dhcp cylic allocation for particular vlan

  • 7 December 2015
  • 5 replies

we have extreme switch with following configuration

create vlan "vlan2001"
configure vlan vlan2001 tag 2001
configure vlan vlan2001 add ports 21-24 tagged
configure vlan vlan2001 add ports 10 untagged
configure vlan vlan2001 ipaddress
enable ipforwarding vlan vlan2001
configure vlan vlan2001 dhcp-address-range -
configure vlan vlan2001 dhcp-options default-gateway
configure vlan vlan2001 dhcp-options dns-server
enable dhcp ports 21-24 vlan vlan2001
# show vlan2001 dhcp-config
DHCP Address Range :>
Netlogin Lease Timer : Not configured (Default = 10 seconds)
DHCP Lease Timer : Not configured (Default = 7200 seconds)
Default Gateway :
Primary DNS Server :
Ports DHCP Enabled : 10, 21-24

Is it possible to tell switch to cycle through IP's .
say I have 20 devices . hey got
after two hours they should get
Next allocations will be 43-62 , 63-82 , (83-100 ,3,4) , 5-24 , ...
It should give new IP's till range gets exhausted .

Is that or something similiar possible ?

5 replies

Userlevel 1
Not sure if you can get them to accept the next IP address in the range but you can adjust the lease.

configure vlan vlan2001 dhcp-lease-timer

I believe the defualt value is 7200 seconds, you can adjust from 0 - 4294967295

OR - maybe look into DHCP Bindings

can switch assign random IP's when DHCP lease expires ? instead of going to lowest free in range .

Userlevel 4
Typically clients will request the same IP they have at half (1/2) dhcp-lease-time. Normally DHCP servers will re-assign the client the same address (as requested by the client) since it matches the existing lease.

Userlevel 1
Can i ask why you need clients to be assigned different IP?
Actually , our systems gives acknowledgement when device changes its IP . I guess , i am asking something non-standard .