Hi,
I have an issue where NTM shows multiple VLANs on backbones. This is however not always correct, and I cannot use this information determine if the topology is correct.
For example,
The router (RTR) has VLANs 1, 8, 200 and 240 on port 5, but only 1, 8, and 200 on port 1.
Switch A-13 has VLANs 1, 8, and 200 on port 48.
Switch A-11 has VLANs 1, 8, 200 and 240 on port 50.
NTM shows VLANs 1, 8, 200 on the link between RTR and A-11
NTM shows VLANs 1, 8, 200, 240 on the link between RTR and A-13.
Both topology mappings are incorrect, as VLAN 240 cannot travel on either backbone as the devices on both end are not configured identically for VLAN 240.
If I were to use this accurate, I would be incorrect to assume I could place a VLAN 240 device on A13 and it would be seen. Manual intervention is required to confirm VLAN 240 is missing on A-13 port 48.
Showing VLANs on both ends, and not just on the nearest device to the poller is needed, or at least, highlight a VLAN that does not pass-through in a different colour to identify it as present on one end and not both.
My 2 poor coops are now going though 150+ sites to manually verify all the topology links between all switches.
Christian Goulard
Network Engineer
Dufferin-Peel Catholic District School Board
