IBM Blade RackSwitch G8124 / G8124R

alijnclarke

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Feb 9, 2017
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Sorry to revive an old thread, but i just got one of these switches and am running into the same problem.. does anyone have a console cable i could buy or a source in the uk?
 

zeropoint46

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Mar 2, 2017
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I stumbled upon this thread looking to possibly replace the fans in the switch cause they are loud :( but doesn't look like anybody here has done that, so I may as well help where I can.

alijnclarke,
I had the same issue as you, when I got the switch there was no cable. All I could finally find online was "field replacement units" for more than $120, which was what I paid for the switch so F that... I ended up building one, it was very easy. I use the following parts:
rj-45 crimper
rj45 ends: RJ-45 MODULAR PLUGS RJ45 - 100 PACK FOR SOLID - Monoprice.com
db-9 rj-45 adapter: DB9F/RJ-45,Modular Adapter - Monoprice.com
mini usb cable: 3ft USB A to mini-B 5pin 28/28AWG Cable - Monoprice.com

get 2 of the rj45 adapters cause you can easily mess one up on the first attempt. the go here to see the pinout diagram (page 25):
https://www-304.ibm.com/support/docview.wss?uid=isg3T7000290&aid=1

it's pretty straight forward once you figure out how they are describing the pinout in 3 different tables. basically in the db adapter you just connect pins 1,4,6 all together, they don't connnect to the usb cable, and connect pins 7, and 8 together, they also don't connect to the usb cable. the rest of the pinout is clearly layed out in the doc. all of this took about 10-15 min.

one thing I did find out though once I had the cable, is if you reset the switch, which you can do from a button on the front. It seems like the mgmt interface come configured with DHCP by default. So you might possibly be able to factory reset the switch and put a dhcp server on your network then get to it via IP and not need the cable at all. That said, it is nice to have the cable.
 
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PnoT

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Mar 1, 2015
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Has anyone figured out how to run "not approved" transceivers in these yet? I know CISCO and a few other switch brands have hidden commands to enable them regardless but I can't find anything with this switch yet. It's pretty picky with transceivers so far and only a few have worked for me but DAC work awesome. Also someone on page 1 mentioned running Juniper FM on these??

I picked up a couple of SuperMicro X10SDV-4C-TLN2F-O that have 10Gbase-T and a Mikrotik 10GB SFP+ -> 10Gbase-T rj45 adapter to try and plug them into the switch and it's not working.

@zeropoint46
Did you switch the fans in yours yet?
 

fohdeesha

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If it is indeed identical to the Juniper EX2500 - I can get Juniper's firmware running on it quite easily, with a similar process to my LB6M > Turboiron and Delta 7024 > Dell 8024 guides. Both the IBM and juniper also come with u-boot from factory (I know juniper does, and I think IBM does from memory), so it should be even easier than those two guides actually.

@PnoT - to figure this out quickly without a few weeks of PM'ing back and forth, remote access to the serial console of the IBM would make it really easy, whether it be a remote SSH connection with screen/minicom to the serial port, or teamviewer on windows or something. If for some reason your IBM gets bricked attempting the flash (slim chance, haven't done it yet) I will ship you my JTAG unit free of charge to recover it.

@PigLover if you still have your actual EX2500, there's a couple commands you could run for me that would also speed up the process. I'll give both you guys top credit at the front of the guide
 

fohdeesha

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So, Juniper was nice enough to even ship their bootloader separately for the EX2500 so I don't even need to extract it from their usual giant tar/gz'd OS image. Looking at the bootloader, It's got the standard "4B FF F0 04" PowerPC boot/address jump instruction at the very end of the bootloader, where it should be: https://i.imgur.com/5ghN5hN.png

So, oversimplifying a bit, junipers bootloader just needs to be copied to IBM flash so that end address instruction ends up at the bottom/end of flash (usually 0xFFFFFFFC )

if I hear back from you guys soon I would imagine I can have a guide for this by monday
 

fohdeesha

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Did some more digging and decompiling of both the juniper and IBM images - they're definitely rebrands of the same design.

ASIC is intel - Intel® Ethernet Switch FM4224 Product Specifications

In fact they're so similar, the underlying linux inittab is near identical in both the juniper and IBM firmware, both launching the same module for the main Fulcrum ASIC interface:

Code:
::once:/bin/agetty -n -l /bin/bladeOSLaunch 9600 ttyS0

both use u-boot as well for booting: Imgur

I'd imagine this would be a 15 minute job to figure out, assuming I have access to a G8124 serial console remotely

edit: seems like it might be a downgrade though, the juniper firmware was last updated in 2010, and seems to be layer 2 only. So maybe only useful if you need an l2 switch and want to get rid of the transceiver restrictions. This could be done the other way round for EX2500 owners too, if they wanted to upgrade to the IBM firmware released this year with full L3
 
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PnoT

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Mar 1, 2015
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I can provide you access to the G8124 if you let me know what you need as I've never connected to the console of it before but I do have have the console cable.

Would it be possible to see if the commands are hidden within the firmware or to add them (complete noob here when it comes to this kinda stuff). Would the Lenovo firmware work or do you think it's an exact copy of IBM?

Thanks for all of your work so far you've been digging around quite a bit for a solution!
 

fohdeesha

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Are you on linux or windows?

if windows, you need a program like putty to connect to the serial console of the switch, then a screen sharing program like teamviewer so I can access it

if linux, something like screen or minicom to connect to the serial console, then temporary ssh access so I can access it

I had a look through the image and didn't find any hidden commands to unlock transceiver support. Definitely can't add them, that would involve completely decompiling the PPC assembly, adding it, then compiling it back into something that works, which would probably be a few thousand man hours
 

PnoT

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I have windows and can setup the console cable this afternoon. Shoot me a PM when a good time frame for you might be to get things going.
 

sthen

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Oct 11, 2018
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Unsure about G8124, but G8124E with current firmware has a hidden command (it doesn't tab-complete, needs typing in full), "system unsupported-transceiver" (though with no DOM support). If that doesn't work it's probably easier to get vendor-coded transceivers. flexoptix have ones which work (1Gb totally OK including DOM, 10Gb work but don't show DOM). FS.com also have optics that should work but I haven't tested them and don't know whether they have working DOM or not.
 

PnoT

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Mar 1, 2015
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Unsure about G8124, but G8124E with current firmware has a hidden command (it doesn't tab-complete, needs typing in full), "system unsupported-transceiver" (though with no DOM support). If that doesn't work it's probably easier to get vendor-coded transceivers. flexoptix have ones which work (1Gb totally OK including DOM, 10Gb work but don't show DOM). FS.com also have optics that should work but I haven't tested them and don't know whether they have working DOM or not.
I've tried the command from the default prompt, after enabled, in config, and at the system and nothing works. Am I doing something wrong?

I wonder if the 8124E firmware can be applied to this switch? Thanks for bringing to light a hidden command at least.