03-11-2015 03:31 PM - edited 03-07-2019 11:03 PM
So this started suddenly after working for about a year. Clients are not getting IP addresses. We are using IP-helper for dhcp relaying. We are using 3750s across the board BUT we have an MPLS network between the client switch and the server switch. I have enabled debug and get this. It looks like it is forwarding the request but not getting anywhere afterwards. I had enabled debug IP udp but it didnt show anything.
Mar 11 16:52:19.611: DHCPD: Reload workspace interface Vlan2 tableid 0.
Mar 11 16:52:19.611: DHCPD: tableid for 172.18.2.3 on Vlan2 is 0
Mar 11 16:52:19.611: DHCPD: client's VPN is .
Mar 11 16:52:19.611: DHCPD: using received relay info.
Mar 11 16:52:19.611: DHCPD: DHCPDISCOVER received from client 013c.970e.3165.53 on interface Vlan2.
Mar 11 16:52:19.611: DHCPD: using received relay info.
Mar 11 16:52:19.611: DHCPD: Looking up binding using address 172.18.2.3
Mar 11 16:52:19.611: DHCPD: setting giaddr to 172.18.2.3.
Mar 11 16:52:19.611: DHCPD: BOOTREQUEST from 013c.970e.3165.53 forwarded to 10.33.11.21.
Sniffing 10.33.11.21 shows it is not getting discover requests form the giaddress. (it is from other vlans on other switches and is working fine there)
Rebooting the switch didnt help. dont know what else to try :/
Solved! Go to Solution.
03-11-2015 11:08 PM
If the DHCP server is not getting the request then most likely the packet was lost in transit? IS there a firewall between the client and DHCP server?
Could you please post the running config of your switch? Just remove the sensitive lines i.e. username/password/snmp/etc.
03-11-2015 05:14 PM
Conduct a packet capture on the DHCP server, check if it is receiving and replying to the request.
03-11-2015 05:30 PM
Hey Rejohn.. so sorry.. I should have included that I did that and did NOT get any traffic on the dhcp server..
The DHCP server servers several switches and vlans and wireshark shows requests from all the vlan interfaces except for the ones on the switch in question.
03-11-2015 11:08 PM
If the DHCP server is not getting the request then most likely the packet was lost in transit? IS there a firewall between the client and DHCP server?
Could you please post the running config of your switch? Just remove the sensitive lines i.e. username/password/snmp/etc.
03-12-2015 05:15 AM
Sure. There is no firewalls in the path. There is an MPLS network between the switch and the dhcp server.. .
workstation <->3750 w/DHCP Relay <->Router<->MPLS<->Router<->3750<-> DHCP
Has been working fine for over a year now. Talked to the MPLS provider and they see no issues on their hardware
errdisable recovery cause udld
errdisable recovery cause bpduguard
errdisable recovery cause security-violation
errdisable recovery cause channel-misconfig (STP)
errdisable recovery cause pagp-flap
errdisable recovery cause dtp-flap
errdisable recovery cause link-flap
errdisable recovery cause sfp-config-mismatch
errdisable recovery cause gbic-invalid
errdisable recovery cause l2ptguard
errdisable recovery cause psecure-violation
errdisable recovery cause port-mode-failure
errdisable recovery cause dhcp-rate-limit
errdisable recovery cause pppoe-ia-rate-limit
errdisable recovery cause mac-limit
errdisable recovery cause vmps
errdisable recovery cause storm-control
errdisable recovery cause inline-power
errdisable recovery cause arp-inspection
errdisable recovery cause loopback
errdisable recovery cause small-frame
!
vlan internal allocation policy ascending
!
!
class-map match-all AUTOQOS_VOIP_DATA_CLASS
match ip dscp ef
class-map match-all AUTOQOS_DEFAULT_CLASS
match access-group name AUTOQOS-ACL-DEFAULT
class-map match-all AUTOQOS_VOIP_SIGNAL_CLASS
match ip dscp cs3
!
!
policy-map AUTOQOS-SRND4-CISCOPHONE-POLICY
class AUTOQOS_VOIP_DATA_CLASS
set dscp ef
police 128000 8000 exceed-action policed-dscp-transmit
class AUTOQOS_VOIP_SIGNAL_CLASS
set dscp cs3
police 32000 8000 exceed-action policed-dscp-transmit
class AUTOQOS_DEFAULT_CLASS
set dscp default
police 10000000 8000 exceed-action policed-dscp-transmit
!
!
!
interface FastEthernet0
no ip address
no ip route-cache cef
no ip route-cache
no ip mroute-cache
shutdown
!
interface GigabitEthernet0/1
switchport access vlan 2
switchport trunk encapsulation dot1q
switchport trunk native vlan 2
switchport trunk allowed vlan 2,31
switchport mode trunk
switchport voice vlan 31
srr-queue bandwidth share 1 30 35 5
priority-queue out
mls qos trust device cisco-phone
mls qos trust cos
auto qos voip cisco-phone
storm-control broadcast level 1.00
storm-control action shutdown
spanning-tree portfast
spanning-tree bpduguard enable
spanning-tree guard root
service-policy input AUTOQOS-SRND4-CISCOPHONE-POLICY
!
! ect etc etc
interface GigabitEthernet0/47
description MPLS
switchport access vlan 102
switchport mode access
storm-control broadcast level 1.00
storm-control action shutdown
!
interface Vlan1
ip address 10.43.40.1 255.255.255.0
!
interface Vlan2
ip address 172.8.2.3 255.255.255.0
ip helper-address 10.40.11.21
ip helper-address 10.42.11.21
!
interface Vlan31
ip address 172.8.1.3 255.255.255.0
ip helper-address 10.42.11.21
ip helper-address 10.40.11.21
!
interface Vlan44
description BAY_EXT
ip address 172.29.44.2 255.255.255.0
!
interface Vlan102
description VLAN_MPLS
ip address 172.18.1.26 255.255.255.248
ip ospf hello-interval 5
!
router ospf 1
log-adjacency-changes
auto-cost reference-bandwidth 10000
redistribute static metric 1000 subnets
network 10.43.0.0 0.0.255.255 area 0
network 172.18.1.26 0.0.0.0 area 0
network 172.8.1.0 0.0.0.255 area 0
network 172.8.2.0 0.0.0.255 area 0
network 172.9.44.0 0.0.0.255 area 0
!
ip classless
ip route 0.0.0.0 0.0.0.0 172.18.1.25
ip http server
ip http secure-server
!
ip access-list extended AUTOQOS-ACL-DEFAULT
permit ip any any
06-16-2015 12:53 PM
Ok.. forgot to update this.. sorry. SO we have our hardware.. our ISP has their hardware.. but they were using another provider in that city and the OTHER ISP did a maintenance that killed our DHCP.. they fixed it and everythign worked.. thanks all!
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