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Question for Spidey on Cisco 1912 switch

F

Fatt

Senior member
I would have done this in a PM, but it occurred to me that the answer might be useful for everyone.


I just picked up a Cisco 1912 Switch pretty cheap. It's supposedly the C1912-EN, with 2 100baseTx ports and the Enterprise IOS.

The AUI port is pretty hosed. It's got some rust in it and a couple of pins broken off, although that's not a real big issue for me except for what it implies about what condition the switch is in.
If there's nothing e;se wrong I have a non-working 2501 I can steal an AUI port from and do some old fashioned hardware hacking.

Thing is, I have spent VERY little time playing with switches.

On a router I basically just power it up, stick a console cable in it and do a few show commands to see if I'm good to go.
On a switch, I dunno...

I pluged it in, it boots up and all the green lights come on, but other than plugging two hosts into it and pinging/telneting across the switch, I'm not sure what else to do for function checks.

I was wondering if you had some guidance for me here. Any advice?
 
So you have no console port? If so then just plug into the console port and you'll have command line access to it.

although I think the 1900 series switches are menu based. The AUI port is actually a ethernet port - leave that alone. If you go messing with it you might fry the ethernet controller for the switch and turn it into a paper weight...there's power on some of those pins.
 
Oh...

The pinouts on a 1912 AUI are different from a 2501?

That's too bad. I was hoping I could replace the female plug with a good one I pulled off a dead router.


But yes, I do have a console port.
I'll fire it up first thing in the morning and see how it looks.

Thanks.
 
Originally posted by: Fatt
Oh...

The pinouts on a 1912 AUI are different from a 2501?

That's too bad. I was hoping I could replace the female plug with a good one I pulled off a dead router.


But yes, I do have a console port.
I'll fire it up first thing in the morning and see how it looks.

Thanks.
Click to expand...

AUI is ethernet. Aren't you the guy who want to attach an AUI port to a serial port?

AUI is ethernet.
AUI is ethernet.
AUI is ethernet.
AUI is ethernet.
AUI is ethernet.
AUI is ethernet.
AUI is ethernet.
AUI is ethernet.
AUI is ethernet.
AUI is ethernet.
AUI is ethernet.
AUI is ethernet.
AUI is ethernet.
AUI is ethernet.
AUI is ethernet.

You want a transceiver for it? PM me your address and 10 bucks and I'll send you one.
 
If it's an early 1900, it might be one of the old Kalpana chassis. The menu might not be very Cisco-like.

It's been a long time. I'm actually one of the small crowd that actually got a "CSE" (Certified Switch Engineer) from Kalpana ( I still have my Cert & Lapel Pin 😀 - Nice frame, real spiffy cert ...)

The code may be upgradeable ... within the limits of the flash & RAM.

Good Luck

Scott

(I think you're right Spidey....about wanting to connect Ethernet up to a serial port ... how's that going Mr. Fatt?)

 
Spidey -

Yes, I am the guy who was trying to figure out if there was a way to configure a serial port to act like an ethernet port.
I'm into hardware hacking.

Anyway...
I'm not sure why you felt compelled to repeat "AUI is Ethernet" a dozen or so times.

Obviously you were trying to drive home a point, but I'm not sure what, and I wonder if you got the wrong idea about what I was proposing.

Did you think I was going to try to take a DB-60 serial port out of a broken 2501 and use it to replace a bad AUI port on the 1912?


You do know that a 2501 has an AUI port also, right?
I mean, you have what...? 8 of them?
I would assume you know.


Just for the record....

I was thinking about removing the actual physical female AUI jack on a bad 2501 and using it to replace a bad female AUI jack on a 1912.

And yes, I do know that AUI is Ethernet.

Hence my inquiry as to whether there was any physical difference between the AUI port on a 1912 and the AUI port on a 2501, which would prevent me from transplanting the actual female jack from one into the other.

Oh and, yes, I'd love to buy an AUI transceiver from you fro 10 bucks. How many you got?
 
