Solved: Re: DHCP on VLANs

SamuelBarata · ‎12-09-2020

Hi, I'm trying to set up DHCP on 3 VLANs

#show ip dhcp pool

Pool vlan2 :

Utilization mark (high/low) : 100 / 0

Subnet size (first/next) : 0 / 0

Total addresses : 1022

Leased addresses : 0

Pending event : none

1 subnet is currently in the pool :

Current index      IP address range                             Leased addresses
10.2.80.1           10.2.80.1             - 10.2.83.254      0

The other dhcp pools for the other 2 vlans are set up the same way

When I run `ip dhcp` on a VPC (connected to any interface on f1/5 - f1/15 on Sw11) and I get a "Can't find dhcp server"

show ip dhcp statistics

on SwR10 does not show any DHCP requests received

What am I missing in the router configuration?

Thanks

!

!
version 12.4
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
no service dhcp
!
hostname SwR10
!
boot-start-marker
boot-end-marker
!
!
no aaa new-model
memory-size iomem 5
no ip icmp rate-limit unreachable
ip cef
!
!
no ip dhcp use class
no ip dhcp use vrf connected
no ip dhcp conflict logging
ip dhcp excluded-address 10.2.80.1 10.2.80.99
ip dhcp excluded-address 10.3.80.1 10.3.80.99
ip dhcp excluded-address 10.4.80.1 10.4.80.99
!
ip dhcp pool vlan2
   network 10.2.80.0 255.255.252.0
   default-router 10.2.80.9 
!
ip dhcp pool vlan3
   network 10.3.80.0 255.255.252.0
   default-router 10.3.80.9 
!
ip dhcp pool vlan4
   network 10.4.80.0 255.255.252.0
   default-router 10.4.80.10 
!
!
no ip domain lookup
ip auth-proxy max-nodata-conns 3
ip admission max-nodata-conns 3
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
vtp file nvram:vlan.dat

!
!
ip tcp synwait-time 5
! 
!
!
!
!
interface FastEthernet0/0
 description *** Unused for Layer2 EtherSwitch ***
 no ip address
 shutdown
 duplex auto
 speed auto
!
interface FastEthernet0/1
 description *** Unused for Layer2 EtherSwitch ***
 no ip address
 shutdown
 duplex auto
 speed auto
!
interface FastEthernet1/0
 switchport mode trunk
 duplex full
 speed 100
!
interface FastEthernet1/1
 switchport mode trunk
 duplex full
 speed 100
!
interface FastEthernet1/2
 switchport mode trunk
 duplex full
 speed 100
!
interface FastEthernet1/3
 switchport mode trunk
 duplex full
 speed 100
!
interface FastEthernet1/4
 switchport mode trunk
 duplex full
 speed 100
!
interface FastEthernet1/5
 switchport access vlan 2
 switchport mode trunk
 duplex full
 speed 100
!
interface FastEthernet1/6
 switchport access vlan 2
 switchport mode trunk
 duplex full
 speed 100
!
interface FastEthernet1/7
 switchport access vlan 2
 switchport mode trunk
 duplex full
 speed 100
!
interface FastEthernet1/8
 switchport access vlan 2
 switchport mode trunk
 duplex full
 speed 100
!
interface FastEthernet1/9
 switchport access vlan 3
 switchport mode trunk
 duplex full
 speed 100
!
interface FastEthernet1/10
 switchport access vlan 3
 switchport mode trunk
 duplex full
 speed 100
!
interface FastEthernet1/11
 switchport access vlan 3
 switchport mode trunk
 duplex full
 speed 100
!
interface FastEthernet1/12
 switchport access vlan 3
 switchport mode trunk
 duplex full
 speed 100
!
interface FastEthernet1/13
 switchport access vlan 4
 switchport mode trunk
 duplex full
 speed 100
!
interface FastEthernet1/14
 switchport access vlan 4
 switchport mode trunk
 duplex full
 speed 100
!
interface FastEthernet1/15
 switchport access vlan 4
 switchport mode trunk
 duplex full
 speed 100
!
interface Vlan1
 ip address 10.1.80.10 255.255.252.0
!
interface Vlan2
 ip address 10.2.80.10 255.255.252.0
!
interface Vlan3
 ip address 10.3.80.10 255.255.252.0
!
interface Vlan4
 ip address 10.4.80.10 255.255.252.0
!
ip forward-protocol nd
!
!
no ip http server
no ip http secure-server
!
no cdp log mismatch duplex
!
!
!
control-plane
!
!
!
!
!
!
!
!
!
banner exec 

***************************************************************
This is a normal Router with a SW module inside (NM-16ESW)
It has been preconfigured with hard coded speed and duplex

To create vlans use the command "vlan database" from exec mode
After creating all desired vlans use "exit" to apply the config

To view existing vlans use the command "show vlan-switch brief"

Warning: You are using an old IOS image for this router.
Please update the IOS to enable the "macro" command!
***************************************************************


!
line con 0
 exec-timeout 0 0
 privilege level 15
 logging synchronous
line aux 0
 exec-timeout 0 0
 privilege level 15
 logging synchronous
line vty 0 4
 login
!
!
end

!
!
!

