Cannot link 2 laptops - please help before I shoot myself!

[Guest johnKFT]

I sort of solved my problem with usb cable - see post below -- in that the usb0 interface now comes up. However I still cannot get the machines to see each other, and I really do not know what I am or am not doing. If I list everything that seems relevant perhaps someone might be able to help me before I go completely demented.

 

1 The usb link cable with Prolific chipset is recognised.

2 Usbnet module seems to find it.

3 I am sure I have the NFS stuff set up OK.

4 I have read everything I can find on the subject.

5 In /etc/sysconfig/network-scripts I seem to have inherited files ifup and ifcfg for an interface called plusb0 and plusb, which is described as being the Prolific chipset thing. However, if I do ifconfig plusb0 I am told the device cannot be found.

6 On instructions from Linux-usb I copied both these files and renamed them ifcfg-usb0 and ifup-usb, since when the usb0 interface comes up on booting. I also put alias usb0 usb in /etc/modules.conf. If I do ifconfig usb0 I get all sorts of correct sounding information.

7 If I do mount <server>:/home /mnt/domestic I get:

mount: RPC; Portmapper failure - RPC. Unable to send.

If I do rpcinfo -p <server> I get:

rpcinfo. Can't contact portmapper: RPC: remote system error - Network unreachable.

8 After doing this /var/log/messages says:

/etc/hotplug/net.agent: NET unregister event not supported

 

The portmapper is running on both machines, as are all the NFS things. I have both machines set up as both server and client, and the behaviour described above happens on both machines.

 

Has anyone any idea what the problem could be? I literally have not the faintest idea what to even blindly try next, never mind constructively explore.

[fuzzylizard]

here is a really dumb question, but are trying to connect the two machines directly or through a hub?

 

If you are trying to do it directly, then you need to use a cross-over cable and not a regular network cable. If you are using a straight ethernet -- rj45 -- cable, then the two machines will never see each other. Regardless of whether the computers are set up correctly.

[Guest johnKFT]

One machine is connected with an A-B cable to a four port usb hub into which are plugged a printer, scanner, webcam and the A-A Prolific USBLINK cable which goes to the other machine. This cable is sold specifically for the purpose of enabling 2 machines to swap files and use the same peripherals, so I assume it is the right thing - it is also stated to be suitable for Linux, and the Linux-usb article I read agreed with this. I assume this is what is called a crossover cable.

 

I just read another post (in Software) last night that said trouble might ensue if you use your website name as the Domain name for the network. I have done this as I assumed that was the right thing. Could that have anything to do with it? Having said that, I just realise that the machine cannot see any of the peripherals on the hub either, so it would seem to point to a problem with using the cable.

 

I have just re-read carefully the article from Linux-usb and I now think my network-scripts are probably wrong. Here they are:

 

/etc/sysconfig/network:-

NETWORKING=yes

FORWARD_IPV4=false

HOSTNAME="navigation.kungfu-tse.net"

DOMAINNAME=kungfu-tse.net

 

etc/sysconfig/network-scripts/ifcfg-usb0:-

DEVICE="usb0"

BOOTPROTO="none"

IPADDR="192.168.1.2"

NETWORK=192.168.1.0

ONBOOT="yes"

NETMASK=""

IPXNETNUM_802_2=""

IPXPRIMARY_802_2="no"

IPXACTIVE_802_2="no"

IPXNETNUM_802_3=""

IPXPRIMARY_802_3="no"

IPXACTIVE_802_3="no"

IPXNETNUM_ETHERII=""

IPXPRIMARY_ETHERII="no"

IPXACTIVE_ETHERII="no"

IPXNETNUM_SNAP=""

IPXPRIMARY_SNAP="no"

IPXACTIVE_SNAP="no"

 

/etc/sysconfig/network-scripts/ifup-usb:-

cd /etc/sysconfig/network-scripts

. network-functions

 

CONFIG=$1

source_config

 

if [ "foo$2" = "fooboot" -a "${ONBOOT}" = "no" ]

then

exit

fi

 

if [ ${BROADCAST} != "" ] ; then

ifconfig ${DEVICE} ${IPADDR} pointopoint ${REMIP} netmask ${NETMASK}

broadcast ${BROADCAST}

else

ifconfig ${DEVICE} ${IPADDR} pointopoint ${REMIP} netmask ${NETMASK}

fi

 

. /etc/sysconfig/network

 

if [ "${GATEWAY}" != "" ]; then

if [ "${GATEWAYDEV}" = "" -o "${GATEWAYDEV}" = "${DEVICE}" ]; then

# set up default gateway

route add default gw ${GATEWAY}

fi

fi

 

/etc/sysconfig/network-scripts/ifup-post $1

 

The ifcfg-usb0 has been written to by something as it is not the same as the one I wrote. I suspect the bit about pointopoint might be wrong as the article mentioned something about this in connection with plusb0 driver (which it says is an old version - which presumably is now taken over by usb0?) It is all very confusing but I hope you or someone might be able to make some sense of it with this extra information.

 

John