Configuration help- VLANS gateway /DCHP and hsrp

[JahanzebA]

Hi

  i am working in the lab and stuck at one point , need suggestions on solution to this prob. LAB screenshot is attached for reference

Two switch are connected to each other via trunk link and both have Vlan 10 and Vlan 20 configured on them.

SVIs are not defined on the switch

e3/3 in another trunk link connecting to routers from each switch and routers are then connected to ISP

Currently each router is configured with sub interfaces  f0/0.10 and f0/0.20 and respective VLANS gateway IP in configured on each sub int respectively

now problem is how to configure DHCP on these routers for each respective vlans . and secondly i want to use HSRP between these two routers , R372501 being active for VLAN 10 and R372521 active for VLAN 10

i have configured but DHCP doesn't work and neither VPC is able to ping gateway

pls suggest some solution or design suggestion so that i can achieve this

[Georg Pauwen · Accepted solution]

Hello,

the below configs should work. You need to split the DHCP pools. The lower router is the Active HSRP router for Vlan20 and the Standby for Vlan10, the upper router is the reverse.

375520

ip dhcp excluded-address 1.1.1.1 1.1.1.3
ip dhcp excluded-address 1.1.1.128 1.1.1.254
ip dhcp excluded-address 2.2.2.1 2.2.2.3
ip dhcp excluded-address 2.2.2.128 2.2.2.254
!
ip dhcp pool VLAN10_LOWER_HALF
network 1.1.1.0 255.255.255.0
default-router 1.1.1.1
dns-server 8.8.8.8
!
ip dhcp pool VLAN20_LOWER_HALF
network 2.2.2.0 255.255.255.0
default-router 2.2.2.1
dns-server 8.8.8.8

interfaceFastEthernet0/0.10
description Subinterface for Vlan 10 HSRP Active
encapsulation dot1q 10
ip address 1.1.1.2 255.255.255.0
standby 10 ip 1.1.1.1
standby 10 priority 110
standby 10 preempt
!
interfaceFastEthernet0/0.20
description Subinterface for Vlan 20 HSRP Standby
encapsulation dot1q 20
ip address 2.2.2.2 255.255.255.0
standby 20 ip 2.2.2.1

375521

ip dhcp excluded-address 1.1.1.1 1.1.1.127
ip dhcp excluded-address 2.2.2.1 2.2.2.127
!
ip dhcp pool VLAN10_UPPER_HALF
network 1.1.1.0 255.255.255.0
default-router 1.1.1.1
dns-server 8.8.8.8
!
ip dhcp pool VLAN20_UPPER_HALF
network 2.2.2.0 255.255.255.0
default-router 2.2.2.1
dns-server 8.8.8.8

interfaceFastEthernet0/0.10
description Subinterface for Vlan 10 HSRP Active
encapsulation dot1q 10
ip address 1.1.1.3 255.255.255.0
standby 10 ip 1.1.1.1
!
interfaceFastEthernet0/0.20
description Subinterface for Vlan 20 HSRP Standby
encapsulation dot1q 20
ip address 2.2.2.3 255.255.255.0
standby 20 ip 2.2.2.1
standby 20 priority 110
standby 20 preempt

[JahanzebA]

Thanks Georg i appreciate your time and help. i have configured like you said, i had almost same config as well and i was just missing dhcp excluded part.

But i ran into a new prob, VPCS are not getting ip from DHCP. which i m still trying to figure out

[JahanzebA]

i just noticed, VLAN VPCS on R18 are not getting response from DHCP server . i did capture packets using wireshark and i see both routers 375521and 375520 are getting dhcp discover but no response after that and Clients says no DHCP server found

For VPCS on R9 are fine, they get ip from DHCP.

any thoughts on this

[Georg Pauwen]

Hello,

post the full running configs of both routers...

[JahanzebA]

372520#sh running-config
Building configuration...

