mixed network...

[FrancisBacon]

hey all

wd someone be able to explain the situation: i have a HP laptop (Windows
Me), a MAC (OS/X) and a PC (Win98). I have tried to put them on a network -
now i can ping between laptop and MAC - but the PC cannot ping nor does it
reply to pings. To do file transfer between MAC and laptop, i have to use
FTP program but the speed is slow (100kbps - 1 Mbps)and delay between file
ending and next file transfer starting is a lot (30s - 1min). The PC is not
seen on network at all --- any suggestions, please???

thanx a lot ...

 

[BLH]

hey all

wd someone be able to explain the situation: i have a HP laptop (Windows
Me), a MAC (OS/X) and a PC (Win98). I have tried to put them on a network -
now i can ping between laptop and MAC - but the PC cannot ping nor does it
reply to pings. To do file transfer between MAC and laptop, i have to use
FTP program but the speed is slow (100kbps - 1 Mbps)and delay between file
ending and next file transfer starting is a lot (30s - 1min). The PC is not
seen on network at all --- any suggestions, please???

thanx a lot ...

Bit more info please...

How are the devices connected - I assume ethernet but do you have a
hub or switch?

Are you getting a green light for the PC connection?

Do you have the right cables? (ethernet crossover for PC-PC or
straight through for PC-Hub)

What IP addresses are you using - are they all on the same subnet?

If you have a hub are all devices set to half duplex? (a duplex
mismatch can cause severe performance problems - constant collisions).

Are you sure the PC's NIC is OK?

BLH

 

[FrancisBacon]

thanx for response - the network is Ethernet - switched hub used (SMC) - the
lights are all lit up to show connection - straight-through cables for hub -
using the computers on same IP subnet (192.168.1.0/24) - however, the duplex
is issue is not known - pls inform me abt that - any suggestions???

thanx

 

[BLH]

thanx for response - the network is Ethernet - switched hub used (SMC) - the
lights are all lit up to show connection - straight-through cables for hub -
using the computers on same IP subnet (192.168.1.0/24) - however, the duplex
is issue is not known - pls inform me abt that - any suggestions???

thanx

[snip earlier bits.]

When connecting to an ethernet network the nic can usually be
configured for half duplex, full duplex or auto-negotiate. Half duplex
is used when connecting on shared media like a hub, full duplex is
when point to point (PC-PC or PC-switch port). In half duplex the
sending device listens for any other devices on the media before
sending, in full duplex both devices can send and receive at the same
time because there should only be 2 devices on the wire. If the
settings are mismatched the full duplex device will send without
listening and therefore cause collisions on the wire. This means that
the half duplex device will stop and retry whilst the full duplex
device will assume that it's packet has been sent. Eventually the
packets will get through as the half duplex device will be able to
send once the full duplex device has stopped and the lost packets from
the full duplex device will be recovered by the TCP protocol but not
before multiple retries and collisions thus causing a severe loss of
performance.

Auto negotiate is the biggest cause of this problem where NICs do not
detect the correct settings. Auto negotiate should detect both the
duplex and speed - it's possible that you have one device that is at
10Mbps whilst the others are at 100Mbps (or vice versa).

BLH

 

[FrancisBacon]

thanx a lot ... it was great help ...

"FrancisBacon" <[email protected]> wrote in message

thanx for response - the network is Ethernet - switched hub used (SMC) - the
lights are all lit up to show connection - straight-through cables for hub -
using the computers on same IP subnet (192.168.1.0/24) - however, the duplex
is issue is not known - pls inform me abt that - any suggestions???

thanx

[snip earlier bits.]

When connecting to an ethernet network the nic can usually be
configured for half duplex, full duplex or auto-negotiate. Half duplex
is used when connecting on shared media like a hub, full duplex is
when point to point (PC-PC or PC-switch port). In half duplex the
sending device listens for any other devices on the media before
sending, in full duplex both devices can send and receive at the same
time because there should only be 2 devices on the wire. If the
settings are mismatched the full duplex device will send without
listening and therefore cause collisions on the wire. This means that
the half duplex device will stop and retry whilst the full duplex
device will assume that it's packet has been sent. Eventually the
packets will get through as the half duplex device will be able to
send once the full duplex device has stopped and the lost packets from
the full duplex device will be recovered by the TCP protocol but not
before multiple retries and collisions thus causing a severe loss of
performance.

Auto negotiate is the biggest cause of this problem where NICs do not
detect the correct settings. Auto negotiate should detect both the
duplex and speed - it's possible that you have one device that is at
10Mbps whilst the others are at 100Mbps (or vice versa).

BLH