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DHCP with more than 254 addresses

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DHCP with more than 254 addresses

I have an MX65 and i would like to setup 700 computers connected through DHCP. How would i do this? 

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Re: DHCP with more than 254 addresses

@tmontano

 

You will find that this CIDR calculator is a useful tool

 

 

Robin St.Clair | Principal, Caithness Analytics | @uberseehandel

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Re: DHCP with more than 254 addresses

Depending on how your network topology is set up.

 

If its a flat network, I assume you have a network setup to hold over 700 IP addresses such as a class B network, then the MX's DHCP will give out addresses within that subnet. All you have to do is turn on DHCP for that VLAN holding the 700 computers.

 

If you're using /24 subnet, then you can only have 253 addresses (one is the MX and the other two unusable by hosts). If your network is flat, then you probably need a /22 which hold 1022 hosts.

 

However, you might want to consider creating VLANs to better manage those 700 computers in an organized way. You can have a DHCP server for each VLAN on the MX.


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CCNP Certified and Meraki Operator
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Re: DHCP with more than 254 addresses

As @Chris_M has stated a /24 cannot handle more than 256 addresses. You need to change to a different class of network. If you don't know what a different class network is I suggest you attend a course on basic networking otherwise you risk having a network thats incorrectly setup and probably insecure.

 

Good luck!

Meraki CMNO, Ruckus WISE, Sonicwall CSSA, Allied Telesis CASE & CAI
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Re: DHCP with more than 254 addresses


@tmontano wrote:

I have an MX65 and i would like to setup 700 computers connected through DHCP. How would i do this? 


That's a lot more clients than is recommended for that model. I would suggest upgrading. Also, as others have pointed out, you can't do that in a /24. I'd recommend either creating multiple VLANs on /24s, or one /22.

BHC Resorts IT Department
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Re: DHCP with more than 254 addresses

As above, I'd definitely look at upgrading from an MX65 if you're going to have 700 active clients on the network behind the MX. An MX100/250 would suit you better, especially if you're using all advanced security features. I'd recommend reaching out to your Meraki sales rep who will be able to assist you with rightsizing your MX for your environment. 

Eliot F | Simplifying IT with Cloud Solutions
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Re: DHCP with more than 254 addresses

@tmontano

 

You will find that this CIDR calculator is a useful tool

 

 

Robin St.Clair | Principal, Caithness Analytics | @uberseehandel

View solution in original post

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Re: DHCP with more than 254 addresses


@BHC_RESORTSwrote:

@tmontano wrote:

I have an MX65 and i would like to setup 700 computers connected through DHCP. How would i do this? 


That's a lot more clients than is recommended for that model. I would suggest upgrading. Also, as others have pointed out, you can't do that in a /24. I'd recommend either creating multiple VLANs on /24s, or one /22.


Will it die? Or choke? I see the recommended max is 50 clients, right? What kind of performance degradation are we talking about? Also, we are talking about active clients, right? Not just cell phones and tablets passively connected I hope.

Kind of a big deal

Re: DHCP with more than 254 addresses


@CharlesIsWorkinwrote:

@BHC_RESORTSwrote:

@tmontano wrote:

I have an MX65 and i would like to setup 700 computers connected through DHCP. How would i do this? 


That's a lot more clients than is recommended for that model. I would suggest upgrading. Also, as others have pointed out, you can't do that in a /24. I'd recommend either creating multiple VLANs on /24s, or one /22.


Will it die? Or choke? I see the recommended max is 50 clients, right? What kind of performance degradation are we talking about? Also, we are talking about active clients, right? Not just cell phones and tablets passively connected I hope.


If they don't do anything you can have huge numbers connected. It isn't just the MX65, there isthe available bandwidth provides by the ISP to consider as well.

 

Based on the questions you are asking and the information you have provided, you would be better off getting a consultant involved, it will save you money and aggravation in the long run.

Robin St.Clair | Principal, Caithness Analytics | @uberseehandel
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Re: DHCP with more than 254 addresses


@Uberseehandelwrote:

@CharlesIsWorkinwrote:
Will it die? Or choke? I see the recommended max is 50 clients, right? What kind of performance degradation are we talking about? Also, we are talking about active clients, right? Not just cell phones and tablets passively connected I hope.

If they don't do anything you can have huge numbers connected. It isn't just the MX65, there isthe available bandwidth provides by the ISP to consider as well.

 

Based on the questions you are asking and the information you have provided, you would be better off getting a consultant involved, it will save you money and aggravation in the long run.


Right, we do have some consultation in place with a third party IT company. And some minimal traffic shaping in place also. We are nowhere near saturating our internet connection pipeline, but I was just wondering how much heavy lifting can the MX64 and 65 do beyond its stated capabilities. Our business has 

 

Like in the OP's case, this seems to be taken to the extreme. I am curious to see how it turns out in the real world application. I assume he has a WSUS server somewhere in there....and hopefully not many VoIP users concurrently active. Also if he has some kind of cloud security camera solution that isn't on the lan, his traffic shaping and even DHCP on the mx might have a tough time keeping up.

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