how to configure dhcp server in extreme switch and if you multiple vlan in switch how to apply dhcp in all vlan?

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Sumit Johari

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Posted 4 years ago

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Johan Hendrikx

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Like this:

configure vlan <VLAN> ipadress 10.0.1.254 255.255.255.0

configure vlan <VLAN> dhcp-address-range 10.0.1.1 - 10.0.1.50
configure vlan <VLAN> dhcp-lease-timer 28800
configure vlan <VLAN> dhcp-options default-gateway 10.0.1.254
configure vlan <VLAN> dhcp-options dns-server 8.8.8.8
configure vlan <VLAN> dhcp-options dns-server secondary 4.4.4.4
enable dhcp ports  <port range>  vlan <VLAN>

This have to be done for every vlan

(Edited)
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Nitesh Verma

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Hi sir, if i have dhcp server configuration in my extreme switch.
but i want to take my dhcp vlan 100 from my extreme switch tagged port 16 (where multiple service vlan are tagged) to my another cisco switch.

is it possible without "enable dhcp port 16 vlan xyz" will work (because there are multiple vlan are tagged at 16th port and i do not want to enable dhcp port 16 and want to use 100 vlan on outside switch untagged port)
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Sumit Johari

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Dear Johan,

i am using dhcp server (window server 2012) and only want to  change all vlan take dhcp ip address from this server.
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Johan Hendrikx

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Oke:

configure bootprelay add  >dhcpserver>

enable bootprelay vlan <vlan>


or enable bootprelay all

(Edited)
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Sumit Johari

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thanks johan,

I am currently using one dhcp in our environment need to change his ip address.what is command  to change dhcp server ip address.
after changing the dhcp ip address all vlan by default take ip address from the new dhcp server.
its not required to use enable bootprelay commands for all vlan .because i have already enable bootprelay commands for all vlan.

my current config_


configure bootprelay add <IP> vr VR-Default
configure bootprelay dhcp-agent information check vr VR-Default
enable bootprelay vr VR-Default vlan <name>
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Johan Hendrikx

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To change the bootprelay addres:

configure bootprelay add <new-ipaddress>

configure bootprelay delete <old-ipaddress>

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Sumit Johari

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Oke.

By Default all vlan take ip address from this new dhcp server add
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Sumit Johari

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Hi Johan,

If i will add a new dhcp server without delete the old dhcp server it will give any impact.
@old server i will shut down but server entry will be remain and switch.
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Sumit Johari

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Hi Johan,

We are using the vrrp between the extreme l3 switch please let me know which switch i will do the change first dhcp server ip address?


Regards
Sumit
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Patrick Voss, Alum

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Here is an article from our knowledge website explaining how to configure a DHCP server for a VLAN

Browser View: https://gtacknowledge.extremenetworks.com/articles/How_To/How-to-configure-the-DHCP-server-on-a-VLAN-in-EXOS
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Kawawa, GTAC

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Hi Summit, in addition to what Johan has outlined above,

A VLAN will only request an IP address from a DHCP server that is configured globally, or explicitly enabled on that particular VLAN.  In the two commands below, the first command adds a DHCP server to the vlan v1_vlan meaning, the switch can attempt to solicit an IP address from 192.168.0.1 for any client within v1_vlan.  In the second command, the DHCP server 10.0.0.1 is enabled globally.  What this means is that the clients in v1_vlan now have access to a second DHCP Server (10.0.0.1).

configure bootprelay "v1_vlan" add 192.168.0.1
configure bootprelay add 10.0.0.1

Whether or not an IP address will be assigned to a client is not important at this stage, because the DHCP server has the responsibility to assign the correct IP address in the correct subnet by choosing the DHCP DISCOVER packet to respond to. Similarly, the DHCP client is responsible for accepting the appropriate DHCP OFFER from the DHCP server.  Extreme's switches handle multiple DHCPs configured for a single VLAN using Sequential mode where the switch relays a DHCP DISCOVER packet for the first IP.  If there is no offer from the Server after three tries, the Switch then attempts the second IP until an offer is received.

I hope the above answer two of your questions.  Finally, you'd have to elaborate a little further on how you've deployed VRRP.  In an idea situation that would be an entirely different set of devices altogether, and if they are, then the DHCP packets simply transit through them enroute to the DHCP Server
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Sumit Johari

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Thanks.....
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Jesús Aguilar

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Hi everybody.

I have a question: Is it necessary to configure "enable bootprelay vlan X" in both SW ́s:  
Acces SW (Layer 2) and in the Core SW (Layer 3), 
Or is enough only in Core SW (Layer 
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Patrick Voss, Alum

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Bootprelay needs to be enabled on the switch that is routing. As long as the device has L2 connectivity up to the routing switch bootprelay will take over from there.
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Jesús Aguilar

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Thank You Patrick Voss