Re: 7845i keeps dropping IP connection

["Petem" <petem001@xxxxxxxxx>]

"Jim"  a écrit dans le message de groupe de discussion :
d930cf88-047c-4940-9511-e53277a467e8@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx


> Sometimes you'll find that there's just "something" about a particular
> router that doesn't jive with something on YOUR network but will work
> without a hitch on another network with different components.    Go
> figure!

Totally true, had once a big argument with a network specialist...or so...
telling him that his 3com switch had a non compatible auto negociate with my
DVR so I could not connect it directly to his switch, the only way to make
it work was if I used a small switch (d-link 4 port) between the dvr and
3com switch.

the dvr was setup to 100mb full duplex and the switch was allways detecting
the dvr as 10mb full duplex.. damn it was hell to make him understand that
autonegociate doesnt allways work..after 3 days of email and visit on site
(he didnt want the dlink switch to stay there) he finally reprogram the port
on the switch to be fix at 100mb full duplex..all was well after that..

One other time a customer was using a small network ionterface from dsc to
do local  and outside download for a pc4020 and dsl3 for user..

the customer was complaining that he was not able to connect to the device
during the day.. just at night..
That was very strange.. On site I pluged my laptop and started sniffing the
packet on the network cable that was going to the device..there was about
30mb/s of broadcast packet going to every computer on the network(broadcast
packet are data sent to all device on a network...) But the catch was that
the device was a 10mb/s half duplex old thing.. try to send 30,b/s to a
10mb/s device you will overload it and you wont be able to communicate with
it..
The network guys told me that it was impossible to have that much broadcast
on there network. so I made them download ethereal (now wireshark) and they
were not knowledgable enough to understand what there were looking at..

I had to bring from the shop a laptop I used to debug real nasty problem on
network that had computer associate port sniffer ( A damn good program but a
bit pricey) then with a pie chart diagram of the packet received on that
computer for 10 minute they did understood the obvious..

Know what was all this broadcast stuff.. Radio station.. 5 or 6 people were
listening to some radio station over the internet..all different one. Usely
it should not have created any problem. But here there proxy server for the
network were converting Unicast packets to broadcast packets...(Unicast is a
way to send only one packets over internet and have it restransmit to every
one at once that ask for it..so radio station dont have to send there data
to 30000 pople at once (think of the bandwith needed for that!!!)

So networking is a strange world.. anything and the inverse can happen and
you need some really good alarm tech to understand it..