we have an HPE 1920 PoE switch connected to a Cisco 1841 router, vers 12.4. The HP switch has two VLANs:

  • Data - VLAN 1 -
  • Voice - VLAN 55 -

The port on the switch that uplinks to the router has VLAN 1 untagged and VLAN 55 tagged.

The router has two subinterfaces configured:

interface FastEthernet0/1.1
 encapsulation dot1Q 1 native
 ip address
 no snmp trap link-status
 no cdp enable
interface FastEthernet0/1.55
 encapsulation dot1Q 55
 ip address
 no snmp trap link-status
 no cdp enable

show vlans on the router shows No Virtual LANs configured.

There is connectivity on the default VLAN okay but not for the second VLAN, I'm not even able to ping the .55 subinterface from the switch.

Is there a way to get this working please?

  • what does a "show vlan" on the Cisco router tell? (you can edit your question to add the info). also please add the router model and IOS version.
    – JFL
    Commented Jan 11, 2017 at 13:22
  • Hi, thanks for the reply. There are no vlans on the router, I read somewhere that it uses subinterfaces rather than vlans as it is a routed port rather than a switched port..?! But that may be just my inexperience or misunderstanding...
    – Adam D
    Commented Jan 11, 2017 at 13:30
  • Where you defined VLANS? on switch or on router? Commented Jan 11, 2017 at 13:32
  • vlans on the switch and matching subinterfaces using dot1q encapsulation on the router
    – Adam D
    Commented Jan 11, 2017 at 13:34

2 Answers 2


Check your switch configuration. You have to define the trk port for that VLAN to go outside. Example:

trunk 49-50 trk1

vlan [vlan_id] 
name "valn name"
untagged [port number that you want to untagged]
tagged Trk1
no ip address
  • do you need a trunk port? Isn't that just a group of ports acting as one in HP terminology, similar to a port-channel in Cisco
    – Adam D
    Commented Jan 11, 2017 at 13:38
  • U need to tell VLAN from where you want to go out. Commented Jan 11, 2017 at 14:09
  • the port that uplinks to the router is already tagged in the vlan: vlan 1 untagged 1-24 vlan 55 tagged 1-24 is that not the same thing?
    – Adam D
    Commented Jan 11, 2017 at 14:37

Thanks everyone but I found out what the issue was, the uplink port on the switch was enabled for Voice VLAN, as soon as I disabled this, it worked as expected.

  • You should accept your answer to that the question doesn' keep popping up forever, looking for an answer.
    – Ron Maupin
    Commented Feb 10, 2017 at 19:46
  • Sorry bud, I'm not sure what you mean?!
    – Adam D
    Commented Feb 10, 2017 at 23:41
  • You accept answers that answer your question. This keeps the question in the site, but questions with no accepted answers periodically pop to the top of the questions list, looking for an answer. There should be large checks on the left side of the answers. You can check that on an answer that you accept, but only one answer can be accepted. See the tour.
    – Ron Maupin
    Commented Feb 10, 2017 at 23:45

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