Very small network question...

Hello group,

I have several questions that someone with more networking experience
may be able to help me with. I am developing an embedded software
application and the target board can use an NFS mount and also download
it's kernel over TFTP (using U-Boot). Normally my set-up is at my work
place so I never see problems. Now I am trying to reproduce something
similar to my work environment at home.

My 'network' looks like this:

- a host PC running SuSE 9.3 with static IP.
- a five port switch (connected to the host PC and target board).
- an Ethernet-enabled target board with a static IP.

With this configuration I have no access to either the Internet or any
other network, just what I describe above.

The output from ifconfig on the host PC looks like this:

eth0 Link encap:Ethernet HWaddr 00:0C:6E:7E:39:49
inet addr:192.168.50.67 Bcast:192.168.50.255
Mask:255.255.255.0
inet6 addr: fe80::20c:6eff:fe7e:3949/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:35 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 b) TX bytes:5831 (5.6 Kb)
Interrupt:193 Base address:0x4400

lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:138 errors:0 dropped:0 overruns:0 frame:0
TX packets:138 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:8987 (8.7 Kb) TX bytes:8987 (8.7 Kb)

I read a posting that gave me the idea to set the gateway to 192.1.1.1
I don't know enough about networking to know if this is sensible but I
tried it
just in case I got lucky (working in limited time on my day off and I
am getting
sort of desperate).

The result I got was:

nbryan@linux:~> ping 192.168.42.31
PING 192.168.42.31 (192.168.42.31) 56(84) bytes of data.
>From 192.168.50.67: icmp_seq=2 Destination Host Unreachable
>From 192.168.50.67 icmp_seq=2 Destination Host Unreachable
>From 192.168.50.67 icmp_seq=3 Destination Host Unreachable
>From 192.168.50.67 icmp_seq=4 Destination Host Unreachable
etc..

So, I need a hint or two.

1) Is what I am trying to achieve possible as I am really only using a
point to point
connection from my PC to the target board, via the switch, I expect it
should just 'work'.
I was told by a work colleague that I need the switch *OR* a crossover
cable.
Is this correct?

2) Most of the settings on my host PC I am happy with. Static IP is
local and unlikely to clash with anything else as it is the only thing
connected! Sub-net mask shouldn't make much difference so I used the
default 255.255.255.0. What about DNS which I believe makes no sense
in my configuration. And also the Gateway! This is the only machine on
the network without exteranl Internet access so what would be the role
of a Gateway?

Thanks for any help offered.

Regards, Neil.

Hello,

to connect two computers directly you need a crossover cable.
If you have something between them (like a switch or hub) you need 'normal'
patch cables. But you could also use the "uplink" port of your hub with a
crossover cable.

Crossover: some wires are crossed
Uplink: the same wires are crossed
Together it works - it is only crossed two times :-)


The gateway question:

You have to set the gateway ONLY if you have a gateway in your network.
Routers may also have gateway functionality. If you don't have one you
mustn't set a gateway in your network settings.

If your computers are in the same subnet (255.255.255.0) on the same ip
range (like your 192.168.50.xxx) you won't use your gateway anyway, so it
doesn't matter if you set one or not. But disable it to be sure.

Generally your network settings seem correct, at least I can't see any
mistake there.

