[c-nsp] disable NEXT(Near end crosstalk) cancellation on 1000BASE-T port in Catalyst or Nexus brand switch

[Martin T]

Hi,

according to Cisco documentation(for example
http://www.cisco.com/c/en/us/td/docs/routers/access/interfaces/nm/hardware/installation/guide/conntge.pdf)
1000BASE-T ports can not be looped back through use of an external
loopback cable. This should be because of NEXT cancellation
implemented in 1000BASE-T phy. Is there a way to disable this on newer
Catalyst or Nexus brand switches so that one could use RJ45 loopback
cable on 1000BASE-T ports?


thanks,
Martin