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CANNOT CONNECT TO THE INTERNET BUT CAN PING DEFAULT GATEWAY OF ISP

ANISHPATEL
Level 1
Level 1

Hi, I cannot access the internet service from the PC to the internet. My topology seems to be isp getting internet into the g0/0 interface of the 2911 router. Then 2 2911 router connects to another 2911 router and finally, the PC gets connected to the last 2911 router.

2 Replies 2

Hello,

 

post a schematic drawing of your topology showing how your devices are connected...

pman
Spotlight

Hi,

 

If PPOE is needed then:

did you set a pppoe-client? Maybe you did not configured interface dialer?

 

- If this is the case then the default route should point to the dialer interface
(ip route 0.0.0.0 0.0.0.0 Dialer1)

- The nat should point to the dialer interface (ip nat inside source list PRIVATE-NETWORKS interface Dialer1 overload)

- Ip nat outside should be configured under interface Dialer

 

 

please see the next links:

https://ccie20728.wordpress.com/2010/10/27/configuring-pppoe/

 

https://www.cisco.com/en/US/docs/routers/access/800/850/software/configuration/guide/pppoenat.html

 

If PPOE is not needed then:
I have some assumptions, hope I'm not wrong:

on edge_router_4:

this link connecting to upstream router/switch:

interface GigabitEthernet0/0
 ip address dhcp
 ip nat outside
 ip virtual-reassembly in
 duplex auto
 speed auto
 pppoe enable group global

this link connecting to router that connected to the pc

interface GigabitEthernet0/1
 ip address 203.1.1.1 255.255.255.0
 ip nat inside
 ip virtual-reassembly in
 duplex auto
 speed auto

this route is for route traffic back to clients (172.16.1.0/24) via second router connected to pc

ip route 172.16.1.0 255.255.255.0 203.1.1.2

 

several questions:

 

1.Does edge_router_4 get ip address from dhcp server (post output of show ip int bri)?

2.Does edge_router_4 get default-route from dhcp server (interface GigabitEthernet0/0)?
(post output of show ip route command)

3. also post the output of show ip nat translations from edge_router_4.

 

When you send a ping from 172.16.1.1 to 8.8.8.8 for example you should see something like the next output:

 

edge_router_4#show ip nat translations

Pro         Inside global          Inside local          Outside local  Outside global

icmp      192.168.1.1:26      172.16.1.1:26      8.8.8.8:26      8.8.8.8:26

icmp      192.168.1.1:27      172.16.1.1:27      8.8.8.8:27      8.8.8.8:27

icmp      192.168.1.1:28      172.16.1.1:28      8.8.8.8:28      8.8.8.8:28

icmp      192.168.1.1:29      172.16.1.1:29      8.8.8.8:29      8.8.8.8:29

icmp      192.168.1.1:30      172.16.1.1:30      8.8.8.8:30      8.8.8.8:30

 

192.168.1.1 - is the DHCP ip address edge_router_4 received from DHCP server at GigabitEthernet0/0

172.16.1.1 - is the source ip address that locate at router that connected to the pc

 

at destination router (that holds the 8.8.8.8 IP address) in above example you should see something like the next output:

ICMP: echo reply sent, src 8.8.8.8, dst 192.168.1.1