Hope this helps,

Sebastian


<(E-Mail Removed)> schrieb im Newsbeitrag
news:(E-Mail Removed) oups.com...
> Hello group,
>
> I have several questions that someone with more networking experience
> may be able to help me with. I am developing an embedded software
> application and the target board can use an NFS mount and also download
> it's kernel over TFTP (using U-Boot). Normally my set-up is at my work
> place so I never see problems. Now I am trying to reproduce something
> similar to my work environment at home.
>
> My 'network' looks like this:
>
> - a host PC running SuSE 9.3 with static IP.
> - a five port switch (connected to the host PC and target board).
> - an Ethernet-enabled target board with a static IP.
>
> With this configuration I have no access to either the Internet or any
> other network, just what I describe above.
>
> The output from ifconfig on the host PC looks like this:
>
> eth0 Link encap:Ethernet HWaddr 00:0C:6E:7E:39:49
> inet addr:192.168.50.67 Bcast:192.168.50.255
> Mask:255.255.255.0
> inet6 addr: fe80::20c:6eff:fe7e:3949/64 Scope:Link
> UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
> RX packets:0 errors:0 dropped:0 overruns:0 frame:0
> TX packets:35 errors:0 dropped:0 overruns:0 carrier:0
> collisions:0 txqueuelen:1000
> RX bytes:0 (0.0 b) TX bytes:5831 (5.6 Kb)
> Interrupt:193 Base address:0x4400
>
> lo Link encap:Local Loopback
> inet addr:127.0.0.1 Mask:255.0.0.0
> inet6 addr: ::1/128 Scope:Host
> UP LOOPBACK RUNNING MTU:16436 Metric:1
> RX packets:138 errors:0 dropped:0 overruns:0 frame:0
> TX packets:138 errors:0 dropped:0 overruns:0 carrier:0
> collisions:0 txqueuelen:0
> RX bytes:8987 (8.7 Kb) TX bytes:8987 (8.7 Kb)
>
> I read a posting that gave me the idea to set the gateway to 192.1.1.1
> I don't know enough about networking to know if this is sensible but I
> tried it
> just in case I got lucky (working in limited time on my day off and I
> am getting
> sort of desperate).
>
> The result I got was:
>
> nbryan@linux:~> ping 192.168.42.31
> PING 192.168.42.31 (192.168.42.31) 56(84) bytes of data.
> >From 192.168.50.67: icmp_seq=2 Destination Host Unreachable
> >From 192.168.50.67 icmp_seq=2 Destination Host Unreachable
> >From 192.168.50.67 icmp_seq=3 Destination Host Unreachable
> >From 192.168.50.67 icmp_seq=4 Destination Host Unreachable
> etc..
>
> So, I need a hint or two.
>
> 1) Is what I am trying to achieve possible as I am really only using a
> point to point
> connection from my PC to the target board, via the switch, I expect it
> should just 'work'.
> I was told by a work colleague that I need the switch *OR* a crossover
> cable.
> Is this correct?
>
> 2) Most of the settings on my host PC I am happy with. Static IP is
> local and unlikely to clash with anything else as it is the only thing
> connected! Sub-net mask shouldn't make much difference so I used the
> default 255.255.255.0. What about DNS which I believe makes no sense
> in my configuration. And also the Gateway! This is the only machine on
> the network without exteranl Internet access so what would be the role
> of a Gateway?
>
> Thanks for any help offered.
>
> Regards, Neil.
>

Sebastian wrote:
> Hello,
>
> to connect two computers directly you need a crossover cable.
> If you have something between them (like a switch or hub) you need 'normal'
> patch cables. But you could also use the "uplink" port of your hub with a
> crossover cable.
>
> Crossover: some wires are crossed
> Uplink: the same wires are crossed
> Together it works - it is only crossed two times :-)
>
>
> The gateway question:
>
> You have to set the gateway ONLY if you have a gateway in your network.
> Routers may also have gateway functionality. If you don't have one you
> mustn't set a gateway in your network settings.
>
> If your computers are in the same subnet (255.255.255.0) on the same ip

