GroupStudy.com GroupStudy.com - A virtual community of network engineers
 Home  BookStore  StudyNotes  Links  Archives  StudyRooms  HelpWanted  Discounts  Login
Re: IOS DHCP issue posted 01/15/2007
[Chronological Index] [Thread Index] [Top] [Date Prev][Date Next] [Thread Prev][Thread Next]


If you study DHCP packets carefully, you will notice that network mask is
not carried in any DHCP packets.

On 1/15/07, Tony Schaffran <groupstudy@xxxxxxxxxxxxxxxx> wrote:
>
> There is still a problem with your dhcp pool not matching the subnet of
> vlan3.
>
> Tony Schaffran
> Network Analyst
> CCIE #11071
> CCNP, CCNA, CCDA,
> NNCDS, NNCSS, CNE, MCSE
>
> www.cconlinelabs.com
> Your #1 choice for online Cisco rack rentals.
>
>
>
> -----Original Message-----
> From: nobody@xxxxxxxxxxxxxx [mailto:nobody@xxxxxxxxxxxxxx] On Behalf Of
> Jim
> Sent: Monday, January 15, 2007 11:21 AM
> To: ccie anees
> Cc: ccielab@xxxxxxxxxxxxxx
> Subject: Re: IOS DHCP issue
>
>
> I tested the config through lab,  it seems to work.   Just like others
> pointed to, there was issue before router rip betweening R1 and sw1,
> because, R1 was sending unicast dhcp-offers to 129.1.3.7, but it didn't
> have
> that route.  So it had no-where to send.  After turning on rip, it starts
> working.    Here is the configuration and the debug output.
>
>
> R1
> ####
> interface FastEthernet0/0
> ip address 129.1.17.1 255.255.255.0
> !
> no ip dhcp conflict logging
> ip dhcp excluded-address 129.1.3.1 129.1.3.2
> ip dhcp excluded-address 129.1.3.4 129.1.3.254
> !
> ip dhcp pool R3_Pool
>   network 129.1.3.0 255.255.255.0
>   default-router 129.1.3.7
> !
> router rip
> no auto-summ
> version 2
> network 129.1.0.0
>
> SW1
> ######
> interface Vlan17
> ip address 129.1.17.7 255.255.255.0
> interface Vlan3
> ip address 129.1.3.7 255.255.255.128
> ip helper-address 129.1.17.1
> router rip
> no auto-summ
> version 2
> network 129.1.0.0
>
> R3
> ###
> interface FastEthernet3/0
> ip address dhcp
>
>
> Rack2R3(config)#int fa 0/0
> Rack2R3(config-if)#ip add dhcp
> Rack2R3(config-if)#
> *Nov 30 16:41:52.994: %DHCP-6-ADDRESS_ASSIGN: Interface FastEthernet0/0
> assigned DHCP address 129.1.3.3, mask 255.255.255.0, hostname Rack2R3
>
>
> Rack2SW1(config-if)#
> 2d21h: DHCPD: setting giaddr to 129.1.3.7.
> 2d21h: DHCPD: BOOTREQUEST from
>
> 0063.6973.636f.2d30.3030.392e.3763.3735.2e35.3138.312d.4661.302f.30forwarded
> to
> 129.1.17.1.
> 2d21h: DHCPD: forwarding BOOTREPLY to client 0009.7c75.5181.
> 2d21h: DHCPD: broadcasting BOOTREPLY to client 0009.7c75.5181.
> 2d21h: DHCPD: setting giaddr to 129.1.3.7.
> 2d21h: DHCPD: BOOTREQUEST from
>
> 0063.6973.636f.2d30.3030.392e.3763.3735.2e35.3138.312d.4661.302f.30forwarded
> to
> 129.1.17.1.
> 2d21h: DHCPD: forwarding BOOTREPLY to client 0009.7c75.5181.
> 2d21h: DHCPD: broadcasting BOOTREPLY to client 0009.7c75.5181.
>
> Rack2R1#
> *Mar  3 21:52:27.594: DHCPD: DHCPDISCOVER received from client
> 0063.6973.636f.2d30.3030.392e.3763.3735.2e35.3138.312d.4661.302f.30through
> relay 129.1.3.7.
> *Mar  3 21:52:29.594: DHCPD: Sending DHCPOFFER to client
> 0063.6973.636f.2d30.3030.392e.3763.3735.2e35.3138.312d.4661.302f.30 (
> 129.1.3.3).
> *Mar  3 21:52:29.594: DHCPD: unicasting BOOTREPLY for client
> 0009.7c75.5181to relay
> 129.1.3.7.
> *Mar  3 21:52:29.602: DHCPD: DHCPREQUEST received from client
> 0063.6973.636f.2d30.3030.392e.3763.3735.2e35.3138.312d.4661.302f.30.
> *Mar  3 21:52:29.602: DHCPD: Sending DHCPACK to client
> 0063.6973.636f.2d30.3030.392e.3763.3735.2e35.3138.312d.4661.302f.30 (
> 129.1.3.3).
> *Mar  3 21:52:29.602: DHCPD: unicasting BOOTREPLY for client
> 0009.7c75.5181to relay
> 129.1.3.7.
>
> _______________________________________________________________________
> Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html
>
> _______________________________________________________________________
> Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html