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New Member

DHCP not taking by Host PC

Cisco WS-C3560X-24P configured as DHCP Server (12.2(55)SE5)  (L3 SW).   Cisco C3560 connected to Server Switch (15.0(2)SE4).  When i create VLAN interface, it get assigned with DHCP IP . But when PC connected it's not taking IP from DHCP Server.

 

Stuck from here ..

*Mar  1 13:06:35.431: DHCPD: unicasting BOOTREPLY for client 55ee.7525.97d3 to relay 172.20.24.27. 

 

For VLAN,

*Mar  1 00:01:18.198: %DHCP-6-ADDRESS_ASSIGN: Interface Vlan125 assigned DHCP address 172.20.24.20, mask 255.255.255                                .128, hostname SW1

 

... If PC directly connected to Server switch, PC 's getting IP without any issues.   Since DHCP running on same VLAN, helper address not configured

 

 

Any suggestion friends ?

 

Thanks,

Charith

 

7 REPLIES
New Member

Can you share a diagram and

Can you share a diagram and relevant configuration files?

Is Vlan interface built on

Is Vlan interface built on 3560 switch or Server Switch or both?

Which switch is the pc being plugged into when dhcp is failing?

 

If the 3560 is the dhcp server and you are plugging the pc into the Server swtich and successfully obtaining an ip address from the dhcp server/3560 switch, that indicates the vlan 125 is being trunked between the switches.  Then plugging the pc into the 3560 swtich/dhcp server and it fails, that sounds like the access port where the pc is connected is not configured with the correct vlan.

 

 

New Member

Yep vlan interfaces built on

Yep vlan interfaces built on 3560 switch (DHCP SErver) . Pc plugged to other switch.    I have assigned correct vlan to  specific port using #swithcport access vlan  command ...

 

Thanks for the reply !!

 

Silver

Are you using dhcp snooping

Are you using dhcp snooping or arp inspection? If you are using these try to disable them.

 

Thanks

John

New Member

no john .. snooping or arp

no john .. snooping or arp inspection not enabled..

 

Thanks..

New Member

Can you please check if

Can you please check if service dhcp is enabled.

Are you able to share a debug

Are you able to share a debug of DHCP. to understand the issue ???

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