I have installed a rather long, about 20m, cat5e cable linking my VDSL modem to the rest of the network, and used female, surface-mounted RJ45 connectors also rated for cat5e. The reason is I have a rather bad VDSL signal, and bad internal phone wiring, so wanted to keep the phone cable as short as possible.
Shorter (1m) cat5e patch cables (male-male) complete the circuit at its ends. I added a 5-port 1Gbps D-Link Green switch right next to the modem, and linked the switch to the two other switches, all 1Gbps. The modem is rated for 100Mbps on the LAN ports, so I should get 1Gbps between LAN computers, and 100Mbps toward the Internet. That's OK, my Internet connection is the fastest available at 50Mbps.
I plugged a LaCie Cloudbox to the first switch, and it correctly negotiated 1Gbps speed (Green light on the D-Link switch).
However, the long cat5e cable (female-female) between the first and second Ethernet switches only gives 100Mbps (Orange light on the D-Link), meaning there's a bottleneck between the LaCie Cloudbox and the rest of the devices.
Suspecting either a bad second switch or faulty cables (most of them are used), I tried different cable combinations at each end, and connected a known-good computer at the other end of the long Ethernet cable, still gives 100Mbps.
What could be the reason why I don't get 1Gbps between all the switches?
EDIT FOR CLARITY: Thanks all,
the first switch is D-Link DGS-1005G, revision B1, the second switch is a generic Chinese based on some Realtek chip, the third is another generic Chinese, same kind of chip. Couldn't read the part number as they stuck a heatsink on it.
The female-female cable is 4 pairs, solid core. By the way, it comes from a 1000 feet spool fed from a box, the same kind professional installers use. I wired it following T568B color code.
I switched the first, original cat5e patch cable (4-pair, yellow, wired according to T568B, factory molded) from the D-Link switch to the female plug of the 20m cable with another cat5e patch cable approximately the same length (4-pair, grey, T568B, factory-molded), then another 2m cat5e patch cable (white, T568B) I made by hand from the same length as the 20m cable. I know it's not recommended to use solid-core for patch cable, but I use it as a back-up cable that only sees occasional usage. This cable is known-good for Gbps speed (tested both at home and in university).
No combination succeeded.
Then I switched the other end of the 20m cable with the same 2 cables listed above, still no success (Italics for easier reference in replies).
I know the LaCie Cloudbox can't max out 1Gbps LAN from a single hard drive, just that it negotiates such speed.