HP Core Switch - Routed VLANs DHCP not working

[Netwacky87]

Hi all,

 

We've got a HP 5412rzl2 core switch and we've turned on IP routing to do some inter-vlan routing. Since then, our VLAN's don't seem to be receiving DHCP leases (Just IPIPA's)

 

I've set up dhcp-helper addresses for the required DHCP server in each VLAN's but that doesn't seem to have made a difference. I've read that it may need a reboot? (odd!)

 

Thanks all!

Edited August 9, 2020 by Netwacky87

[FN-GM]

Did you add the helper on your Layer 3 (the one you enabled IP Routing) switch?

 

I assume your DHCP server also has had the scopes created?

[Netwacky87]

Did you add the helper on your Layer 3 (the one you enabled IP Routing) switch?

 

Yeah, each VLAN on the Layer 3 switch has had IP helpers for each DHCP server in their VLAN.

 

I assume your DHCP server also has had the scopes created?

 

Yeah, these are existing DHCP servers which worked previously.

 

 

Thanks for your help!

[Steve21]

I assume you enabled DHCP-relay on the core too if it's not already enabled too?

 

You got the config of what you got setup available to see? Might be quicker (obviously without any passwords etc )

 

Steve

[Netwacky87]

I assume you enabled DHCP-relay on the core too if it's not already enabled too?

 

Yeah, DHCP-relay is enabled too.

 

 

; J9851A Configuration Editor; Created on release #KB.16.08.0002
; Ver #14:2f.6f.f8.1d.fb.7f.bf.bb.ff.7c.59.fc.7b.ff.ff.fc.ff.ff.3f.ef:40
hostname "B******"
module A type j9538a
module B type j9549a
module C type j9550a
module D type j9550a
module E type j9550a
module F type j9550a
module G type j9550a
module H type j9550a
module I type j9550a
timesync ntp
ip default-gateway 192.168.1.2
ip route 0.0.0.0 0.0.0.0 192.168.1.2
ip routing
interface A1
name "*** Room"
exit
interface A7
name "*** Link"
exit
interface A8
name "*** Link"
exit
interface B21
name "P**"
exit
interface B22
name "P****"
exit
interface B23
name "C**"
exit
interface F17
name "NVR***"
exit
snmp-server community "public" unrestricted
snmp-server location "**** Room"
oobm
ip address dhcp-bootp
exit
vlan 1
name "DEFAULT_VLAN"
no untagged A7,C7,C10,E2,F3,F5,F13,F17-F18,F23-F24,G1,G16
untagged A1-A6,A8,B1-B24,C1-C6,C8-C9,C11-C24,D1-D24,E1,E3-E24,F1-F2,F4,F6-F12,F14-F16,F19-F22,G2-G15,G17-G24,H1-H24,I1-I24
ip address 192.168.1.85 255.255.252.0
ip helper-address 192.168.1.6
ip igmp
exit
vlan 2
name "Staff Wifi"
untagged E2,F3
tagged A1,A5-A6,A8,B21-B23,F11
no ip address
exit
vlan 3
name "Student Wifi"
untagged C10,F5
tagged A1,A5-A6,A8,B21-B23,F11
no ip address
exit
vlan 10
name "S****"
untagged A7
tagged F7
ip address 10.10.0.1 255.255.252.0
ip helper-address 10.10.0.5
ip helper-address 10.10.0.3
exit
vlan 99
name "V*** "
untagged F13
tagged A1
no ip address
exit
vlan 100
name "C****"
untagged G1
tagged A1,A5-A6,A8,B21-B23,F11,F14,G5
ip address dhcp-bootp
ip helper-address 192.168.4.2
exit
vlan 200
name "D***"
untagged G16
tagged A1-A8,B21-B24,F11,G1
no ip address
exit
vlan 254
name "VoIP"
tagged A1,A5-A8,B1,B21-B23,F1,F11,G5
no ip address
exit
vlan 500
name "C***"
untagged C7,F17-F18,F23-F24
tagged A1-A8,B21-B24,F7,F11,G1,G5
no ip address
exit
spanning-tree
no tftp server
no autorun
no dhcp config-file-update
no dhcp image-file-update
device-profile name "default-ap-profile"
cos 0
exit
activate software-update disable
activate provision disable
password manager

 

Thanks all for your help again.

