100BaseT

I have two machines setup to run at 100BaseT through a powerconnect 2224 switch. both NIC settings reflect 100Base:

Code:
bge0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
        options=9b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM>
        ether 00 06 5b f8 33 e3
        inet 192.168.2.101 netmask 0xfffffffc broadcast 192.168.2.103
        media: Ethernet autoselect (100baseTX <full-duplex>)
        status: active
and

Code:
sis0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
        options=8<VLAN_MTU>
        ether 00 e0 18 d3 20 95
        inet 192.168.2.102 netmask 0xfffffffc broadcast 192.168.2.103
        media: Ethernet 100baseTX <full-duplex>
        status: active

both cards indicate a 100Base link on the nic the card Led and the switch also shows a 100Base link on both ports.

If I ftp from one machine to the other, I only get a 10meg max transfer.
Incidentally, tcpdump also sees this as a 10MB link:

tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on bge0, link-type EN10MB (Ethernet), capture size 96 bytes


any suggestions on why this is?
 
Check the switch and see if the speed/duplex matches. Sometimes the auto negotiation screws up and you end up with half-duplex.
 
thanks dice,
yes, this particular switch basically gives no options to configure since it isnt managed. Both LEDS on each or all ports for that matter indicate 100Base. if i set the NIC cards to half duplex the switch also reflects this change. it shows the port speed set to 10.
perhaps this switch may be faulty?


does anyone else run the powerconnect 2224 with this problem?
 
ggf said:
... if i set the NIC cards to half duplex the switch also reflects this change. it shows the port speed set to 10. ...
perhaps this switch may be faulty?
...

The next thing I would check was my cabling. Preferably with a cable tester. Length, too. I took a quick look at the manual for the 2224 et. al.; that's what Dell suggests too (Table 2-1. Basic Troubleshooting).

Hope that helps.
 
What do you mean with "...only get a 10meg max transfer..."? 10 Megabytes/sec or 10 Megabits/sec. On a 100MBit fast ethernet link 10 Megabytes/sec means nearly maximum.

When tcpdump says "link-type EN10MB" on a 100MBit link this is also normal. I guess this is what libpcap reports.

cheers,
honk
 
tcpdump reports that on every NIC, even gigabit NICs.

Code:
em0:
	media: Ethernet autoselect (1000baseT <full-duplex>)

Code:
# tcpdump -i em0
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on em0, link-type EN10MB (Ethernet), capture size 96 bytes
 
thanks for the feedback,

I figured tcpdump would have been indicative of the port speed since it was showing 10MB.

the ftp speed was 10Mb.

with a powercycle on the switch ftp came back to 10MB.
perhaps a faulty switch..
 
yes, sis0 was set by hand.
on auto, it detects 100baseTX.

I did a test, set it to half duplex then back to full to see if it made any change. it seems like a faulty switch. after a power cycle the proper speed comes back. after a few days it will happen again...its an ebay switch..
 
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