After upgrading from LMS 2.51 to 2.6, the majority of our branch network shows as unconnected in Topology Services.
The sites showing as unconnected have been set as seed devices, and can see our service providers on-site routers, via CDP.
The switches used to show as connected to an un-managed device
It was all working prior to the upgrade. Sites that have two switches can still be seen, but the edge device cannot.
I just try summarise what Joe and Michel said before and try to bring light to the terms and dependencies:
LMS process that needs a minimum of one start device (seed) and the snmp RO communities;
it tries to access a device via snmp;
it roams around in your networks gathering device information of all devices it can find through CDP
it DOES NOT DRAW your topology!!
DCR - Device Credential Repository
if a device is discovered by campus AND SNMP reachable it will be automatically added to DCR
LMS process that collects detailed Device Information with SNMP;
ONLY with THIS information ANI server can map your network and you will see devices in your topology (e.g 'Layer 2 view', or 'unconnected devices')
to add interconnection between devices in topology; BOTH sides of a link must be verified by the process ( both devices must be snmp RO accessable for the process )
Both, discovery and data collection are scheduled by default;
1) Verify the devices in question are listed in the DISCOVERY report:
Campus > Reports > Discovery Reports
=> Your device must be listed here, with status REACHABLE!
if it is not in this list, Campus cannot detect it with CDP
try to bypass this issue by adding it as a seed device
=> now, at least, it must appear in the 'Discovery Report'
->if it is listed, check reachability;
->if it is not listed, check Discovery filters ( and/or enable debug);
Reachability (if a device is discovered AND reachable it will be automatically added to DCR)
->if it is reachable, goto 2)
->it it is unreachable, check SNMP communication from *LMS SERVER* to device (keep in mind wrong credentials and access-lists; and/or debugging deiscovery)
2) Verify if these devices are listed in the DATA COLLECTION report:
Campus > Reports > Data Collection Metrics
in the report that opens, click on the number listed in the column 'Total Devices' of the latest report
=> your device must be in this list
->if it is in the list, it should be in any view of Topology Services (e.g. layer 2 view; unconnected devices,..)
->if it is not in the list, check 'data collection filters'
if the filters does not drop the device
enable debugging as Joe mentioned
If devices are shown as 'unconnected' in the Topology, it is mostly, that campus is unable to access one side of the link;
what is about name resolution for the devices and the preferred management IP LMS has choosen for the device on both sides of the link ??
=> open the map, right click on the device and check the management IP!
I hope with this guide you can find the point you have to put the focus on...
(and I hope that I didn?t made a mistake...)