Cisco 3725 Router with 16-Port EtherSwitch

Answered Question
Nov 23rd, 2008

Hi,


I have a Cisco 3725 router connected to our ISP (see diagram). It has a 16-port 10/100 Etherswitch (NM-16ESW). The f0/1 goes to a Cisco 3750 switch and our Internet connected servers are connected to the Cisco 3750 switch.


What I would like to do is to get rid of the Cisco 3750 switch and just use the 16-port Etherswitch on the Cisco 3725 router (see 2nd diagram). Is this possible?


When I connected a server to the 16-port Etherswitch and assigned a public IP to it - I can't ping it? What config do I need to do


Thanks.




Best,

Tony





Correct Answer by Giuseppe Larosa about 8 years 3 months ago

Hello Tony,

to use the 16 ports you need to replicate the C3750 configuration on the router.


This can be done.


let's suppose you have only one VLan on C3750


the change you need to do is


create the vlan as a L2 object


config t

vlan 5

name servers

exit


assign the switched ports to vlan 5


int f1/1

switchport

switchport mode access

switchport access vlan 5

no shut


int f1/2

switchport

switchport mode access

switchport access vlan 5

no shut

...


repeat for all the necessary ports


shut the internal "router" interface


int f0/1

desc ex l3 link to c3750

shut


create the L3 vlan 5 interface


int Vlan5

! put here all the config was on f0/1

! just skip commands like speed, duplex


ip address 10.2.168.1 255.255.255.0

! very important:

no shut



This should make it working


Hope to help

Giuseppe


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Correct Answer
Giuseppe Larosa Mon, 11/24/2008 - 07:59

Hello Tony,

to use the 16 ports you need to replicate the C3750 configuration on the router.


This can be done.


let's suppose you have only one VLan on C3750


the change you need to do is


create the vlan as a L2 object


config t

vlan 5

name servers

exit


assign the switched ports to vlan 5


int f1/1

switchport

switchport mode access

switchport access vlan 5

no shut


int f1/2

switchport

switchport mode access

switchport access vlan 5

no shut

...


repeat for all the necessary ports


shut the internal "router" interface


int f0/1

desc ex l3 link to c3750

shut


create the L3 vlan 5 interface


int Vlan5

! put here all the config was on f0/1

! just skip commands like speed, duplex


ip address 10.2.168.1 255.255.255.0

! very important:

no shut



This should make it working


Hope to help

Giuseppe


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