CSCsw72963 - ASA local address pools should support DHCP reservations/assignments

[ayakoleb]

Does  ASA 5505 could supply DHCP server and mac address reservation ?

please any advice and appreciate if their is any documents that can help . 

Thanks 

[olivier.vigneresse]

Trawlling through the CSC and Google, it looks like this (beeing able to configure DHCP reservations on an ASA) has been a feature requested for years. 

For what it's worth, the rationale from my point of view is that several small and medium size business clients have an ASA and a mixture of L2 switches and WifiAP as their network infrastructure; DHCP serving functionality is best done on the ASA but not being able to add reservations is a pain as you then need to manage a mix of DHCP and static addresses, with the potential for human errors that this entails.

And explaining that it is not available on a business-grade ASA costing $100's when they usually have it on their $30 broadband gateway at home is difficult :-(

Can someone at Cisco shed some light on how likely it is to actually be implemented soon?

[BRANDON TAYLOR]

Any update on this?  Had to put in a far more inexpensive device to get this resolved and the ASA is now on the shelf...

[olivier.vigneresse]

I have no update and in a bit of a rut: Google does not seem to have any meaningful information, and I don't have access to an Account Manager / Product Manager at Cisco who might shed light on this.

If you or anyone knows how to get the official line from Cisco, I'd sure welcome it!

[systems]

Still, no updates?

[wwbarnes]

Seems like the ASA has had this issue for years and they have no intension of correcting it.  Just saying!

[wwbarnes]

---

@systems wrote:

Still, no updates?

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Seems like the ASA has had this issue for years and they have no intension of correcting it.  Just saying!

[Jay Johnston · Accepted solution]

This feature is now supported on ASA in version 9.13(1) and later

Example:

Magnus-5506-Desk# sh run dhcpd
dhcpd dns 192.168.1.22
dhcpd domain cisco.com
dhcpd option 4 ip 172.18.124.1
!
dhcpd address 192.168.100.100-192.168.100.200 inside
dhcpd enable inside
dhcpd reserve-address 192.168.100.199 ecb5.fa0f.988b inside
!
Magnus-5506-Desk#

[Hausley88]

But it still not working fine.

It wont not bind some MAC-addresses.

It works for most of my clients, but I am having two clients (and of course I have verified the hw-address 100s of times) that are not getting the proper reserved address.

Don't ask me why?

[Jay Johnston]

If you're finding that this feature doesn't seem to work for just a few addresses but works ok for others, it is best to open a TAC case so they can dig into the problem and get the solution

[Hausley88]

Cisco says bug CSCvy09436 is fixed. And yes, they are right it works for these specific addresses, but now it no longer works for all other addresses > so what the f...?

[Hausley88]

And another story: Why cant I make reservations outside the Pool? When I do this, it works for the moment, but once I reload the ASA it removes or ignores all reservations outside the Pool----

[Jay Johnston]

The DHCP reserve address feature is an extension of the DHCP pool functionality and requires the reserved address be from a specified DHCP pool. See the command reference for the command:
https://www.cisco.com/c/en/us/td/docs/security/asa/asa-cli-reference/A-H/asa-command-ref-A-H/m_dh-dm.html#wp1603069952

[Hausley88]

I understand, that this is, what the docu says.

But I do not understand why Cisco would limit the feature to only work for addresses within the pool.

And as I said above, it works with a little workaround.
Open the pool to the full subnet, make the reservations, then shrink the pool to your needs....
It then assigns even the reservations outside the pool, BUT on the next ASA reload it kicks the reservation lines that are outside the pool.