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Layer 3 Switch, Packet tracer, Help

crazo_123
Level 1
Level 1

Hello =)

 

I am new to networking and im having trouble configuring my layer 3 switch.

I have done some research and have tried several different ways to configure the multi layer switch to produce DHCP for each VLAN.

Each VLAN must have a different subnet.

 

Any help would be much appreciated 

 

Thank you <3

6 Replies 6

Sandesh Sawant
Cisco Employee
Cisco Employee

 

 

Hi,

Yes, you need to have different subnet for each vlan.

Let us consider you are having 3 vlans 10, 20 and 30.

Vlan 10 : 192.168.10.0/24

Vlan 20 : 192.168.20.0/24

Vlan 30 : 192.168.30.0/24

This switch interface vlan is the default gateway for the respective hosts in respective vlans.

 

Configuration :

 

Configure vlan 10, 20 and 30.

!
interface Vlan10
 ip address 192.168.10.1 255.255.255.0

 no shut
!
interface Vlan20
 ip address 192.168.20.1 255.255.255.0

 no shut
!
interface Vlan30
 ip address 192.168.30.1 255.255.255.0

 no shut
!

 

!

ip dhcp excluded-address 192.168.10.1 192.168.10.10
ip dhcp excluded-address 192.168.20.1 192.168.20.10
ip dhcp excluded-address 192.168.30.1 192.168.30.10
!         
ip dhcp pool vlan10
   network 192.168.10.0 255.255.255.0
   default-router 192.168.10.1 
   lease infinite
!
ip dhcp pool vlan20
   network 192.168.20.0 255.255.255.0
   default-router 192.168.20.1 
   lease infinite
!
ip dhcp pool vlan30
   network 192.168.30.0 255.255.255.0
   default-router 192.168.30.1 
   lease infinite
!
 

There are multiple options in DHCP configuration.

Configure as per your requirement.

e.g.

Cisco-switch(config)#ip dhcp pool vlan10
Cisco-switch(dhcp-config)#?
DHCP pool configuration commands:
  accounting           Send Accounting Start/Stop messages
  address              Configure a reserved address
  bootfile             Boot file name
  class                Specify a DHCP class
  client-identifier    Client identifier
  client-name          Client name
  default-router       Default routers
  dns-server           DNS servers
  domain-name          Domain name
  exit                 Exit from DHCP pool configuration mode
  hardware-address     Client hardware address
  host                 Client IP address and mask
  import               Programatically importing DHCP option parameters
  lease                Address lease time
  netbios-name-server  NetBIOS (WINS) name servers
  netbios-node-type    NetBIOS node type
  network              Network number and mask
  next-server          Next server in boot process
  no                   Negate a command or set its defaults
  option               Raw DHCP options
  origin               Configure the origin of the pool
  relay                Function as a DHCP relay
  remember             Remember released bindings
  renew                Configure renewal policy
  reserved-only        Only allocate reserved addresses
  server               Configure the server ID option value
  subnet               Subnet allocation commands
  update               Dynamic updates
  utilization          Configure various utilization parameters
  vrf                  Associate this pool with a VRF

 

 

To check if its working fine please use command below,

 

Cisco-switch#show  ip dhcp binding 
Bindings from all pools not associated with VRF:
IP address          Client-ID/             Lease expiration        Type
            Hardware address/
            User name
!

 

Also refer the links below,

https://supportforums.cisco.com/discussion/10791041/how-configure-cisco-switch-3750-dhcp-2-vlan

http://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst3750/software/release/12-2_52_se/configuration/guide/3750scg/swipaddr.html#wp1094520

 

Hope this helps.

--

Sandesh Sawant.

 

 

.

<rate if useful >

 

 

Thanks so much for the help =D was very useful =D

 

 

Hi Crazo,

 

Thanks for the reply and the rating.

--

With best regards,

Sandesh Sawant.

 

.

LJ Gabrillo
Level 5
Level 5

Well the reason your DHCP is not working is because you do not have an equivalent LAYER3 interface for that VLAN

You only have one L3 VLAN w/c is VLAN300
To make your DHCP work make sure to create L3 interfaces for all the networks you have in your L3 switch.

#interface vlan 10
  #ip address <IP> <SM>

#interface vlan 11
  #ip address <IP> <SM>

#interface vlan 12
  #ip address <IP> <SM>
 

vice versa

Thanks so much for the help =D was very useful =D

Hey dude don't forget to mark as correct and as well rate posts that have been helpful to you :)
It closes your discussion and as well give supportforums an archive of this :D

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