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Level 7

ports on one switch not found

A simple network - 7 switches, 347 ports, single subnet (for now), all ports on the default VLAN.  One of the seern switch has this issue after Port Discovery - On the Device Tracker Home page, in "Top 10 Nodes by Percent Used" the top switch is in yellow rather than green; and, I cannot search for an IP address of any host I know is plugged into that switch.  It's a 3com 4500G.  It's the backbone switch; meaning, it has plugged into it servers, other switches, routers, etc.  Anyone with advice on how I figure out shat's happening?  Thanks. 

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OK, 'll have to reply myself.  That yellow band is a Warning - getting low on empty ports on this switch.  And the not able to search on IP address has to do with polling intervals, but I'm still trying to understand that part of the answer and work through the resolution

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Hi McMurphy,

It sounds like there are no UDT Layer3 jobs being created.  Can you check the UDT Job Status page (Settings > UDT Settings) and see whether there are any 'Layer3' jobs listed?

When you performed the 'Port Discovery' in UDT, was the 'Include Router Discovery' check-box ticked?

If the answer is 'yes'; then did you notice whether in the discovery status window whether any routers had actually been discovered?

Finally, does this 3Com backbone device have both Layer2 and Layer3 capabilities (and therefore is it where you would be expecting your IP information to come from?)



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This 4500G is Layer2 and Layer3.  It's my backbone, meaning what's plugged into its ports are: the Windows servers, the other on-site switches (mostly Layer2, with workstations plugged in), and the routers (routers to other sites via T1's; routers to leased lines; firewall; VPN devices); so obviously this is the really busy switch

I've not been noticing the 'Include Router Discovery' before, but I just re-ran port discovery, 'Include Router Discovery' was checked when the page came up, and I left it checked.

In the UDT Job Status page this switch does have a 'Layer 3' job as well as a 'Polling' job.  Other switches are Layer2 only, they have only a 'Polling' job.

Those other switches, not as busy, have a more comprehensive set of hostnames / IP addresseses filled in.  So if I understand this, Discovery goes out and gets the MAC address at each port (except that backbone switch, which has many MAC addresses associated with a port that has another switch plugged in).  Then the polling gets the hostname and IP addresses?  So far our switches are plug in and go - the default VLAN, flat 10.1/16 network (except the DMZ and EXT segments, I haven't started with them yet).  But I've got to get us ready to route to the branches (we still bridge, and multiplex voice/data); segment the servers; get ready for voice over IP.  Getting UDT doing what I need, and understanding what it's doing, will help.


Mike Murphy 

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