11-20-2008 04:00 PM - edited 03-04-2019 12:26 AM
I have a 2600 router which is link to my ISP ADSL which I get a DHCP IP from them, I have config the interface to take the DHCP from the ADSL, I have config NAT overload on the outside interface, however I am unable to access the internet from the LAN, when I try to ping the ISP DNS server from the router it works but when I try to ping ISP DNS from the LAN if fail. Can anyone tell me what step I am not doing to get access to the internet?
I am able to ping the IP address I got from the ADSL from the LAN.
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11-21-2008 05:55 AM
Hi,
I noticed a number of things in your config.
1) in the DHCP config, you need to exclude your router IP address for the pool that your router will be leasing out to its clients.
from the global config, please put the following command to exclude the first two ip address from the dhcp pool.
ip dhcp excluded-address 192.168.10.1 192.168.10.2
2) I also noticed that you are using the router as a dhcp client to your ISP. but you still have a static default route. please remove the default route and the static route also pointing to the outside interface.
1.e remove
ip route 0.0.0.0 0.0.0.0 72.252.152.1
ip route 192.168.2.0 255.255.255.0 FastEthernet0/0
regards.
11-20-2008 05:43 PM
Shane,
It doesn't sound like NAT is configured properly on your router. Please see the following example. If this does not help please post your config.
You need the nat configuration
int fa0/0
ip nat inside
int fa0/1
ip nat outside
ip nat inside source list 1 interface fa0/1 overload
access-list 1 permit x.x.x.x 0.0.0.255
replace x.x.x.x with your private IP addresses.
HTH,
Mark
11-20-2008 06:34 PM
When I am setting the default route should it be
0.0.0.0 0.0.0.0 x.x.x.x 1
x should be my ISP gateway?
I have set the nat just like u say, but looking at it should I get it to my ISP gateway?
11-20-2008 06:49 PM
Do you have a modem or a router connected to your ISP?
11-21-2008 02:58 AM
I have a router connected to my ISP
11-21-2008 03:01 AM
Shane
As Mark has suggested it would help if you could post your router config.
Jon
11-21-2008 05:40 AM
Current configuration : 1027 bytes
!
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname Router
ip subnet-zero
ip dhcp pool TEST
network 192.168.10.0 255.255.255.0
default-router 192.168.10.1
dns-server 65.183.0.76
lease 8
call rsvp-sync
interface FastEthernet0/0
ip address dhcp
ip nat outside
duplex auto
speed auto
!
interface Serial0/0
no ip address
shutdown
no fair-queue
!
interface BRI0/0
no ip address
encapsulation hdlc
shutdown
interface FastEthernet0/1
ip address 192.168.10.1 255.255.255.0
ip nat inside
duplex auto
speed auto
interface Serial0/1
no ip address
shutdown
ip nat inside source list internet interface FastEthernet0/0 overload
ip classless
ip route 0.0.0.0 0.0.0.0 72.252.152.1
ip route 192.168.2.0 255.255.255.0 FastEthernet0/0
ip http server
ip access-list standard internet
permit 192.168.0.0 0.0.255.255
!
dial-peer cor custom
line con 0
exec-timeout 0 0
line aux 0
line vty 0 4
!
end
11-21-2008 05:55 AM
Hi,
I noticed a number of things in your config.
1) in the DHCP config, you need to exclude your router IP address for the pool that your router will be leasing out to its clients.
from the global config, please put the following command to exclude the first two ip address from the dhcp pool.
ip dhcp excluded-address 192.168.10.1 192.168.10.2
2) I also noticed that you are using the router as a dhcp client to your ISP. but you still have a static default route. please remove the default route and the static route also pointing to the outside interface.
1.e remove
ip route 0.0.0.0 0.0.0.0 72.252.152.1
ip route 192.168.2.0 255.255.255.0 FastEthernet0/0
regards.
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