255.255.255.0

So then an ip range would be for example 192.168.0.X where x can be anything from 1 to 254 where 1 is usually your gateway (in this case the router)
So then the ip range will be:
192.168.0.1
192.168.0.2
192.168.0.3
192.168.0.4
.....
.....
.....
all the way to
192.168.0.254

As soon as you change the 2nd last digit to someting different, for example 192.168.1.1, then that ip is on a different subnet or in laymens terms "on a different network"

[Jason Stewart]

I am not familiar with infiniband but I would first make sure that the ranges don't overlap. I would set the main PC to have a static IP outside the range of the router and then set the 2 additional pcs to also use static IPs outside of the routers range. For example if your router is 192.168.1.1 then it is likely giving out 192.168.1.2-255, set the main pc to 192.168.2.1 and PC2 and PC3 to 192.168.2.2 and 192.168.2.3 respectively. What I imagine is happening is that another device on the network is picking up an IP in the range that the main PC is handing out and then when you start PC2 or PC3 it had that one and everything gets screwy.

Alternatively you can reserve some IPs on your router for these machines and use the same subnet, everything else is basically the same but the 2nd to last number in the IPs will match the router.

Not only is this low maintenance but its easy to remote desktop just by using the IPs, you will always know what PC is on what IP.