I have a subnet of x.x.77.128/25 that uses a gateway of x.x.77.129. This subnet feeds up addresses from x.x.77.130 to x.x.77.254. Now, I would like to exclude the range of addresses from x.x.77.131 to x.x.77.140 from the DHCP list. I am in the IP → DHCP Server → part of the RouterOS WinBox software. I have clicked around for a while now trying to find exclusions to the DHCP host, but so far I have not found anything. My only option, that I can find so far, is to create another subnet within this subnet to exclude the addresses. This seems to be more work than it seems just to exclude a few addresses. Does anyone have any ideas on how to exclude the addresses? I added a screenshot of what I am looking at on the server. It is entirely possible that I am not even in the correct place. This is really my first time trying to use this product. This was all set up by a 3rd party who is no longer affiliated with me. Therefore my current learning curve on this product is basically a vertical line.
set up pool for use in the DHCP server that excludes the ranges you do not want to give out.
like 192.168.0.22-192.168.0.40 this pool have only 18 addresses in it.
Thank you to both Shayan and Janisk for your replies. I am still trying to wrap my head around this one, so I am attaching a better screen shot of what is already set up. Again, someone else set all this up, and now they are no longer reachable therefore this has fallen onto me for repair.
There is already a range setup, I have obscured the actual IP addresses, but you should be able to see what I am alluding to with the screen shot. The currently established range includes the addresses I wish to remove from the pool. For example, my 192.168.77.128/25 pool, with the gateway of 192.168.77.129, is handing out addresses starting at 192.168.77.130 and going through 192.168.77.254. I would like to exclude the addresses from 192.168.77.131 through 192.168.77.140. In order to accomplish this, what do I change in the DHCP Server? I thought there would be an exclusion list or something, but it seems to hand out addresses based on subnet, not range. Do I need to modify my subnet or do I just enter the range as Janisk suggested? It is at this point that I am getting myself confused and having a hard time finding documentation on how to make changes to the established and working system.
Winbox example.png
Did you look in IP->Pool? That’s where the pool is configured. It’s then referenced by server in IP->DHCP Server->DHCP (first tab), field Address Pool.
The server configuration is where you set the behavior of the service itself - what interface to listen on, what pool to use, what lease time to give, static leases, etc…
The networks are how you define “scopes” - this is where you set the values of the options (and which options) to return for hosts falling inside of that scope. You want to define the network properly here - use the correct /25 netmask, the correct default GW, dns server, etc…
The IP pool is basically a list of the addresses available for dynamic assignment - you could make a pool that only has 3 addresses in it, and once all 3 are leased by clients, the DHCP server can’t assign any more dynamic IPs. If you need to punch holes in the range, you can break up the pool into several smaller ranges - but it’s these ranges that define which IPs are to be used as dynamic addresses.
Thank you to ZeroByte and Sob for their posts. With the help of everyone who responded to my posts, I believe I have now figured out how to exclude the IP addresses. Here is what I did:
In the IP → Pool setting, I changed the DHCP scope to exclude the IP addresses that I want to make static. In the same area, I created a new Pool and gave it a name then the range of static IP addresses, mainly for documentation purposes. Using this theory, I shouldn’t have to make any changes in the IP → DHCP Server tab, as it will continue to use the same settings, just with the newly defined range.
Did I miss anything? Will the range of static IP addresses cause any problems if they are not tied to anything in the DHCP server? Again, I did that mainly so a year from now, I remember why the DHCP scope is set up without those addresses.
An unused IP pool just sitting there won’t cause any problems, as nothing ever asks the pool for addresses.
Another option might be to create static leases for your static hosts, leaving the hosts themselves configured to use DHCP.
The easy way to do this is to let a static host obtain a lease, then go into the Mikrotik’s leases tab, edit the static hosts’s dynamic lease and hit the “Make Static” button. Close the window and open the static lease (I forget why this step is necessary, but I recall that it is) and then change the IP address to whatever static address you like. Finally, on the static host, do a dhcp release and renew. It will now have the static IP.
Of course you could just add the static lease manually and fill in the blanks, but starting with a dynamic entry is the easy/lazy way to do it without having to type in MAC addresses and stuff. You can also label your static leases with comments.
I’m not saying you need to switch to this method - it’s just another method you might like / another “tool in the toolbox” so to speak.