Catalyst 3560-X Switch to act as a DHCP Server

Shane Baron Caudill · ‎04-27-2012

I'm attempting to configure a Catalyst 3560-X Switch to act as a DHCP Server. There is documentation that supports this feature. Below is my config procedure however after the completed procedue no IPs are handed out to clients. Any feedback is much appreciated.

Network Subnet : 172.20.20.0 255.255.255.0

Gateway Address : 172.20.20.1

DNS Server : 172.20.20.1

DHCP Pool : 172.20.20.100 to 172.20.20.105

Excluded Addresses : 172.20.20.1 to 172.20.20.99 & 172.20.20.106 to 172.20.20.254

Lease : 23

Commands for config :

#config t

#int FastEthernet0/0

#ip address 172.20.20.2 255.255.255.0

#no shut

#exit

#service dhcp

#ip dhcp pool voice

#network 172.20.20.0 /24

#dns-server 172.20.20.1

#default-router 172.20.20.1

#lease 23

#exit

#ip dhcp excluded-address 172.20.20.1 172.20.20.99

#ip dhcp excluded-address 172.20.20.106 172.20.20.254

#exit

#write mem

I'm attempting to configure a Catalyst 3560-X Switch to act as a DHCP Server. There is documentation that supports this feature. Below is my config procedure however after the completed procedue no IPs are handed out to clients. Any feedback is much appreciated.

Network Subnet : 172.20.20.0 255.255.255.0

Gateway Address : 172.20.20.1

DNS Server : 172.20.20.1

DHCP Pool : 172.20.20.100 to 172.20.20.105

Excluded Addresses : 172.20.20.1 to 172.20.20.99 & 172.20.20.106 to 172.20.20.254

Lease : 23

Commands for config :

#config t

#int FastEthernet0/0

#ip address 172.20.20.2 255.255.255.0

#no shut

#exit

#service dhcp

#ip dhcp pool voice

#network 172.20.20.0 /24

#dns-server 172.20.20.1

#default-router 172.20.20.1

#lease 23

#exit

#ip dhcp excluded-address 172.20.20.1 172.20.20.99

#ip dhcp excluded-address 172.20.20.106 172.20.20.254

#exit

#write mem

p.mcgowan · ‎04-27-2012

Rather than have the L3 address on a physical interface it is best to make it an SVI, if the interface goes down you have lost your gateway;

interface vlan 10

ip address 172.20.20.2 255.255.255.0

also change the config of your default-router to be a router, not the DNS server;

ip dhcp pool voice

default-router 172.20.20.2