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HP 1910 no DHCP on Vlan

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Nieks

Technical User
May 16, 2011
5
NL
I have a question about problems with dhcp on a Vlan on a HP 1910-8
I have attached the switch on a interface on my firewall. At the firewall interface is a vlan configured with vlan id 3.
On the vlan interface i have enabled a dhcp server.
When i configure a pc with vlan id 3 i get an ip from the dhcp server (firewall vlan interface). The pc is attached to the vlan interface on the firewall.
When i attach the HP 1910 with a tagged vlan id 3 on the vlan interface on the firewall i get no ip from the dhcp.
Even untagging does not solve the problem

Firewall interface ip: 172.16.0.1
Vlan ip: 172.17.0.1
Vlan id: 3

Management ip HP 1910: 172.16.0.2
Vlan's: 1,3
Vlan1: untagged
Vlan3: tagged

Do i need to configure anything else?
 
So the router interface is a layer3 interface with 172.16.0.1 in the default VLAN 1 untagged with a subinterface with 172.17.0.1 tagged in VLAN 3?

Therefore the HP switchport that is patched to the router should have VLAN1 untagged and VLAN3 tagged.

And any PC connected to this switch should not have any VLAN configured on it, and its switchport should be configured as untagged in whichever VLAN you want the PC to be on.
 
Yes, it is a layer3 interace configured with the default vlan1 untagged and a tagged vlan3.
On the switch i have Vlan1 untagged en Vlan3 tagged. I will connect some accesspoints to the switch with a private (vlan1) and a public (vlan3) wireless network. This did not work so i connected a pc to the switch, this pc also dit not get a ip address from the dhcp.
 
So your PC is patched to a VLAN3 untagged port on the switch?
Manually configure a VLAN3 subnet IP address on the PC and check it can ping its default gateway.
 
Already tried that, cannot ping the gateway
 
Good, so you don't have to worry about DHCP not working, you have to correct a basic switchport misoncfiguration. (Assuming the Router is configured to respond to ping.)

Go over it again -
On the Router, you have VLAN1 UNTAGGED and VLAN3 TAGGED (?)
On the connecting switchport, you have the same (?)
[Test: give the switch an address in VLAN1, configure VLAN1 as the management VLAN - can you ping the router?]
[Test: Repeat with VLAN3]

Configure and access port for VLAN1 UNTAGGED. Put a PC with a VLAN1 subnet address on it on that port and ping the router.
Repeat for VLAN3.
 
From within the switch can you ping both .1 addresses?

From my experience HP prefers all VLANS to be tagged on the trunk
Trying tagging Vlan1 and 3 instead and put the VLAN1 gateway address in the switch
ip default-gateway 172.16.0.1

Marv ccna
 
BOth Tagged or one Tagged and one Untagged is the same thing - as long as both sides are configured the same, it will work.
I've worked extensively in mixed Cisco/Procurve networks, and I don't know what you mean about HP liking all VLANs tagged. The only difference is that Cisco always has an untagged VLAN but HP doesn't have to have one.
 
I just finished a retrofit of an R&D lab that was running HP Procurves off a 6509 Router configured with 400+ Vlans. All vlans that were used on a switch had to be tagged at the both ends of the trunk including the management. If you didn't tag the management you couldn't reach the router interfaces.

Anyway for what it's worth that was my experience with HP.

Marv ccna
 
With Cisco switches, you have to have one VLAN untagged ("Native") on each trunk.
(It's best to create a VLAN for that purpose, eg VLAN99, and use that VLAN for nothing else.)

With Procurve switches, when you create a trunk (multiple VLANs on a link), you don't have to have any of those VLANs untagged - they can all be tagged. I much prefer this.

When you say your VLAN didn't connect unless you made it Tagged (at the Procurve end, presumably), this would indicate you had it Tagged at the Router end.

To configure a VLAN to be Untagged on the Cisco, you need,
#interface FastEthernet0/1.1
Hostname(config-if)#encapsulation dot1Q 1 native
..........................................^^^^^^

native = untagged = switchport mode access/switchport access VLAN 123

I don't think there's any good reason to actually want to use Untagged VLANs on trunks, though.

As I said before, to get it to work, you just have to make sure both ends match, and the different terminology used by different vendors is what catches people out.
 
Thank you for your response. The problem is solved! For whatever reason there was a routing rule enbaled.
I haves send a log file to HP, HP pointed me to the routing rule. Deleting this rule solved the problem.

Thank you
 
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