Current configuration : 1735 bytes
!
version 12.4
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname 372520
!
boot-start-marker
boot-end-marker
!
!
no aaa new-model
memory-size iomem 5
ip cef
!
!
no ip dhcp use vrf connected
ip dhcp excluded-address 1.1.1.1 1.1.1.3
ip dhcp excluded-address 1.1.1.128 1.1.1.254
ip dhcp excluded-address 2.2.2.1 2.2.2.3
ip dhcp excluded-address 2.2.2.128 2.2.2.254
!
ip dhcp pool POOL_VLAN10
network 1.1.1.0 255.255.255.0
default-router 1.1.1.1
dns-server 8.8.8.8
!
ip dhcp pool POOL_VLAN20
network 2.2.2.0 255.255.255.0
default-router 2.2.2.1
!
!
no ip domain lookup
!
multilink bundle-name authenticated
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
archive
log config
hidekeys
!
!
!
!
!
!
!
!
interface FastEthernet0/0
no ip address
duplex auto
speed auto
!
interface FastEthernet0/0.10
description Subinterface for Vlan 20 HSRP Standby
encapsulation dot1Q 10
ip address 1.1.1.2 255.255.255.0
standby 1 ip 1.1.1.1
standby 1 priority 110
standby 10 preempt
!
interface FastEthernet0/0.20
encapsulation dot1Q 20
ip address 2.2.2.2 255.255.255.0
standby 2 ip 2.2.2.1
!
interface FastEthernet0/1
no ip address
ip nat inside
ip virtual-reassembly
shutdown
duplex auto
speed auto
!
interface FastEthernet0/1.10
!
router ospf 1
log-adjacency-changes
network 2.2.2.0 0.0.0.255 area 0
network 3.3.3.0 0.0.0.255 area 0
network 4.4.4.0 0.0.0.255 area 0
network 100.100.100.0 0.0.0.255 area 0
network 192.168.1.0 0.0.0.255 area 0
!
ip forward-protocol nd
ip route 0.0.0.0 0.0.0.0 100.100.100.10
!
!
ip http server
no ip http secure-server
!
!
!
!
!
!
!
control-plane
!
!
!
!
!
!
!
!
!
!
line con 0
line aux 0
line vty 0 4
login
!
!
end

372520#

--------------

372521#sh running-config
Building configuration...

Current configuration : 1287 bytes
!
version 12.4
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname 372521
!
boot-start-marker
boot-end-marker
!
!
no aaa new-model
memory-size iomem 5
ip cef
!
!
no ip dhcp use vrf connected
ip dhcp excluded-address 1.1.1.1 1.1.1.127
ip dhcp excluded-address 2.2.2.1 2.2.2.127
!
ip dhcp pool POOL_VLAN10
network 1.1.1.0 255.255.255.0
default-router 1.1.1.1
!
ip dhcp pool POOL_VLAN20
network 2.2.2.0 255.255.255.0
default-router 2.2.2.1
!
!
!
multilink bundle-name authenticated
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
archive
log config
hidekeys
!
!
!
!
!
!
!
!
interface FastEthernet0/0
no ip address
duplex auto
speed auto
!
interface FastEthernet0/0.10
encapsulation dot1Q 10
ip address 1.1.1.3 255.255.255.0
shutdown
standby 1 ip 1.1.1.1
!
interface FastEthernet0/0.20
description Subinterface for Vlan 20 HSRP Standby
encapsulation dot1Q 20
ip address 2.2.2.3 255.255.255.0
standby 2 ip 2.2.2.1
standby 2 priority 110
standby 2 preempt
!
interface FastEthernet0/1
no ip address
shutdown
duplex auto
speed auto
!
ip forward-protocol nd
!
!
ip http server
no ip http secure-server
!
!
!
!
!
!
!
control-plane
!
!
!
!
!
!
!
!
!
!
line con 0
line aux 0
line vty 0 4
login
!
!
end

372521#