> range (like your 192.168.50.xxx) you won't use your gateway anyway, so it
> doesn't matter if you set one or not. But disable it to be sure.
>
> Generally your network settings seem correct, at least I can't see any
> mistake there.
>
> Hope this helps,
>
> Sebastian
>
>
> <(E-Mail Removed)> schrieb im Newsbeitrag
> news:(E-Mail Removed) oups.com...
> > Hello group,
> >
> > I have several questions that someone with more networking experience
> > may be able to help me with. I am developing an embedded software
> > application and the target board can use an NFS mount and also download
> > it's kernel over TFTP (using U-Boot). Normally my set-up is at my work
> > place so I never see problems. Now I am trying to reproduce something
> > similar to my work environment at home.
> >
> > My 'network' looks like this:
> >
> > - a host PC running SuSE 9.3 with static IP.
> > - a five port switch (connected to the host PC and target board).
> > - an Ethernet-enabled target board with a static IP.
> >
> > With this configuration I have no access to either the Internet or any
> > other network, just what I describe above.
> >
> > The output from ifconfig on the host PC looks like this:
> >
> > eth0 Link encap:Ethernet HWaddr 00:0C:6E:7E:39:49
> > inet addr:192.168.50.67 Bcast:192.168.50.255
> > Mask:255.255.255.0
> > inet6 addr: fe80::20c:6eff:fe7e:3949/64 Scope:Link
> > UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
> > RX packets:0 errors:0 dropped:0 overruns:0 frame:0
> > TX packets:35 errors:0 dropped:0 overruns:0 carrier:0
> > collisions:0 txqueuelen:1000
> > RX bytes:0 (0.0 b) TX bytes:5831 (5.6 Kb)
> > Interrupt:193 Base address:0x4400
> >
> > lo Link encap:Local Loopback
> > inet addr:127.0.0.1 Mask:255.0.0.0
> > inet6 addr: ::1/128 Scope:Host
> > UP LOOPBACK RUNNING MTU:16436 Metric:1
> > RX packets:138 errors:0 dropped:0 overruns:0 frame:0
> > TX packets:138 errors:0 dropped:0 overruns:0 carrier:0
> > collisions:0 txqueuelen:0
> > RX bytes:8987 (8.7 Kb) TX bytes:8987 (8.7 Kb)
> >
> > I read a posting that gave me the idea to set the gateway to 192.1.1.1
> > I don't know enough about networking to know if this is sensible but I
> > tried it
> > just in case I got lucky (working in limited time on my day off and I
> > am getting
> > sort of desperate).
> >
> > The result I got was:
> >
> > nbryan@linux:~> ping 192.168.42.31
> > PING 192.168.42.31 (192.168.42.31) 56(84) bytes of data.
> > >From 192.168.50.67: icmp_seq=2 Destination Host Unreachable
> > >From 192.168.50.67 icmp_seq=2 Destination Host Unreachable
> > >From 192.168.50.67 icmp_seq=3 Destination Host Unreachable
> > >From 192.168.50.67 icmp_seq=4 Destination Host Unreachable
> > etc..
> >
> > So, I need a hint or two.
> >
> > 1) Is what I am trying to achieve possible as I am really only using a
> > point to point
> > connection from my PC to the target board, via the switch, I expect it
> > should just 'work'.
> > I was told by a work colleague that I need the switch *OR* a crossover
> > cable.
> > Is this correct?
> >
> > 2) Most of the settings on my host PC I am happy with. Static IP is
> > local and unlikely to clash with anything else as it is the only thing
> > connected! Sub-net mask shouldn't make much difference so I used the
> > default 255.255.255.0. What about DNS which I believe makes no sense
> > in my configuration. And also the Gateway! This is the only machine on
> > the network without exteranl Internet access so what would be the role
> > of a Gateway?
> >
> > Thanks for any help offered.
> >
> > Regards, Neil.
> >

Thank you for taking the time to reply Sebastian!

I had a thought that my IP ranges(!) may not work in this small
network.

My host IP is 192.168.50.67.
The target IP was 192.168.42.31.

I have changed the target IP to be 192.168.50.135 as this matches the
setup I use at work. I was concerned about using 192.168.42.xx as this
may not be in the same range as my host? Unfortunately I still
experience the 'destination unreachable' error when I try to ping my
target. I removed the default gateway setting I had applied and this
field is now blank ( I am referring to YaST configuration screen
here).

So, I am still at a loss. Are there any other diagnostics I can apply
to try and understand what is going wrong? The problem with the
pass/fail situation I have at moment is that I cannot incrementaly fix
it. I like to make decisions based upon data obtained from performing
tests. If I ping, it fails, but I don't know why and this is
frustrating. If there were other tools besides ping that could help me
understand what my host can 'see' on my mini-network, I may stand more
of a chance to succeed.

