3com 3870 (3CR17451-9) Console Connection (Help me, abrooks3640)

[tbyehl]

thread545-1700212

Hoping to find out if abrooks3640 or anyone else has figured out the RJ-45 console wiring on the 3com 3870. I picked up one on eBay and am having the same issue that abrooks3640 described in his thread -- it doesn't DHCP, the pin-out in 3com's manual gets me nothing, with or with-out a null modem adapter, and the alternate pin-out that abrooks3640 described doesn't seem to send correctly.

 

[tbyehl]

I borrowed a Cisco RJ45->DB9 adapter from work and that did the trick.

 

[troesch]

Ok, I was having this problem too... eventually got frustrated and hacked a cable apart and started crossing wires... I could read the startup, so knew 2 and 5 were right... just needed to figure out where 3 went.

DB9 <-> RJ45
2 <-> 3
3 <-> 6
5 <-> 5

Hope this helps someone!

Ted.