02-06-2014 08:19 PM
Having a heck of a time trying to get DHCP servers setup on my 620 with ArubaOS 220.127.116.11.
Issue: I'm getting the following error after hitting Apply after adding a DHCP pool:
Error processing command:ip dhcp pool "Employee_DHCP" network 10.1.100.0 255.255.255.0 >> Failed to add pool Employee_DHCP which has 253 addresses. Maximum addresses configurable is 256. Currently configured are 253 addresses. You may want to exclude unused address ranges.
Here are the screenshots. Any help would be appreciated!
Reference: My VLANs:
Here is the DHCP pool I tried to create against the Employee VLAN, VLAN 20 (10.1.100.254):
Here it is added, after hitting "Done":
Now I hit "Apply" and I get the error and the Employee DHCP pool is removed:
Solved! Go to Solution.
02-07-2014 01:11 AM
This is because you already have a DHCP pool configured which contains 253 IP addresses.
You cannot have more than 256 in total.
ACDX #98 | ACMP | ACCP
02-07-2014 09:31 AM
Thanks! So this isn't all that clear in the window - is the maximum a total of 255 *potential* addresses or *actual* addresses?
I ask because let's say I have the two VLANs, both are 255.255.255.0, but even if I try to exclude the ranges to make 255 total, it still fails. Sounds like I need two subnets to *equal* 255, for example:
Employee_DHCP: 255.255.255.224 (30 potential hosts) - 10.1.100.1 to 10.1.100.30 (30 actual hosts)
Guest_DHCP: 255.255.255.128 (126 potential hosts) - 10.1.200.1 to 10.1.200.126 (126 actual hosts)
OR (what I wanted to do):
Employee_DCHP: 255.255.255.0 (255 potential hosts) - excluding 10.1.100.51 to 10.1.100.254 (50 actual hosts)
Guest_DHCP: 255.255.255.0 (255 potential hosts) - excluding 10.1.200.201 to 10.1.200.254 (200 actual hosts)
02-07-2014 12:07 PM
These limitations to the internal DHCP server have been added in ArubaOS 6.3 (and they kinda suck). The limit is based on the number of potential addresses. If you create exclusions in your subnet this will lower this number.
Adding two /24's on a Aruba 620 (= max 256 potential addresses) can be a bit problematic, but it can be done:
1) Add first /24 DHCP scope
2) Exclude *all* addresses in this /24
3) Add second /24 DHCP scope
4) Now adjust the exlusions for both /24's - keeping in mind the total number cannot be more than 256
ACMX#255 | ACMP | ACCP | AWMP
02-07-2014 01:59 PM
So I think I figured it out, but I think there is a bug in the GUI. I bet doing all this in the CLI works since others were able to do this in the CLI (see: http://tnotez.wordpress.com/2013/08/23/day-out-wit
Solution: Create the excluded ranges before adding the new DHCP pool
So you canspan VLANs, but as long as the total is below 255, this workaround works above.
So add the excluded range for the yet-to-be created DHCP Pool FIRST.
Success! I was bit under, did 249 IPs just to make sure.
If anyone from Aruba is watching, this probably warrants a defect report.
02-08-2014 06:30 PM
For the record, I ended up downgrading from AOS 18.104.22.168 to 22.214.171.124 due to a number of reasons, one being 126.96.36.199 shows the resulting ranges after the exclusions hwere 188.8.131.52 does not.