DHCP relay change not working

[campbellknudson]

We upgraded to new dhcp servers.   A few hundred dhcp ip helper-address changes.

All good, but two routers aren't good with it.  

Changes made, written and users aren't served an address through DHCP

Can ping the dhcp servers from the routers.

There are no firewalls in the way.

When ip helper-address statement is reverted back to former dhcp server, they get an address once again.

Server1

IOS (tm) C2600 Software (C2600-D-M), Version 12.1(27b), RELEASE SOFTWARE (fc1)
Copyright (c) 1986-2005 by cisco Systems, Inc.
Compiled Tue 16-Aug-05 18:06 by pwade
Image text-base: 0x80008088, data-base: 0x8095E524

ROM: System Bootstrap, Version 11.3(2)XA3, PLATFORM SPECIFIC RELEASE SOFTWARE (fc1)

cisco 2611 (MPC860) processor (revision 0x202) with 20480K/4096K bytes of memory        .
Processor board ID JAB025102QN (879341679)
M860 processor: part number 0, mask 49
Bridging software.
X.25 software, Version 3.0.0.
2 Ethernet/IEEE 802.3 interface(s)
1 Serial network interface(s)
32K bytes of non-volatile configuration memory.
8192K bytes of processor board System flash (Read/Wri

Router 2

Cisco Internetwork Operating System Software
IOS (tm) C820 Software (C820-Y6-M), Version 12.1(5)YB5, EARLY DEPLOYMENT RELEASE SOFTWARE (fc2)
TAC Support: http://www.cisco.com/tac
Copyright (c) 1986-2002 by cisco Systems, Inc.
Compiled Fri 15-Feb-02 22:12 by yiyan
Image text-base: 0x80013170, data-base: 0x806730A0

ROM: System Bootstrap, Version 12.1(1r)XB1, RELEASE SOFTWARE (fc1)
ROM: C820 Software (C820-Y6-M), Version 12.1(5)YB5, EARLY DEPLOYMENT RELEASE SOFTWARE (fc2)

PINEF_DIST uptime is 2 weeks, 2 days, 19 hours, 0 minutes
System returned to ROM by power-on
System image file is "flash:c820-y6-mz.121-5.YB5.bin"

CISCO C827 (MPC855T) processor (revision 0x701) with 15360K/1024K bytes of memory.
Processor board ID JAD06090J7C (501068475), with hardware revision 0000
CPU rev number 5
Bridging software.
1 Ethernet/IEEE 802.3 interface(s)
1 ATM network interface(s)
128K bytes of non-volatile configuration memory.
8192K bytes of processor board System flash (Read/Write)

[Cisco Freak]

Hello,

Can you please share the config. Also, please make sure that the new DHCP servers are cofigured with the corret DHCP scopes and they are activated also.

CF

[campbellknudson]

Here is the config.    The scopes are activated and are all good.   The DHCP servers are connected fine with a few hundred different routers.   As I mentioned, they can be pinged from these switches.   No routing issue.  

version 12.1
no service single-slot-reload-enable
no service pad
service timestamps debug datetime msec localtime
service timestamps log datetime msec localtime
service password-encryption
!
hostname PINF_DST
!
logging rate-limit console 10 except errors
enable secret 5 $1$Dv/z$b97tJf8ba
!
username supersecret password 7 00007144B18E
clock timezone CST -6
clock summer-time CDT recurring
ip subnet-zero
no ip finger
no ip domain-lookup
ip domain-name mtsallstream.com
ip name-server 142.160.xxx
ip name-server 142.160.xxx
!
no ip dhcp-client network-discovery
vpdn enable
no vpdn logging
!
vpdn-group pppoe
 request-dialin
  protocol pppoe
!
!
!
!
interface Ethernet0
 ip address 142.160.152.113 255.255.255.240
 ip helper-address 142.160.153.102
 no ip route-cache
 no ip mroute-cache
!
interface ATM0
 mtu 1400
 no ip address
 no atm ilmi-keepalive
 bundle-enable
 dsl operating-mode auto
 hold-queue 224 in
!
interface ATM0.1 point-to-point
 pvc 0/35
  protocol pppoe
 pppoe-client dial-pool-number 1
 !
!

interface Dialer1
 mtu 1400
 ip address 142.160.250.234 255.255.255.0
 encapsulation ppp
 no ip route-cache
 no ip mroute-cache
 dialer pool 1
 ppp authentication chap callin
 ppp chap hostname pinef_dist@mtssoho.vpn.mts.net
 ppp chap password 7 010B5056035A555A23
 hold-queue 224 in
!
ip classless
ip route 0.0.0.0 0.0.0.0 Dialer1
no ip http server
!
logging 10.xxx
logging 10.xxx
access-list 10 permit 142.xxx
access-list 10 permit 142xxx
access-list 10 permit 142.xxx
access-list 10 permit 142.xxx
access-list 10 permit 142.xxx
access-list 10 deny   any
snmp-server community mtswlr0 RO
snmp-server community mtswlrw0 RW
snmp-server contact ITSM Network 204-941-4904
snmp-server chassis-id Pine Falls
snmp-server host 10.45xxxx iTN3Ttr4p5
banner motd ^C

!
line con 0
 exec-timeout 120 0
 login local
 transport input none
 stopbits 1
line vty 0 4
 exec-timeout 0 0
 login local
!
scheduler max-task-time 5000
sntp server 142.xxx
sntp server 142.xxx
sntp server 142.xxx
sntp server 142.xxx
end

[Cisco Freak]

You are running DHCP helper on Etho interface whic is configured with the ip address 142.160.152.113/28.

Do you have a DHC scope matching the subnet 142.160.152.112/28 in the DHCP server?

CF

[campbellknudson]

yes, scope is there.  correct gateway.

[Cisco Freak]

Can you try to check if the DHCP server is getting DHCP discover packet from the router.

CF

[paul driver]

Helllo

just to confirm routing to this new dhcp scope is on the same server and is via the same interface as the old dhcp.server ?

It not via the dialer interface?

Res

paul

[glen.grant]

   Where is the 160.153 network and how is it connected to this box ? 

[campbellknudson]

interface Ethernet0
 ip address 142.160.152.113 255.255.255.240
 ip helper-address 142.160.153.102
 no ip route-cache
 no ip mroute-cache

that is the old dhcp server that we had to revert back to.   This router can get an address from there, but the new dhcp server (although pingable from the router) will not provide an IP address for users on the router.