Originally posted by: ScottMac

(I think you're right Spidey....about wanting to connect Ethernet up to a serial port ... how's that going Mr. Fatt?)
Click to expand...

I haven't been able to gather enough information yet, although it's not exactly on the front burner.

But basically, to do this I'd have to hand wire from each individual pin-out on the DB60 serial port to each individual "pin-in" on the AUI side of a Transceiver.

So I'd need to know ALL the pinouts on both the serial port (while configured as asynch) AND the pinouts on an AUI port.

AND I'd need to figure out how to do this on paper, including the actual router config, before I'd be willing to "waste" a router on the project, even a used one that I'd gotten for $150.
 
So I'd need to know ALL the pinouts on both the serial port (while configured as asynch) AND the pinouts on an AUI port.
Click to expand...

Fatt, please tell me your kidding?

-edit- I searched for some tranceivers and didn't find any. We must have thrown them all away. Sorry bud.:frown:
 
Originally posted by: spidey07
So I'd need to know ALL the pinouts on both the serial port (while configured as asynch) AND the pinouts on an AUI port.
Click to expand...

Fatt, please tell me your kidding?
Click to expand...


Why should I tell you that?

Do you WANT me to lie to you? 😛 😀


Look, Both AUI and DB60 serial are going to have pins for transmit and receive, reference voltage and signalling.
Voltage can be brought down by resistors.
Serial ports can be configured ASYNC in the IOS.

Look, I don't know if this is something that's do-able, and even if it is, I don't know if I can get it working in more than one direction, BUT...
I don't have to violate the laws of physics here.

This is something that COULD be engineered.

Don't forget... The router is already doing this sort of thing internally.

Could I do it EXTERNALLY with just the existing IOS, some wiring diagrams and a soldering iron?

I don't know. This could be well beyond my abilities.
But if I can build a digital timer using a piece of cardboard as my circuit-board and a used polaroid film pack for a power source, I think I can CONSIDER the serial-to-ethernet project without being considered completely crazy.
____________________________________________________
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Sorry to hear about the transceivers. if you find one, let me know.
 
Lets say you did get the voltage and clocking right.

Well layer1 still isn't working. Ethernet is manchester 4b/5b encoded. Meaning 5 bits for every 4 bits of payload. Serial interfaces don't use this encoding, nor is the serial driver on the router capable of doing manchester encoding.

Hope that helps.
 
10base uses manchester

100base uses NRZI and MLT-3.
And RS-232, which is serial, uses NRZI


And yes, I realize that I said that in such a way that the statement itself is incorrect in absolute terms. You don't have to point out why.
I'm not the ignorant noob that I suspect you may be assuming I am, based on my expression of a single crazy idea.


Look, I may find that I cannot do this in an "mechanical" way. If so, so be it.

When I am ready to give up on this notion as being hopelessly beyond my engineering skills, I'll be sure to let you know and admit defeat publically.

In the meantime, it's MY crackpot idea, and I'm free to tilt at this windmill to my heart's content. 😀



And keep an eye out for transceivers....

I'm still assembling my CCNP lab and I have 3 exams to go.
 
A garden hose filled with water carries liquid and is measured in Gallons Per Minute. A hose from a gas pump also carries liquid and measures it's flow in GPM. Doesn't mean that it's good to pump water in your gas tank or gas onto your lawn. You'd get liquid at a certain speed from both, but the results certainly wouldn't be what you intended.

- G
 
I just wanted to add on about why he repeated AUI = Ethernet....it's because many really think it's serial because of cisco's pinout.

As someone who sells Cisco, I cannot tell you how many times I have told a customer they need to buy a transceiver and forget about it. They sometimes think they can forget their NIC and just rig COM1 or COM2 to the router and be done with it. I am not saying it's impossible and I am not saying it is.

Regarding the rusted port, probably was sitting on a pallet in some port for a few months.....we have purchased chassis with mud, dead rodents, and even a bird's nest with eggs from some companies.
 
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