Once again, thank you for your time.

Best regards, Neil Bryan.

(E-Mail Removed) wrote:
> Hello group,
>
> I have several questions that someone with more networking experience
> may be able to help me with. I am developing an embedded software
> application and the target board can use an NFS mount and also download
> it's kernel over TFTP (using U-Boot). Normally my set-up is at my work
> place so I never see problems. Now I am trying to reproduce something
> similar to my work environment at home.
>
> My 'network' looks like this:
>
> - a host PC running SuSE 9.3 with static IP.
> - a five port switch (connected to the host PC and target board).
> - an Ethernet-enabled target board with a static IP.
>
> With this configuration I have no access to either the Internet or any
> other network, just what I describe above.
>
> The output from ifconfig on the host PC looks like this:
>
> eth0 Link encap:Ethernet HWaddr 00:0C:6E:7E:39:49
> inet addr:192.168.50.67 Bcast:192.168.50.255
> Mask:255.255.255.0
> inet6 addr: fe80::20c:6eff:fe7e:3949/64 Scope:Link
> UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
> RX packets:0 errors:0 dropped:0 overruns:0 frame:0
> TX packets:35 errors:0 dropped:0 overruns:0 carrier:0
> collisions:0 txqueuelen:1000
> RX bytes:0 (0.0 b) TX bytes:5831 (5.6 Kb)
> Interrupt:193 Base address:0x4400
>
> lo Link encap:Local Loopback
> inet addr:127.0.0.1 Mask:255.0.0.0
> inet6 addr: ::1/128 Scope:Host
> UP LOOPBACK RUNNING MTU:16436 Metric:1
> RX packets:138 errors:0 dropped:0 overruns:0 frame:0
> TX packets:138 errors:0 dropped:0 overruns:0 carrier:0
> collisions:0 txqueuelen:0
> RX bytes:8987 (8.7 Kb) TX bytes:8987 (8.7 Kb)
>
> I read a posting that gave me the idea to set the gateway to 192.1.1.1
> I don't know enough about networking to know if this is sensible but I
> tried it
> just in case I got lucky (working in limited time on my day off and I
> am getting
> sort of desperate).
>
> The result I got was:
>
> nbryan@linux:~> ping 192.168.42.31
> PING 192.168.42.31 (192.168.42.31) 56(84) bytes of data.
>>From 192.168.50.67: icmp_seq=2 Destination Host Unreachable
>>From 192.168.50.67 icmp_seq=2 Destination Host Unreachable
>>From 192.168.50.67 icmp_seq=3 Destination Host Unreachable
>>From 192.168.50.67 icmp_seq=4 Destination Host Unreachable
> etc..
>
> So, I need a hint or two.
>
> 1) Is what I am trying to achieve possible as I am really only using a
> point to point
> connection from my PC to the target board, via the switch, I expect it
> should just 'work'.
> I was told by a work colleague that I need the switch *OR* a crossover
> cable.
> Is this correct?

If your target board is connected to your PC via the switch, you don't
need to route packets through a gateway. Your problem is that you have
told your PC that the local network is 192.168.50.x but your board is
192.168.42.y so it doesn't know the route. So change your netmask to
255.255.0.0 and you'll be OK. You may have to do something similar on
your target board so that it knows that your PC is on its local network.

Robert

>
> 2) Most of the settings on my host PC I am happy with. Static IP is
> local and unlikely to clash with anything else as it is the only thing
> connected! Sub-net mask shouldn't make much difference so I used the
> default 255.255.255.0. What about DNS which I believe makes no sense
> in my configuration. And also the Gateway! This is the only machine on
> the network without exteranl Internet access so what would be the role
> of a Gateway?
>
> Thanks for any help offered.
>
> Regards, Neil.
>

