Do you use dhcp reservations?

KOM

I don't use reservations at home or at the office. For me the only benefit would be easier renumbering, and that's something I haven't needed to do in the 20+ years I've been at this company. I report directly to the owners and they want to be able to do whatever they want when they want including weekends and evenings when I'm not around. I appreciate the security aspects but the owners don't like security getting in the way of their convenience.

azdeltawye

@johnpoz
Yes, I rely heavily on DHCP reservations for firewall rules and grouping of similar devices..

Does Kea DHCP not allow for static mappings?

azdeltawye

@bmeeks said in Do you use dhcp reservations?:

To me, it is easier in such situations to use a static IP assignment....

Maybe in some cases. However, many dumb IOT devices are 'hardwired' for DHCP.

MoonKnight

@johnpoz

Yes I use lot of DHCP Static Mappings all over my VLAN's :)

johnpoz

@azdeltawye said in Do you use dhcp reservations?:

Does Kea DHCP not allow for static mappings?

It does, but does not register them in unbound for dns as of yet.

ahking19

Yes, for all my home VLANs except the Guest one.

johnpoz

@maverickws said in Do you use dhcp reservations?:

Personally I most times call them "static mappings" or "arp mappings".

Why I called it out and hope make clear what I was talking about.. The static mapping term seems to be newer wording.. Us old farts, at least in my part of the world use reservation - because that is what they are, they are reservation for that mac to get this specific IP.. Kind of like when you make a reservation at a restraunt for table by the window..

But maybe it also just regions of the world use different terms?

That is another thing that is curious ;) maybe I could start another poll - hehehe

static mapping and arp mapping don't make a lot sense to me... Because that is not what it is, its a "reservation" on the dhcp server to give client X ip Y..

And unlike the Seinfeld episode, a dhcp server normally knows how to hold a reservation ;)

Youtube Video

bmeeks

@johnpoz said in Do you use dhcp reservations?:

Us old farts, at least in my part of the world use reservation

Welcome to the official pfSense old farts club . We can be the charter members!

Phizix

@johnpoz
I use them extensively. I also have Aliases for groups of addresses that I put them into, so I can make rules. Example Desktops, Laptops, and a combined alias of Computers (Desktop + Laptops). IOT devices, etc . . . .

I leave DHCP assigned to a certain range for new devices. I periodically (about once per week) look for any leases in that range (and hunt them down and kill them - J/K). If they are a new device that needs to be statically mapped I do so. If it is some temporary device I just make a mental note of it.

Phizix

gauthig

@johnpoz
This is the real problem with migrating to Kea at this time. It is irrespective of using static mappings (or reservations), fully DHCP or a combination of both on each subnet.

A good network should be using SSL on servers/services. An API call or just using a web browser breaks the validation of your cert if you use IP address instead of a FQDN. Modern browsers also are stopping you by forcing an acknowledgement to go to the site if you did not use the correct name in the URL, i.e. IP address.

One way around this is to set up all servers, like NAS, Plex, Home Assistant, Grafana, Influx.... (whatever you have on your local network), with static IP's (or static mappings) and then manually create an entry in unbound. But that extra work, more like BOUND and not unbound.

Let's just keep asking to add the KEA to unbound integration as a priority.
In the meantime, I'll be watching for any isc-dhcp CVE's and determine if I go the manual BOUND route or not.

SteveITS

@johnpoz May be sample bias as most users here are advanced.

@bmeeks Two reasons for us…

Windows 10 1607 feature update IIRC had a high tendency to (apparently) reset/reinstall the network adapter and therefore lose static IP settings. Have also seen this with resetting printers or other hardware.
if you need to change your subnet or especially mask it saves time touching each device to update manually.

johnpoz

@SteveITS said in Do you use dhcp reservations?:

May be sample bias as most users here are advanced.

That was my whole thought/point to be honest, I would think users of pfsense would lean towards being more advanced than your typical home router, what is an IP user ;)

Which is why I would think using reservations would pretty common.. Which so far that is what the poll is showing as well.

NogBadTheBad

I do, most of my devices are dhcp reservations.

After the update I and bet a lot of other people went back to the old dhcp server.

maverickws

@johnpoz said in Do you use dhcp reservations?:

static mapping and arp mapping don't make a lot sense to me... Because that is not what it is, its a "reservation" on the dhcp server to give client X ip Y..

eheh well I can tell you straight why I called them that. One of my first jobs was on the network department of a big local ISP. over 90% of CPE were Cisco devices managed by us. If you were adding a reservation you'd go with the command arp <ip> <mac> etc so that's why we called them "static arps" if anyone needed a reservation we'd go with "add an arp". Static only in the sense it's quicker said and a bit shorter word than re-ser-va-tion. Even translated to PT eheh but again this is slang.
Won't find me arguing if one is better than the other, main thing is people understand what it does, I've heard calling it so many things.

johnpoz

@maverickws And what cisco is that, that is not how you would make sure a device gets a specific IP out of the pool of dhcp running the cisco device.

Would be something like this

ip dhcp excluded-address 192.168.1.10

ip dhcp pool CLIENT_10
hardware-address 0034.121b.0c19
host 192.168.1.10 255.255.255.0

That is how you would set a static arp.. That isn't going to have dhcp hand out anything specific for a specific device.

maverickws

@johnpoz that was how we'd start the DHCP and establish a range for the pool instead of host.
I haven't been much around cisco lately but I'm pretty sure that was the command to add a reservation. I am probably mixing stuff. Let me check my notes!

maverickws

@johnpoz said in Do you use dhcp reservations?:

That is how you would set a static arp.. That isn't going to have dhcp hand out anything specific for a specific device.

Ok just checked so we didn't do it that way exactly. We'd create the ip DHCP pool and then invoke a static-bindings file that had the static bindings for that pool.
Part of my notes are not clear to me today, because I also have a whole part on adding ARP IP to Mac address mappings. Not sure if for quicker resolution, but I actually remember we used this plenty.

johnpoz

@maverickws sure static aps are handy, etc.. But not really a "reservation" ;)

But sure they could go hand and hand with each other.

You find different terms all over the planet for sure, as long as you can convey what it is your actually talking about - doesn't really matter.. I have always used the term transit network for example, for a network that connects routers, etc. In my new gig working noticed some colleagues call them connector networks.. Ok that works too.. same thing ;)

And they use the term kit a lot, vs just gear or specific call out switch or router, or model of the device.. Again as long as we know what each other is talking about - doesn't really matter. And I find myself using some different terms now as well ;) Because that is the terms the team uses.

maverickws

@johnpoz yeah I'm 100% with you.
Now I'm just mind bogged bc I can't remember exactly the context in we used the arp entries. Transit networks we used that too, and I believe we also used carrier networks. All and all, DHCP reservations or static mappings are in fact one of the most commonly used features. Clients get their addresses dynamically there is no need of configuring each client device, its mapping on the router and its done each device gets the proper IP. Wouldn't change a thing.

stephenw10

Yeah I use static reseervations/mappings for numerous things.

I also usually add them for devices that statically configured because it makes them resolvable (except in Kea!) and prevents me forgetting and using that IP for something else. It also means if hat device forgets it's config and falls back to dhcp it still gets the same IP.