Jump to content
Sign in to follow this  
ArmorAlley

10baseT Hub

Recommended Posts

Hi all,

 

 I have a 10baseT hub that I think may be broken. It still lights up. It just doesn't seem to want to negotiate.

I tested it last night with my B&W G3 running Mac OS 9.2.2. I was able to connect to the Internet on a gigabit hub but not on the 10baseT hub when I switched the ethernet cables for the internet and B&W G3 over to it.

 A thought came to mind on my way into work this morning, could it be the cables? All of the cables are reasonably modern (cat 5 or cat 6). Could these be incompatible with the 25 year old 10baseT hub?

 

aa

Share this post


Link to post
Share on other sites

If the same cables worked with the 1 Gb hub, then it is unlikely it is the cables, unless by making the change to the other hub you corrected a broken wire.  Ports do go bad on hubs and switches.  Did you try other ports on the 10 Mb hub?  It is also possible that due to the age of the 10 Mb hub, some capacitors have failed in the power supply.  I had this happen for some more recent 1 Gb switches I have.

Share this post


Link to post
Share on other sites

I shall try other combinations of ports on the old hub tonight. I'm not really sure what the exact difference is between cat 3, cat 5 and cat 6 cabling. I'll have to spend some time with an explanation of ethernet and a cup of hot cocoa...

 

Share this post


Link to post
Share on other sites

The CAT ratings show what data rates the cables will support and what the longest distance for those rates.  Wikipedia has some good information.

Share this post


Link to post
Share on other sites

That hub may not support auto-negotiation and the Mac (and/or your modem/router) may not know what to do with it. Try configuring the Mac's networking by manually selecting 10b and half-duplex if it's an option. If that doesn't work, maybe try using it with an older Mac that supports only 10b. 

 

Hubs are really cheap and may confuse newer equipment like wifi routers that don't expect to have to interface with antiques. I generally reserve hubs for networks of exclusively vintage equipment (read: 1997 or earlier) for that full nostalgic feel of LAN parties back in the day.

Share this post


Link to post
Share on other sites

Franklinstein ohayou gozaimasu

 

Thanks for the reply. The 10baseT hub is to allow the P475 and SE to connect to the LAN. It is connected to the gigabit hub. I'm fairly sure that the hub does not support auto-negotiation. I assume that these settings are in the Network control panel. The P475 is running Mac OS 8.1 at the moment.

I did learn yesterday that I need to use a crossover cable to connect a hub and a switch together and that cat. 3 cable upwards should be OK for the 10baseT hub.

Share this post


Link to post
Share on other sites
58 minutes ago, ArmorAlley said:

I assume that these settings are in the Network control panel. The P475 is running Mac OS 8.1 at the moment.

I did learn yesterday that I need to use a crossover cable to connect a hub and a switch together and that cat. 3 cable upwards should be OK for the 10baseT hub.

Yeah if they're available these settings are in the Network control panel somewhere. I haven't played with stuff like that in a while so I don't remember for sure.

 

Some networking tidbits:

The CAT rating of a cable refers to the maximum speed the cable can support. CAT1 and CAT2 are old and typically only used for phones, CAT3 is for phones and up to 10bT Ethernet, CAT4 wasn't much of a thing but could support a maximum of 100bT, CAT5 is ubiquitous for 100bT, CAT5e/CAT6/CAT7 all support 1000bT, though depending on the length of the cable run you'll want to use CAT6 or 7 over 5e. The primary differences between the CATs are the grade of the wires used therein and the degree to which the individual pairs are twisted and separated from the others: the tighter the twist and the wider the separation between pairs, the lower the interference, and the greater the possible maximum speed. As such, you can always use a newer cable on an older device with no problems. I've done installs for phones using CAT6 cable.

 

There are two standards for wiring RJ45 cables for networking: TIA-568A and B. For premise wiring, the A standard is primarily used in Europe while the B standard is used in the USA; other regions will vary. The only difference is the switching of the orange and green (send/receive) cable pairs between the two (so the first two pins on A are white-green/green while B is white-orange/orange), A normal straight-through networking cable will be the same standard on both sides (A to A or B to B ). A crossover cable has a different standard on the other side, so it's A to B. This double standard cable switches the send and receive pairs so that they are in the correct position for connecting like-to-like devices (DTE to DTE, DCE to DCE).

 

There are DCE (Data Communication Equipment) and DTE (Data Terminal Equipment) devices. Switches and hubs are DCEs while computers and usually routers (at least, large network routers) are considered DTEs. When you connect like-for-like devices, you need to use a crossover cable because otherwise the devices will be unable to communicate since they would be trying to send or receive data on the same pins. Nowadays the use of a crossover cable isn't strictly necessary, but with older equipment you have to keep in mind that auto-crossover LAN jacks were only recently (2002ish) introduced and weren't really widespread until fairly recently. Sometimes older network devices have a configuration switch and/or dedicated uplink port that will allow you to use a straight-through cable in place of a crossover.

Share this post


Link to post
Share on other sites

Hi Franklinstein

 

I swapped the cables in the ports in the 10baseT hub and it worked (on both the P475, B&W and between the two)! I then other port combos and they worked too. The only difference between the time before posting and now is the crossover cable between the hub and the switch. Before it had been an ordinary ethernet cable.

 

I was a junior sysadmin some 20 years' ago in charge of the tape backups. The cables connecting the patch panels were not crossover cables but they all had uplink ports.

 

Thanks again for your long post. It is most informative.

aa

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

×