(E-Mail Removed) wrote:
> Sebastian wrote:
>
>>Hello,
>>
>>to connect two computers directly you need a crossover cable.
>>If you have something between them (like a switch or hub) you need 'normal'
>>patch cables. But you could also use the "uplink" port of your hub with a
>>crossover cable.
>>
>>Crossover: some wires are crossed
>>Uplink: the same wires are crossed
>>Together it works - it is only crossed two times :-)
>>
>>
>>The gateway question:
>>
>>You have to set the gateway ONLY if you have a gateway in your network.
>>Routers may also have gateway functionality. If you don't have one you
>>mustn't set a gateway in your network settings.
>>
>>If your computers are in the same subnet (255.255.255.0) on the same ip
>
>
>>range (like your 192.168.50.xxx) you won't use your gateway anyway, so it
>>doesn't matter if you set one or not. But disable it to be sure.
>>
>>Generally your network settings seem correct, at least I can't see any
>>mistake there.
>>
>>Hope this helps,
>>
>>Sebastian
>>
>>
>><(E-Mail Removed)> schrieb im Newsbeitrag
>>news:(E-Mail Removed) groups.com...
>>
>>>Hello group,
>>>
>>>I have several questions that someone with more networking experience
>>>may be able to help me with. I am developing an embedded software
>>>application and the target board can use an NFS mount and also download
>>>it's kernel over TFTP (using U-Boot). Normally my set-up is at my work
>>>place so I never see problems. Now I am trying to reproduce something
>>>similar to my work environment at home.
>>>
>>>My 'network' looks like this:
>>>
>>>- a host PC running SuSE 9.3 with static IP.
>>>- a five port switch (connected to the host PC and target board).
>>>- an Ethernet-enabled target board with a static IP.
>>>
>>>With this configuration I have no access to either the Internet or any
>>>other network, just what I describe above.
>>>
>>>The output from ifconfig on the host PC looks like this:
>>>
>>>eth0 Link encap:Ethernet HWaddr 00:0C:6E:7E:39:49
>>> inet addr:192.168.50.67 Bcast:192.168.50.255
>>>Mask:255.255.255.0
>>> inet6 addr: fe80::20c:6eff:fe7e:3949/64 Scope:Link
>>> UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
>>> RX packets:0 errors:0 dropped:0 overruns:0 frame:0
>>> TX packets:35 errors:0 dropped:0 overruns:0 carrier:0
>>> collisions:0 txqueuelen:1000
>>> RX bytes:0 (0.0 b) TX bytes:5831 (5.6 Kb)
>>> Interrupt:193 Base address:0x4400
>>>
>>>lo Link encap:Local Loopback
>>> inet addr:127.0.0.1 Mask:255.0.0.0
>>> inet6 addr: ::1/128 Scope:Host
>>> UP LOOPBACK RUNNING MTU:16436 Metric:1
>>> RX packets:138 errors:0 dropped:0 overruns:0 frame:0
>>> TX packets:138 errors:0 dropped:0 overruns:0 carrier:0
>>> collisions:0 txqueuelen:0
>>> RX bytes:8987 (8.7 Kb) TX bytes:8987 (8.7 Kb)
>>>
>>>I read a posting that gave me the idea to set the gateway to 192.1.1.1
>>>I don't know enough about networking to know if this is sensible but I
>>>tried it
>>>just in case I got lucky (working in limited time on my day off and I
>>>am getting
>>>sort of desperate).
>>>
>>>The result I got was:
>>>
>>>nbryan@linux:~> ping 192.168.42.31
>>>PING 192.168.42.31 (192.168.42.31) 56(84) bytes of data.
>>>>From 192.168.50.67: icmp_seq=2 Destination Host Unreachable
>>>>From 192.168.50.67 icmp_seq=2 Destination Host Unreachable
>>>>From 192.168.50.67 icmp_seq=3 Destination Host Unreachable
>>>>From 192.168.50.67 icmp_seq=4 Destination Host Unreachable
>>>etc..
>>>
>>>So, I need a hint or two.
>>>
>>>1) Is what I am trying to achieve possible as I am really only using a
>>>point to point
>>>connection from my PC to the target board, via the switch, I expect it
>>>should just 'work'.
>>>I was told by a work colleague that I need the switch *OR* a crossover
>>>cable.
>>>Is this correct?
>>>
>>>2) Most of the settings on my host PC I am happy with. Static IP is
>>>local and unlikely to clash with anything else as it is the only thing
>>>connected! Sub-net mask shouldn't make much difference so I used the
>>>default 255.255.255.0. What about DNS which I believe makes no sense
>>>in my configuration. And also the Gateway! This is the only machine on
>>>the network without exteranl Internet access so what would be the role
>>>of a Gateway?
>>>
>>>Thanks for any help offered.
>>>
>>>Regards, Neil.
>>>
>
>
> Thank you for taking the time to reply Sebastian!
>
> I had a thought that my IP ranges(!) may not work in this small
> network.
>
> My host IP is 192.168.50.67.
> The target IP was 192.168.42.31.
>
> I have changed the target IP to be 192.168.50.135 as this matches the
> setup I use at work. I was concerned about using 192.168.42.xx as this
> may not be in the same range as my host? Unfortunately I still
> experience the 'destination unreachable' error when I try to ping my
> target. I removed the default gateway setting I had applied and this
> field is now blank ( I am referring to YaST configuration screen
> here).
>
> So, I am still at a loss. Are there any other diagnostics I can apply
> to try and understand what is going wrong? The problem with the
> pass/fail situation I have at moment is that I cannot incrementaly fix
> it. I like to make decisions based upon data obtained from performing
> tests. If I ping, it fails, but I don't know why and this is
> frustrating. If there were other tools besides ping that could help me
> understand what my host can 'see' on my mini-network, I may stand more
> of a chance to succeed.


