ArubaOS and Controllers

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Contributor I

Outgrowing built-in DHCP, need help.

Well, the time finally came when we need to give out more than 512 addresses (which we hear is the recommended limit for the Aruba DHCP daemon... =( So now we need to figure out how to securely and best configure an external DHCP box for doing this.

Anyone available to help walk me through this...
1) We currently have a private vlan (1) that is on the 10.10.9.x network with a controller IP of 10.10.9.10. All internal (staff) traffic goes to this vlan, hits our internal MS dhcp server and grabs a 10.10.9.x address.

2) Guest wifi has been using vlan (100) which is setup as 192.168.100.x (with) .1 as the IP address. (subnet mask has been 255.255.255.248, so we really had 1024 addresses ranged) and has been grabbing addresses from the built in Aruba DHCP server (in DHCP as the 192.168.100.0 network with 192.168.100.1 as the default router.)

3) We'd like to setup a new DHCP server to handle 192.168.0.x traffic, but we need to know how to configure Aruba to look outside for those IPs.

Right now, vlan 1 has all of the ports (the 4 gb nics) associated with that vlan, but I'm not sure if that matters at all.

What needs to be to setup a new vlan (say 192 for example) that will route out of the Aruba and find the appropriate dhcp server?

Thanks for the help. I assume this is simple and I'm just missing the obvious.
Scott Miller
Guru Elite

Re: Outgrowing built-in DHCP, need help.

1. Configure an external DHCP server to give out addresses in that range
2. Configure the Aruba controller, on the VLAN interface with a helper address pointing to that DHCP server:

config t
interface vlan 100
ip helper-address


Colin Joseph
Aruba Customer Engineering

Looking for an Answer? Search the Community Knowledge Base Here: Community Knowledge Base

Contributor I

Re: Outgrowing built-in DHCP, need help.

Edit your 192.168.100.1 IP address and add the IP address for your external DHCP server in the DHCP Helper Addresses field.
Contributor I

Re: Outgrowing built-in DHCP, need help.

I created a new VLAN instead for testing (before bringing the production one down), but it shows to be in an operation state of "down". Any ideas?
Scott Miller
Guru Elite

Re: Outgrowing built-in DHCP, need help.




A VLAN that is not assigned to an interface, which has no users in it, will be considered "Down".

turn it up manually by doing this

config t
interface vlan x
operstate up

It will automatically turn UP if users are placed into it without doing this.



Colin Joseph
Aruba Customer Engineering

Looking for an Answer? Search the Community Knowledge Base Here: Community Knowledge Base

Contributor I

Re: Outgrowing built-in DHCP, need help.

Ok. Ran the operstate command which brought the vlan up, and I have a virtual AP assigned to that vlan, but when I enable the virtual AP it never comes up as an available AP. If I switch back to the old VLAN 100, the virtual AP shows up right away. Weird.
Scott Miller
Guru Elite

Re: Outgrowing built-in DHCP, need help.

type "show profile-errors" to see if there is anything ELSE wrong with that WLAN.


Colin Joseph
Aruba Customer Engineering

Looking for an Answer? Search the Community Knowledge Base Here: Community Knowledge Base

Contributor I

Re: Outgrowing built-in DHCP, need help.

Ran "show profile-errors" and it responded with this...
Invalid Profiles
----------------
Profile Error
------- -----
wlan virtual-ap "arubatest" VLAN 192 does not exist
aaa authentication via auth-profile "default"

So, not sure what this means. The VLAN exists, and shows an op status of UP.
Scott Miller
Guru Elite

Re: Outgrowing built-in DHCP, need help.

type "show vlan status" to see if it truly exists

if ti does not, type this:

config t
vlan 192


Colin Joseph
Aruba Customer Engineering

Looking for an Answer? Search the Community Knowledge Base Here: Community Knowledge Base

Aruba Employee

Re: Outgrowing built-in DHCP, need help.

Solution below (I worked with the customer today)

conf t
wlan virtual-ap arubatest
no vlan
end
write memory
conf t
interface vlan 192
shutdown
no ip address
no ip helper-address
exit
no vlan 192
exit
write memory
conf t
vlan 192
interface vlan 192
ip address
ip helper-address
no shut
exit
write memory

then check "show vlan" and show ip interface brief"
make sure vlan is there and interface is UP.

conf t
wlan virtual-ap arubatest
vlan 192
end
write memory

show ap essid
show profile-error

This should fix the issue
MKS
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