That's exactly what hit me: I was trying to federate node to deployment manager when I got this error:
ADMU0036E: The Deployment Manager cannot lookup by name host .. at address 127.0.0.2
I checked local config: no 127.0.0.2 address was there.
I found this thread on developerWorks, and it helped me - I just needed to turn of loopback interface with:
/etc/init.d/network stop lo
After that addNode went smoothly.
Software version: WAS 126.96.36.199, SLES 11.1