You should not reach the host directly in another subnet.

If the target host is in another subnet, you need a gateway
host in the local subnet, and it needs access to the target net.

Put both hosts into the same subnet if you want to
run them in a LAN.

Your subnets are now 192.168.50.0/24 (/24 means netmask 255.255.255.0)
and 192.168.42.0/24.

Change both hosts to the 192.168.42.x or 192.168.50.x,
or widen the netmask to cover both: /16 = 255.255.0.0

A standard diagnostic in routing problems is:

route -n

It prints your routing table telling which IP addresses
your sent packets can reach and which way they will be sent.

HTH

--

Tauno Voipio
tauno voipio (at) iki fi

(E-Mail Removed) writes:

>Hello group,

>I have several questions that someone with more networking experience
>may be able to help me with. I am developing an embedded software
>application and the target board can use an NFS mount and also download
>it's kernel over TFTP (using U-Boot). Normally my set-up is at my work
>place so I never see problems. Now I am trying to reproduce something
>similar to my work environment at home.

>My 'network' looks like this:

>- a host PC running SuSE 9.3 with static IP.
>- a five port switch (connected to the host PC and target board).
>- an Ethernet-enabled target board with a static IP.

>With this configuration I have no access to either the Internet or any
>other network, just what I describe above.

Do you want access to the Internet? It is not clear whether you are
describing the situation or the desired situation.


>The output from ifconfig on the host PC looks like this:

>eth0 Link encap:Ethernet HWaddr 00:0C:6E:7E:39:49
> inet addr:192.168.50.67 Bcast:192.168.50.255
>Mask:255.255.255.0
> inet6 addr: fe80::20c:6eff:fe7e:3949/64 Scope:Link
> UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
> RX packets:0 errors:0 dropped:0 overruns:0 frame:0
> TX packets:35 errors:0 dropped:0 overruns:0 carrier:0
> collisions:0 txqueuelen:1000
> RX bytes:0 (0.0 b) TX bytes:5831 (5.6 Kb)
> Interrupt:193 Base address:0x4400

>lo Link encap:Local Loopback
> inet addr:127.0.0.1 Mask:255.0.0.0
> inet6 addr: ::1/128 Scope:Host
> UP LOOPBACK RUNNING MTU:16436 Metric:1
> RX packets:138 errors:0 dropped:0 overruns:0 frame:0
> TX packets:138 errors:0 dropped:0 overruns:0 carrier:0
> collisions:0 txqueuelen:0
> RX bytes:8987 (8.7 Kb) TX bytes:8987 (8.7 Kb)

>I read a posting that gave me the idea to set the gateway to 192.1.1.1

You have no need for a gateway. You just have two machines that you want to
connect together. Just put in a direct enetry (host entry) into the routing
table.
route add -host 192.168.50.68 eth0
Or wahtever the address of the card is. (Why in the world did you pick that
IP address. Nothing wrong with it, but it is weird to pick 50.67 as the
address of a machine when you have everything from
0.1 to 255.254 to choose from.