!
version 12.4
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
no service dhcp
!
hostname Sw11
!
boot-start-marker
boot-end-marker
!
!
no aaa new-model
memory-size iomem 5
no ip routing
no ip icmp rate-limit unreachable
no ip cef
!
!
!
!
no ip domain lookup
ip auth-proxy max-nodata-conns 3
ip admission max-nodata-conns 3
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
vtp file nvram:vlan.dat

!
!
ip tcp synwait-time 5
! 
!
!
!
!
interface FastEthernet0/0
 description *** Unused for Layer2 EtherSwitch ***
 no ip address
 no ip route-cache
 shutdown
 duplex auto
 speed auto
!
interface FastEthernet0/1
 description *** Unused for Layer2 EtherSwitch ***
 no ip address
 no ip route-cache
 shutdown
 duplex auto
 speed auto
!
interface FastEthernet1/0
 switchport mode trunk
 duplex full
 speed 100
!
interface FastEthernet1/1
 switchport mode trunk
 duplex full
 speed 100
!
interface FastEthernet1/2
 switchport mode trunk
 duplex full
 speed 100
!
interface FastEthernet1/3
 switchport mode trunk
 duplex full
 speed 100
!
interface FastEthernet1/4
 switchport mode trunk
 duplex full
 speed 100
!
interface FastEthernet1/5
 switchport access vlan 2
 duplex full
 speed 100
!
interface FastEthernet1/6
 switchport access vlan 2
 duplex full
 speed 100
!
interface FastEthernet1/7
 switchport access vlan 2
 duplex full
 speed 100
!
interface FastEthernet1/8
 switchport access vlan 2
 duplex full
 speed 100
!
interface FastEthernet1/9
 switchport access vlan 3
 duplex full
 speed 100
!
interface FastEthernet1/10
 switchport access vlan 3
 duplex full
 speed 100
!
interface FastEthernet1/11
 switchport access vlan 3
 duplex full
 speed 100
!
interface FastEthernet1/12
 switchport access vlan 3
 duplex full
 speed 100
!
interface FastEthernet1/13
 switchport access vlan 4
 duplex full
 speed 100
!
interface FastEthernet1/14
 switchport access vlan 4
 duplex full
 speed 100
!
interface FastEthernet1/15
 switchport access vlan 4
 duplex full
 speed 100
!
interface Vlan1
 no ip address
 no ip route-cache
!
interface Vlan2
 no ip address
!
interface Vlan3
 no ip address
!
interface Vlan4
 no ip address
!
ip forward-protocol nd
!
!
no ip http server
no ip http secure-server
!
no cdp log mismatch duplex
!
!
!
control-plane
!
!
!
!
!
!
!
!
!
banner exec 

***************************************************************
This is a normal Router with a SW module inside (NM-16ESW)
It has been preconfigured with hard coded speed and duplex

To create vlans use the command "vlan database" from exec mode
After creating all desired vlans use "exit" to apply the config

To view existing vlans use the command "show vlan-switch brief"

Warning: You are using an old IOS image for this router.
Please update the IOS to enable the "macro" command!
***************************************************************


!
line con 0
 exec-timeout 0 0
 privilege level 15
 logging synchronous
line aux 0
 exec-timeout 0 0
 privilege level 15
 logging synchronous
line vty 0 4
 login
!
!
end

Richard Burts · ‎12-10-2020

In the config that is posted in the original post I see this

no service dhcp

which would certainly explain why DHCP is not working.

HTH

Rick

View solution in original post

SamuelBarata · ‎12-09-2020

balaji.bandi · ‎12-09-2020

what missing in the configuration ? what we need to ask you to share the config, so we can verify what is missing here.

looks like you have DHCP helper address missing here. high level, we need more information to address correctly

what are the vlan ?

what vlan working ?

what vlan not working ?

what is the address svi configured for that vlan ?

show run for all the device help us to guide correct direction.

BB

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SamuelBarata · ‎12-10-2020

updated question
the switches interfaces 5-15 are on access mode on different VLANs
and 1-5 on trunk mode

balaji.bandi · ‎12-10-2020

Not sure what VPC not getting the IP address, can you give us vpc no getting IP and what port connected.

if the device connected access port - the config should be accessport - there is no need to have Trunk config

Example config as below :

interface FastEthernet1/12
switchport mode access
 switchport access vlan 3
 duplex full
 speed 100

BB

***** Rate All Helpful Responses *****

How to Ask The Cisco Community for Help

Richard Burts · ‎12-10-2020

In the config that is posted in the original post I see this

no service dhcp

which would certainly explain why DHCP is not working.

HTH

Rick