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2960 Switch is blocking that connection


Have a new UPS connected to the switch and trying to register the UPS to the cloud, but something in the switch is blocking that connection. Can ping the switch and see the switch, but can't make this connection.


interface GigabitEthernet3/0/17
switchport access vlan 532
switchport mode access
switchport voice vlan 11
mls qos trust dscp
spanning-tree portfast
spanning-tree bpduguard enable


The UPS is getting an IP Address and  i can ping the UPS on the Network.

Any idels what i am missing

6 Replies 6

Jaderson Pessoa
Existe algum dispositvo que gere bpdu neste UPS?

Try disable it spanning-tree bpduguard enable and check if connections still working.
Jaderson Pessoa
*** Rate All Helpful Responses ***

disable it spanning-tree bpduguard enable did not work


Alex Pfeil
Rising star
Rising star

show mac address-table int gi3/0/17

Copy the MAC address.

On router, show ip arp | i MAC address

If you see the MAC on the switch and the IP address in the arp table, it is not the switch.

MPC-VV-N3K_Core1# show ip arp

Flags: * - Adjacencies learnt on non-active FHRP router
+ - Adjacencies synced via CFSoE
# - Adjacencies Throttled for Glean
D - Static Adjacencies attached to down interface

IP ARP Table
Total number of entries: 1
Address Age MAC Address Interface 00:02:33 2829.8615.22c3 Vlan532

paul driver
VIP Expert VIP Expert
VIP Expert


First of all can the cloud be reached from the switch/router supporting vlan 532 and more importantly can it be reached from that vlan 532 L3 interface, Also what port is this ups trying to connect too and is it possible that is being restricted?

Try telneting to the cloud destination/port from the L3 switch/router sourced from vlan 532 for verification

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Kind Regards

To build on the excellent point that Paul made I would ask:

1) is there routing in place that would forward traffic from vlan 532 to the Internet?

2) is there address translation in place that would translate the private address used in vlan 532 to a public IP for accessing the Internet?

3) is there any ACL or other security policy that might block traffic from the UPS to the cloud?






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