Showing results for 
Search instead for 
Did you mean: 
Adam Hudson

Cisco 3750 and HP 1810-8G trunking

I'm trying to get a trunk working between my 3760 switch and an HP 1810-8G switch. I understand after reading the posts below that "trunking" for HP is akin to an etherchannel on the Cisco side of things, I don't want that. I want a link that carries multiple VLANs on it.

In the pictures attached I've tagged the ports for the VLANs I want them in (40,70,100) with 100 being my management VLAN. The HP VLAN carrying port should be port 1.

For the port on the cisco switch it's plugged into, here's my config:

interface GigabitEthernetx/x/x
 switchport trunk encapsulation dot1q
 switchport trunk allowed vlan 40,70,100
 switchport mode trunk
 switchport nonegotiate

I doesn't matter whether or not I have the "switchport nonegotiate" in there or not, it still doesn't work.

Also attached is my "Setup Network" page. I have my switch IP and gateway in the management gateway because that's how my other switches are setup.

My problem:The HP switch and anything attached can't get to the rest of the network. I can't ping the HP switch or even anything statically assigned an IP and attached to the HP switch.

The port it's plugged into is showing Up and Up for status.

Any help is appreciated.





Accepted Solutions

Look at your vlan40.jpg.

You just need to change the "T" to a "U" for the ports you want in vlan 40 and then any ports you don't want in vlan 40 you mark as "E".

That is as far as I can tell from the documentation.


View solution in original post


1. I think you are referring to a 3750 switch, not a 3760 

2. Trunking and etherchannel are two different things (the HP documentation is misleading)
    -A trunk is a link 
that forwards vlan traffic between connected switches.
    -An etherchannel is used to combine two or more physical links into one logical link, for increased bandwidth.

3. Your config on the cisco switch looks ok. Just configure the port on the hp switch that is connected to GigabitEthernetx/x/x on the cisco switch as the trunk and the other ports should just be access ports in their assigned vlans. page 43



Daniel, I had to put down this project for a few weeks but I'm picking it back up. I'm still not able to get this switch to trunk correctly. Are there any "gotchas" you've seen when working with this switch?

I've tried two different switches so far, set up the exact same way because I thought maybe something was wrong with the first. That was not the case.


I don't have any experience with the HP switches but had a read of the doc Daniel linked to.

The only thing I noticed is that for vlans 40, 70 and 100 any ports on the HP switch that you haven't excluded you have marked as tagged.

But if you are connecting clients to this switch you don't want the ports tagged you simply want them in that vlan.

The only port that needs to be marked as tagged is the port connecting to the 3750 switch.

Of course I could well be wrong and I am assuming you are using the other ports for clients so please ignore if I have assumed incorrectly.

One other thing, what does a "sh int trunk" show on the 3750 ?


Jon, everything looks good switch side on the trunk port:

Port        Mode             Encapsulation  Status        Native vlan
GiX/X/X    on               802.1q         trunking      1

Port        Vlans allowed on trunk
GiX/X/X    40,70,100

Port        Vlans allowed and active in management domain
GiX/X/X   40,70,100

Port        Vlans in spanning tree forwarding state and not pruned
GiX/X/X    40,70,100


Can you just try this -

1) on the HP change the management port to be the port connecting the 3750

2) on the 3750 add this to the trunk port configuration -

"switchport trunk native vlan 100"

and then see if you can ping the switch itself.


Making these changes I can ping the HP switch's IP from my Cisco switch. I still cannot get anything plugged into the rest of the ports to either pull IP addresses via DHCP or connect to the rest of the network if I manually assign an address to the interface.

Okay did you see may previous post about how you have configured the ports.

Basically the only port that needs tagging on the HP is the one connecting to the 3750.

Any other ports in any of the vlans should be marked as untagged but looking at your attachments you have configured them as tagged.

Which means they will be expecting traffic to be tagged from any connected device and they will be sending tagged traffic to the connected devices.

Unless you are setting up the client to use tagging then you need to mark all ports except the connection to the 3750 as untagged.


Jon, how would I designate specifc ports for specific VLANs then?

Look at your vlan40.jpg.

You just need to change the "T" to a "U" for the ports you want in vlan 40 and then any ports you don't want in vlan 40 you mark as "E".

That is as far as I can tell from the documentation.


Jon, here's what I have now.

VLAN #14070100    
Port 1 settingUEEE    
Port 2 settingEUEE    
Port 3 settingEUEE    
Port 4 settingEUEE    
Port 5 settingEEUE    
Port 6 settingEEUE    
Port 7 settingEEUE    
Port 8 settingTTTU    


So port 8 connects to the 3750 ?

If so that looks good to me as far as I can tell.

Are you saying it still doesn't work ?


Port 8 is connected to the Cisco switch, it still does not work.

It's still however not working. Is it that the management port can't also be the (cisco term) "trunk" port?

Assuming port 8 is connected the 3750.

Are you trying with DHCP or static IPs ?

Are the ports up/up.

It may be STP related ie. don't  know what the equivalent of portfast is so it may take some seconds for the port to come up.