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-   -   3C509B can not connect over TCP/IP (gets DHCP address though) (https://www.linuxquestions.org/questions/linux-hardware-18/3c509b-can-not-connect-over-tcp-ip-gets-dhcp-address-though-378387/)

RSpendl 10-30-2005 02:06 PM

3C509B can not connect over TCP/IP (gets DHCP address though)
 
Hi all,
I am trying to make some use out of a scrap computer (P-150, 48 M RAM) with Ubuntu, but I am stuck with an ISA 3COM 3C509B-TPO card. I have loaded 3c509 module (without any parameters and with xcvr=12,12 (force full-duplex) and xcvr=4,4 (tell it is connected to 10-baseT)), got ifup eth0, which actually obtains the address from dhcp server, can ping local computers and any internet computers, resolve DNS (i.e. ping www-google-com works fine, the packets are not lost - actually, only one in 25 was lost), but
...
I can not make a simple TCP/IP connection even in the local network.

To avoid all other issues (firewall lets all packets in the local network through), I tried a trivial connection with nc:
1. Listen on non-working computer (192-168-0-5 - kant-ipsum-si) with "nc -l -p 3000"
2. Try to connect from 192-168-0-1 (zion-ipsum-si) with "nc 192-168-0-5 3000" (any type abc and Enter)
There is no response at the listener's side, it does not connect nor give any kind of hint that it has received anything (even an error would be a major improvement ;-).

The output from tcpdump -vv is as follows:
tcpdump: listening on eth0, link-type EN10MB (Ethernet), capture size 96 bytes
20:50:57.808873 IP (tos 0x0, ttl 64, id 3841, offset 0, flags [DF], proto 6, length: 60) zion-ipsum-si.33720 > kant-ipsum-si.3000: S [tcp sum ok] 2767605910:2767605910(0) win 5840 <mss 1460,sackOK,timestamp 45965207 0,nop,wscale 2>
(this is when nc tries to connect)

20:51:00.809749 IP (tos 0x0, ttl 64, id 3843, offset 0, flags [DF], proto 6, length: 60) zion-ipsum-si.33720 > kant-ipsum-si.3000: S [tcp sum ok] 2767605910:2767605910(0) win
5840 <mss 1460,sackOK,timestamp 45968208 0,nop,wscale 2>
(when I type "abc" and press Enter)

20:51:02.809644 arp who-has kant-ipsum-si tell zion-ipsum-si
20:51:02.810131 arp reply kant-ipsum-si is-at ff:ff:24:40:f8:58
(when nc is closed by Ctrl-C)


Does anyone has any suggestion what to try? (besides throwing the scrap away and get some life ;-) How could I tell it is some configuration issue or just a faulty NIC? It is puzzling since ping and DNS work without any problems, so I can't see why is "nc" just quiet.

Any suggestions are appreciated.

Thanks,
Robert

uberNUT69 10-30-2005 04:43 PM

I've found these cards to be nothing but reliable on default settings.
Do the same problems occur in half-duplex?
Are you connecting your machines with an n-way switch?

RSpendl 10-30-2005 10:22 PM

It is the same with half-duplex (default) and full-duplex (xcvr=12,12), through the 10/100 Mbps switch or connecting directly to the other computer via crossover cable. I've checked IRQ and it is not shared by any other device, interrupts seem to occur OK (number in /proc/interrupts is increasing gradually).
:confused:

uberNUT69 10-30-2005 11:35 PM

Perhaps these might help
http://www.tldp.org/HOWTO/Ethernet-HOWTO-4.html#ss4.1
http://linuxgazette.net/112/tag/1.html
ftp://ftp.3com.com/pub/nic/3c509/

It's been a while since I played with these old cards.
Last time I remember using them I put 3 in a firewall.
I think I made sure the IO ports and IRQs were all set manually.
Have you disabled any onboard devices to make sure there's no conflict?
The ETHERNET-HOWTO also mentions unmasking IDE interrupts
to avoid dropped packets (with some models, in some cases)

Hope that helps a little.

RSpendl 10-31-2005 06:56 AM

Thanks for all the links, I have fiddeled with settings for a while but
since there was no success, I decided to blow 6 EUR for a new RTL
8139D 10/100 network card and guess what - it worked right away.
Probably the problem was with the card anyway.

Thank you again for your efforts,
Robert


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