10-01-2013 08:39 PM - edited 03-04-2019 09:12 PM
I'm trying something EXTREMELY simple. ISP-->Modem-->Cisco 2851 Router-->Cisco 3560 Switch-->end-user devices.
As of now I can browse to the internet IF configured as such: ISP-->Modem-->Wifi Router-->end user devices.....BUT I cannot browse if using the desired configuration above.
I have taken the liberty of troubleshooting and I've attached my configurations (I've x'd out a few IP's for confidentiality - these are the publicly routable IP's that are specific to my ISP where I live).
From my router I can reach the internet - but from my switch and end user devices I'm not getting out. When I connect up my WIFI router between the modem and the lab router (2851 listed above) I can remotely manage my router in my house but I cannot get out to the internet. I've watched youtube tutorials, reviewed my old CCNA/CCNP books, I know many people have successfully used their lab devices to do this before.....but at the risk of asking a silly question, WHAT AM I DOING WRONG????
One things worthy of note: when I turn on "debug ip routing" I get this message across the screen periodically:
RT: NET-RED 0.0.0.0/0
My default static route and gateway of last resort has been configured.
LAN-wise I'm good, but WAN connectivity for the switch and end-user devices is just not there. I'm out of ideas at this point.
Can someone please help - or just poor cold water on me and find my silly mistake because I've been at this for a while and I'm outta gas.
Attached is my config files and troubleshooting steps. BTW...I've rebooted the modem, write-erased the switch and router countless times, taken off ip-source-routing, ip cef.....not that that should matter here, but I've tried this multiple ways.
Eric
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ALSO......I've tried setting up "ip nat inside" on all my sub-interfaces AND I've tried to just get rid of NAT all together.
I'm completely out of ideas. See configuration attached.
10-01-2013 10:51 PM
Eric,
You do have to have ip nat inside configured in your subinterfaces.
Let's narow this down a bit. Have (at least) the following configured:
interface GigabitEthernet0/0
Ip address dhcp
ip nat outside
no shutdown
interface GigabitEthernet0/1
no ip address
no shutdown
interface GigabitEthernet0/1.16
encapsulation dot1Q 16
ip address 192.168.15.1 255.255.255.0
ip nat inside
ip nat inside source list 1 interface GigabitEthernet0/0 overload
access-list 1 permit 192.168.16.0 0.0.0.255
ip route 0.0.0.0 0.0.0.0 dhcp
Try:
Router# ping 8.8.8.8
Assuming you get a successful reply, please try this:
Router# ping 8.8.8.8 source 192.168.16.1
Do you get a reply?
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