4500 DHCP doesn't lease IP addresses

[SelamsewAmha]

Hi Dears,

I have two 4500E Distribution switches for different VLAN ranges and different DHCP IP ranges.

One of them is working good after I configured IOS DHCP Server but the other is not working; it doesn't lease IP Addresses.

I have checked all configurations with the next and nothing different but IOS version and some Crypto PKI configurations.

Does DHCP Config has anything to do with these factors?

[Mark Malone]

Can you post your dhcp config and show ip dhcp pool off the non working switch , are you connecting a laptop directly as a test

Did you debug dhcp detail to see if any packets were coming from the switch or use a wireshark ?

From experience sometimes re-applying the whole dhcp pool config can fix this , seen pools lock up before in ios and not give any addresses out

[SelamsewAmha]

Hi Mark,

Thank you for the reply,

below is the show ip dhcp pool command result

Pool VLAN2-POOL :
 Utilization mark (high/low)    : 100 / 0
 Subnet size (first/next)       : 0 / 0
 Total addresses                : 254
 Leased addresses               : 0
 Excluded addresses             : 254
 Pending event                  : none
 1 subnet is currently in the pool :
 Current index        IP address range                    Leased/Excluded/Total
 0.0.0.0              10.0.2.1         - 10.0.2.254        0     / 254   / 254

and the dhcp config is as below:

interface Vlan2
 ip address 10.0.2.2 255.255.255.0
 ip helper-address 10.0.225.4  //this is Cisco works server
 ip ospf network point-to-point
 standby 226 ip 10.0.2.1
 standby 226 timers 3 15
 standby 226 priority 110
 standby 226 authentication HSRP@XYZ

and the pool config is as below:

ip dhcp pool VLAN2-POOL
   network 10.0.2.0 255.255.255.0
   default-router 10.0.2.1
   dns-server 10.0.225.44 10.0.225.22 213.55.96.166 4.2.2.2
   option 43 hex 1f04.0a00.12fc
   domain-name *****.com

shall i remove the dhcp pool configs and reinstall it again?

[Mark Malone]

Hi just 1 thing why is there a helper address on the vlan when your trying to get your dhcp locally off the 4500, ip helper is only for clients when the dhcp server is not on the local subnet , your telling that subnet gets its dhcp off the helper but also try get it locally as there's a pool there , one may be over riding the other

If its not there for a specific reason fro cisco works can you remove that then reapply the pool again to the config and see if a client can pull an address

Have you any address exclusions set up as well in your config , the pool shows 254 addresses excluded

[SelamsewAmha]

Hi Mark,

Thank you; The problem is i misconfigured the dhcp excluded-address range.

ip dhcp excluded-address 10.0.2.128 10.0.32.254 is the one I did but it should have been

ip dhcp excluded-address 10.0.2.128 10.0.2.254

[Mark Malone]

ah good so your getting your client ips now from dhcp all working