From: Tony Schaffran (groupstudy@cconlinelabs.com)
Date: Mon Jan 15 2007 - 19:28:52 ART
I beg to differ.
How do you think the mask gets set?
If you notice, the mask was set to the mask that was configured in the DHCP
pool on R1.
Tony Schaffran
Network Analyst
CCIE #11071
CCNP, CCNA, CCDA,
NNCDS, NNCSS, CNE, MCSE
www.cconlinelabs.com <http://www.cconlinelabs.com/>
Your #1 choice for online Cisco rack rentals.
-----Original Message-----
From: Jian Gu [mailto:guxiaojian@gmail.com]
Sent: Monday, January 15, 2007 2:04 PM
To: Tony Schaffran
Cc: Jim; ccie anees; ccielab@groupstudy.com
Subject: Re: IOS DHCP issue
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 < <mailto:groupstudy@cconlinelabs.com>
groupstudy@cconlinelabs.com> 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@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of Jim
Sent: Monday, January 15, 2007 11:21 AM
To: ccie anees
Cc: ccielab@groupstudy.com
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.30 through
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.
This archive was generated by hypermail 2.1.4 : Thu Feb 08 2007 - 23:46:56 ART