Edited August 9, 2020 by Netwacky87

[FN-GM]

Your IP helper addresses are not consistent. What is the IP of your DHCP server? And What VLANS are having problems with getting DHCP addresses? Edited August 9, 2020 by FN-GM

[Steve21]

Is there a certain VLAN it's a problem with or lots? You seem to have multiple DHCP servers listed?

 

VLAN 1 - ip helper-address 192.168.1.6

VLAN 10 - ip helper-address 10.10.0.5

VLAN 10 - ip helper-address 10.10.0.3

VLAN 100 - ip helper-address 192.168.4.2

 

Which of these 4 are your DHCP servers? As all the VLANs should be pointing to the same helper address

 

Steve

[Netwacky87]

Your IP helper addresses are not consistent. What is the IP of your DHCP server? And What VLANS are having problems with getting DHCP addresses?

 

So we have

 

VLAN1 (default) 192.168.1.6 (Windows DHCP) on 192.168.0.0/22

VLAN2 (guest wifi) 10.16.0.2 (Smoothwall DHCP) on 10.16.0.0/20

VLAN3 (RADIUS) 10.30.0.2 (Smoothwall DHCP) on 10.30.0.0/20

VLAN100 192.168.4.2 (Smoothwall DHCP) on 192.168.4.1/24

 

Thats the main ones

 

I noticed that vlan100 had one of our domain PC's on VLAN1 (default) earlier...

 

Thanks!

[Netwacky87]

Is there a certain VLAN it's a problem with or lots? You seem to have multiple DHCP servers listed?

 

VLAN 1 - ip helper-address 192.168.1.6

VLAN 10 - ip helper-address 10.10.0.5

VLAN 10 - ip helper-address 10.10.0.3

VLAN 100 - ip helper-address 192.168.4.2

 

Which of these 4 are your DHCP servers? As all the VLANs should be pointing to the same helper address

 

Steve

 

I must be misunderstanding what an 'IP HELPER' is...there are multiple DHCP servers, one in each VLAN on different ranges.

[Steve21]

I must be misunderstanding what an 'IP HELPER' is...there are multiple DHCP servers, one in each VLAN on different ranges.

 

Yep Seems so, unless I'm misunderstanding what you're trying to do. If they're on the same VLAN as the DHCP server (if you're using multiple) you shouldn't need to use IP helpers as they broadcast on said VLAN (IP helpers are when it can't get a response on it's own VLAN)

 

As long as each device is configured (server wise) to respond to the correct scopes etc it shouldn't make any difference.

 

So currently, what clients can/can't get an IP address? Are any working via either windows or smoothy?

 

Steve

[Netwacky87]

Yep Seems so, unless I'm misunderstanding what you're trying to do. If they're on the same VLAN as the DHCP server (if you're using multiple) you shouldn't need to use IP helpers as they broadcast on said VLAN (IP helpers are when it can't get a response on it's own VLAN)

 

As long as each device is configured (server wise) to respond to the correct scopes etc it shouldn't make any difference.

 

So currently, what clients can/can't get an IP address? Are any working via either windows or smoothy?

 

Steve

 

Quite new to IP routing, so thank to all for helping!

 

The VLAN500, 2 & 3 can't get DHCP leases (Smoothwall). The VLAN1 (default) can get leases from a Windows DHCP server. Should I remove the helpers from all the VLANs?

[Steve21]

So just to confirm on your smoothwall:

 

You have DHCP server enabled

You have the 3? interfaces you're using ticked

And then 3 profiles setup one for each of those ranges?

 

Then those interface ports are under your list of config above?

 

Steve

[Netwacky87]

So just to confirm on your smoothwall:

 

You have DHCP server enabled

You have the 3? interfaces you're using ticked

And then 3 profiles setup one for each of those ranges?

 

Then those interface ports are under your list of config above?

 

Steve

 

Yeah, all correct. DHCP started to not work properly when IP routing was enabled.

[Steve21]

I'm gonna guess it's the static routes missing, but I don't get why you're enabling routing if you want these VLANs (2,3,100) separate from your main network/DHCP etc Or is it only routing on other VLANs that aren't those 3?

 

Steve

[Netwacky87]

I'm gonna guess it's the static routes missing, but I don't get why you're enabling routing if you want these VLANs (2,3,100) separate from your main network/DHCP etc Or is it only routing on other VLANs that aren't those 3?

 

Steve

 

Or is it only routing on other VLANs that aren't those 3?

 

Yeah, the above. I'm routing between VLAN 1 and VLAN10 (separate site) which seems to be working fine but has messed up the DHCP of the other VLANS (2,3 & 100)