08-29-2024 08:49 AM
Hello Professionals,
Recently I'm having an DHCP issue with my C9300 switch.
Switch config is :
ip dhcp pool Wireless
network 10.250.20.0 255.255.255.0
network 10.250.24.0 255.255.255.128 secondary
default-router 10.250.20.1
Whenever user tries to connect wireless, client device gets IP address from 10.250.20.1 which is switch's SVI.
However, from few days ago, whenever device requests IP, it provides multiple addresses with one mac address.
>> show ip arp | inc aabb.ccdd.0011
10.250.20.38 aabb.ccdd.0011
10.250.24.89 aabb.ccdd.0011
10.250.24.104 aabb.ccdd.0011
I read about secondary IP pool is not recommended, but it is required at least for now..
Could anyone help..?
Thank you for providing your time.
08-29-2024 08:53 AM
you config need
1- dhcp exclude for VLAN SVI
2- secondary IP under VLAN SVI
also try reduce the leased time to 30 min only
MHM
08-29-2024 08:59 AM
Hello, thank you for reaching me!
1) dhcp exclude for VLAN SVI:
ip dhcp excluded-address 10.250.20.1 10.250.20.10
ip dhcp excluded-address 10.250.20.254
ip dhcp excluded-address 10.250.24.1
2) Secondary IP under VLAN SVI
interface Vlan20
description Wireless
ip address 10.250.24.1 255.255.255.128 secondary
ip address 10.250.20.1 255.255.255.0
My current lease time is 0 12 59, I will change it to 0 0 30.
Thank you,
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