>I don't know enough about networking to know if this is sensible but I
>tried it
>just in case I got lucky (working in limited time on my day off and I
>am getting
>sort of desperate).

That address for a gateway is useless since it is not on the same subnet
(192.168.50.0/24) that your machine is on, but again you do not need a
gateway.


>The result I got was:

>nbryan@linux:~> ping 192.168.42.31
>PING 192.168.42.31 (192.168.42.31) 56(84) bytes of data.

What???? And then you pick some other random number for the IP of the
board?
Why 42.31???? Weirder and weirder.
Put it on th esame subnet at least as the computer. (50.x)


>>From 192.168.50.67: icmp_seq=2 Destination Host Unreachable
>>From 192.168.50.67 icmp_seq=2 Destination Host Unreachable
>>From 192.168.50.67 icmp_seq=3 Destination Host Unreachable
>>From 192.168.50.67 icmp_seq=4 Destination Host Unreachable
>etc..

>So, I need a hint or two.

>1) Is what I am trying to achieve possible as I am really only using a
>point to point
>connection from my PC to the target board, via the switch, I expect it
>should just 'work'.

If you chose your IP addresses a little less randomly it would just work.


>I was told by a work colleague that I need the switch *OR* a crossover
>cable.
>Is this correct?

Well, what he means is that for you to connect the two together you need
eitehr a switch or a router or a crossover (to connect them directly with a
wire from one to the other) but you already have a router, so not you do
not need anything else.



>2) Most of the settings on my host PC I am happy with. Static IP is
>local and unlikely to clash with anything else as it is the only thing
>connected! Sub-net mask shouldn't make much difference so I used the

Why do you choose it randomly.

>default 255.255.255.0. What about DNS which I believe makes no sense

Yes, it does matter. 40.37 is not on the same subnet as 50.67.
You could make it work by making the subnet 255.255.0.0, or by choosing the
two IP addresses a bit more non-randomly.

>in my configuration. And also the Gateway! This is the only machine on

No gateway needed. A gateway is used when the two machines are not on the
same subnet and you need a computer that is on the same subnet as you to
send on the packets. I suspect that your router has an address like
192,168.1.1 or .0.1 which again is not on the same subnet as yours.

>the network without exteranl Internet access so what would be the role
>of a Gateway?

None, unless you try really really really hard to mess up your networking.


>Thanks for any help offered.

>Regards, Neil.

Thanks for the time, but steady on on the assumptions! First of all,
the board was shipped with the IP that mapped across from my
192.168.50.xx to the 192.168.42.xx that I showed earlier. Whilst
thinking about the problem I realised that this was probably a bad
thing (please bare in mind that I am *not* a network guru so try not to
roast me until I really ask for it ;-) ) In fact I would go so far as
to say I know f@#^% all about networks and will be brave enough to
admit it. So, I shall ignore the gateway 'cos that's silly in my
application, I have sorted out my subnets and IP ranges and I have
changed the target board IP. It still does not see the target when I
invoke a ping.

As for some backgorund, in this setup I am trying to transfer via TFTP
the Linux kernel image from my host to the target board. Internet
access is certainly not needed.

I feel I must have written my original mail too vaguely.

This is a single PC, with a single switch and a single target board.
Nothing else, that's it. No LANs, WANs or other complications. I hoped
that the configuration would be simple, and I am sure it will be when
it all works, but I don't want to confuse anyone who responds with
information that is very helpful, but not really required.

I shall review all the information that has been provided and perform
some more tests. I shall post the results when I have them. Thanks to
all!

Regards, Neil.