Link to home
Start Free TrialLog in
Avatar of SPNABI
SPNABI

asked on

How to connect Cable modem thru Linksys router with Cisco routers and switch ?

I have cable internet and my provider is Northwestel Inc. My question is I am trying to setup two routers and 1 switch thrun linksys router that is connected thru cable modem. I don't have fixed IP address, using dynamic and also using DynDNS for DNS services. Please provide me the steps to connect my linksys router and cisco router and cisco swith together without having fixed IP address.
Avatar of bkepford
bkepford
Flag of United States of America image

Well your cable modem should provid you with an ethernet port. Plug that into the WAN port on the Linksys. The Linksys by default should be setup to NAT.  It should also be a default dhcp server. You need two ehternet ports in your router. Plug the Ethernet connected to one of the open ports on your linksys. Go ahead and set the port to accept a dhcp address (ip address dhcp) Then connect your second ethernet port to your first switch. Then connect your first switch to your second switch using a cross over cable.
You can address your internal network (anything attached to the 2 cisco switches) to anything you want just point them to the router as the default gateway. On your router you have to put an IP address on your inside interface (ip address 10.0.0.1 255.255.255.0) and a static route to point to the linksys router (ip route 0.0.0.0 0.0.0.0 192.168.100.1)
Avatar of SPNABI
SPNABI

ASKER

I am sorry I was out of country but the good news is I got my CCNA
and working towards CCNP.

Just for clarification I have two routers and one switch not two switches.

My modem is directly connected to WAN port of the linksys router. From the
linksys router RJ45 cable is connected to my cisco router and both cisco
router is connected through serial interface.

From the cisco router RJ45 cable is connected to my cicso catalyst switch.

LINKSYS router configuration:

Automatic configuration-DHCP
DHCP Server Setting:
Start IP address 192.168.1.100
IP Address range 192.168.1.100 to 50

NAT Enabled

Internet IP Address 216.108.184.12
Subnet Mask 255.255.255.0
Default Gateway 216.108.187.254

DNS1 208.67.222.222
DNS2 208.67.220.220
DNS3 216.108.1.1

MTU 1500
DHCP Lease Time 24 Hour



Cisco Router configuration:

Using 504 out of 32762 bytes
!
version 11.2
no service password-encryption
no service udp-small-servers
no service tcp-small-servers
!
hostname Router
!
!
no ip domain-lookup
x29 access-list 1 permit www
!
interface Ethernet0
 ip address 192.168.100.10 255.255.255.0
 ip nat outside
!
interface Ethernet1
 no ip address
 shutdown
!
interface Serial0
 ip address 10.0.0.1 255.255.255.0
 ip nat inside
!        
interface Serial1
 no ip address
 shutdown
!
no ip classless
!
!
line con 0
 exec-timeout 60 0
 password cisco
 login
line aux 0
line vty 0 4
 password cisco
 login
!
end

I haven't done the cisco switch configuration.

Somehow whatever I am doing its not working at all.

Thanks
Avatar of Les Moore
If I understand correctly:

Cable modem -> Linksys -> CiscoR1-->serial-->CiscoR2-->switch

Inside IP of Linksys = 192.168.1.1
                 |
LAN IP of R1 = 192.168.1.99 /24
Serial IP R1 = 10.0.0.1 /24
                 |
Serial IP R2 = 10.0.0.2 /24
LAN IP of R2 = 192.168.100.1 /24

Configurations:
R1interface Ethernet0
 ip address 192.168.1.99 255.255.255.0
 no ip nat outside
 no shut

interface Serial0
 ip address 10.0.0.1 255.255.255.0
 no ip nat inside
 no shut
!        
ip route 0.0.0.0 0.0.0.0 192.168.1.1
ip route 192.168.100.0 255.255.255.0 10.0.0.2
!

R2
interface Ethernet 0
 ip address 192.168.100.1 255.255.255.0
 no shut
interface Serial0
 ip address 10.0.0.2 255.255.255.0
 no shut
ip route 0.0.0.0 0.0.0.0 10.0.0.1

On the Linksys:
Add Static route for 192.168.100.0/24 - gateway LAN 192.168.1.99
Add Static route for 10.0.0.0/24 - gateway LAN 192.168.1.99

Done.

Avatar of SPNABI

ASKER

I am not sure how to setup static route in linksys router. I don't have fixed IP address, I am using DHCP based. After setting both cisco router my connection still not working thorugh cisco switch via cisco router.
ASKER CERTIFIED SOLUTION
Avatar of Les Moore
Les Moore
Flag of United States of America image

Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial