The Dell switch we SNMP walked does not appear to provide connectivity information using any of the MIBs used by NTM. Here is what NTM uses, which is fairly generic and supported by most:
BRIDGE-MIB
==========
1.3.6.1.2.1.17.4.3.1
Q-BRIDGE-MIB
============
1.3.6.1.2.1.17.7.1.2.2.1
LLDP-MIB
=========
lldpConfigManAddrTable (1.0.8802.1.1.2.1.1.7)
lldpRemManAddrTable (1.0.8802.1.1.2.1.4.2)
Looking at the results of the walk, we get nothing for LLDP-MIB or Bridge-MIB and only get the 2nd and 3rd columns from the Q-Bridge-MIB table. The first column containing the MAC addresses and the second contain the ports.
As the switch is not providing any connectivity information, NTM is not able to establish what is connected to the switch and on what port.
Any idea on how to fix this for any of you that have Dell Force10 switches with NTM?