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2960 Switch with DHCP configured

sgrinnall
Level 1
Level 1

Hi,

we have an issue with a single device picking up DHCP.  PCs on the vLAN are picking up DHCP addresses fine, however another device does not.  If I disable the Cisco DHCP on that vLAN and use an alternative DHCP source, (I downloaded a freebe DHCP server app for my laptop) it works fine.

The DHCP pool is set-up

ip dhcp pool vlan1

   network 192.168.50.0 255.255.255.0

   domain-name Fred.co.uk

   dns-server 192.168.0.150 192.168.0.250

   default-router 192.168.50.254

   lease 3

ip dhcp excluded-address 192.168.50.1 192.168.50.50

ip dhcp excluded-address 192.168.50.60 192.168.50.254

and ports are set up as:-

interface FastEthernet0/2

switchport mode access

spanning-tree portfast

and vLAN 1 as

interface Vlan1

description STORE

ip address 192.168.50.253 255.255.255.0

no ip route-cache

7 Replies 7

sgrinnall
Level 1
Level 1

Continued...

I scratching my head on this one, any help is much appreciated

There are only nine addresses available in the pool is that enough?

DHCP-debugging could also give some hints: "deb ip dhcp server events"

-- 
Don't stop after you've improved your network! Improve the world by lending money to the working poor:
http://www.kiva.org/invitedby/karsteni

thanks Karsten.Iwen

yes, 9 is plenty of addesses we are only using this for a couple of devices.

On this device, running "SHO IP DHCP BIND" lists only 2 devices.  I can see the device is connected fine, for example I can see the Mac address of the device with "Sho MAc Address-Table"

I will try the DHCP debugging now

I added the DEB IP DHCP SERVER EVENTS command and can see activity if I release and renew the IP on a PC fine.

Restarting the FalconXT device we have there is no DHCP activity at all.  When using the alternative DHCP server from my PC it picks up an address immediatly

Switch#

*Mar  1 00:06:24.416: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/9, changed state to down

*Mar  1 00:06:25.422: %LINK-3-UPDOWN: Interface FastEthernet0/9, changed state to down

*Mar  1 00:06:32.167: %LINK-3-UPDOWN: Interface FastEthernet0/9, changed state to up

*Mar  1 00:06:32.167: DHCPD: interface FastEthernet0/9 coming up

*Mar  1 00:06:33.174: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/9, changed state to up

*Mar  1 00:06:49.741: DHCPD: checking for expired leases.

Switch#

Switch#

*Mar  1 00:08:49.748: DHCPD: checking for expired leases.

Hi,

So when releasing/renewing on the device you see no output in debug ip dhcp server event on the switch ?

On which port is this device connected? post the output of sh interface x/x switchport for this interface

Regards

Alain

Don't forget to rate helpful posts.

Don't forget to rate helpful posts.

   lease 3

Lease is 3 days????  And you have 8 allowed IP address?  (Personally, I don't see the logic or insanity for this.  If it's only 8 allowable IP addresses and lease time is 3 days, I'd configure the DHCP to be static.) 

Post the output to the command "sh ip dhcp bind".

jawad-mukhtar
Level 4
Level 4

Try Giving this command

ip dhcp-server 192.168.50.253

ip dhcp snooping

interface Vlan1

ip helper-address 192.168.50.253

Jawad

Jawad
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