Configuring Cisco router 4451 for Internet Access

[mm5451]

I am trying to get my cisco router 4451 to route to my ISP, but have been unsuccessful. Here is what i have.

ge0/0/1

192.168.1.129 255.255.255.128

ge0/0/2

192.168.1.1 255.255.255.0

ISP Static Address

IP Address 50.78.70.245

50.78.70.252

Gateway 50.78.70.246

Need to have both ge networks to route to the ISP for internet access. Have tried using IP Route 0.0.0.0 0.0.0.0 of both ge networks but with no success, I have even taken an additional ge port and configured it with my ISP static info, but again unable to connect to the internet. I am also unable to ping any of the ISP addresses, from either of the ge networks, but can ping both ge networks.

[mm5451]

This is what i received from my ISP

CPE IP-1 50.78.70.244/30

CPE gateway - 1 50.78.70.246

CPE subnet mask -1 255.255.255.252

CPE subnet mask -2 75.75.75.75

CPE subnet mask -3 75.75.76.76

Static IP address 50.78.70.245

[vb10]

Please, configure as everything it was before and change ACL 1: 

ACL is NOT CORRECT. It WILL NOT work with such ACL, regardless what IP addresses you configure.

access-list 1 permit 192.168.1.0 mathes only ONE ip address - host 192.168.1.0. Your computer has IP address 192.168.1.5. 

Change ACL to:

access-list 1 permit 192.168.1.0 0.0.0.255

There is no guaratee, that it will work, since there is possibility of other problems, but ACL should be changed anyway

interface GigabitEthernet0/0/0
description #Outside Internet#
ip address 50.78.70.245 255.255.255.252
ip nat outside
negotiation auto
!
interface GigabitEthernet0/0/1
description #Internal Network#
ip address 192.168.1.1 255.255.255.128
ip nat inside
negotiation auto
!
interface GigabitEthernet0/0/2
ip address 192.168.1.129 255.255.255.128
ip nat inside
negotiation auto

ip nat inside source list 1 interface GigabitEthernet0/0/0 overload
!
no access-list 1
access-list 1 permit 192.168.1.0 0.0.0.255

!

ip route 0.0.0.0 0.0.0.0 50.78.70.246

[Richard Burts]

In an earlier post we were told that

I can ping ge0/0/0 50.78.70.245 but unable to ping 50.78.70.246 which is the gateway,

If the PC is able to ping the router public IP then the routing is correct. If the PC is not able to ping the provider address in that same subnet it is not a routing issue. One very common cause of this kind of issue is problems with address translation. I do suggest that the original poster try the suggestion about changing the acl used for nat and let us know if the behavior changes.

As for the earlier suggestion by Georg to change the static default route, given the further explanation from Georg I can agree that for this limited purpose it might be worth changing the static default route and see if that makes any difference.

HTH

Rick

[mm5451]

Made the changes you recommended, iam now able to ping both 50.78.70.245 and 50.78.70.246.

The pc i have connected to the switch with an IP address of 192.168.1.5, can also ping both ip 245 and 246

But that as far as i can go, unable to make an internet connection, verified internet is working as is connected to ge0/0/0, can ping from router both DNS server 75.75.75.75 and 75.75.76.76, but unable to ping from pc on network. Attached is the lastest router config.

[Georg Pauwen]

Post the output of 'ipconfig /all' from one of your PCs...

[Richard Burts]

The config as posted looks pretty reasonable. I would suggest removing this statement

ip route 0.0.0.0 0.0.0.0 GigabitEthernet0/0/0

Georg suggested this version of the static default route as a method of testing connectivity from the PC. You have told us that the PC is now able to ping the router outside interface and the provider connection address. So there is no need for this version of the static default route.

If the router is able to ping the DNS servers then that is an indication that your routing to the Internet is correct. And if the PC is able to ping the 246 address that would be an indication that the address and gateway of the PC are correct and probably indication that the address translation is working. The two most common problems i setting up Internet connectivity are issues with routing and with address translation. If both of these appear to be working, then why is the PC not able to ping the Internet? When you ping from the PC are you pinging by name or by remote IP address? Perhaps you can try a traceroute from the PC and post the output?

HTH

Rick

[mm5451]

issue solved, I had a dns issue i was unaware of until i did some trouble shooting.

[Georg Pauwen]

Hello,

out of curiosity, what was the issue ?

[mm5451]

i had the DNS addresses wrong, they were supposed to be 75.75.75.75 primary 75.75.76.76 secondary, I had them reversed 76.76.75.75 secondary, primary 75.75.75.76, i overlooked and didnt see it until i did the trouble shooting. 

[Richard Burts]

Thanks for the update letting us know that you have it sorted out and that the issue was misconfigured DNS.

HTH

Rick

[mm5451]

I want to expand the service to include two more routers I have them configured, i can ping Router C from Router B, but iam unable to ping Router A, or any on the IPS connections on Router A.

Ge0/0/2 on Router B is configured with IP Address 192.168.3.1 255.255.255.0 

Have attached a diagram of my layout, Advise! 

[mm5451]

attached is the config file for router B

[mm5451]

Iam able to ping from Router B to Router A the following IPs 50.78.70.245 and IP 192.68.1.1 and IP 192.168.1.10, but unable to ping my ISP Gateway of 50.78.70.246 or any other ip addresses.

[mm5451]

I removed ip route 0.0.0.0 0.0.0.0 GigabitEthernet0/0/0 as you suggested, it worked better than i expected, i was experiencing terrible latency issues but after the above all work great thanks.  

[mm5451]

I want to expand the internet service to 2 more routers, would you review the config for router b, and the network diagram i attached.