Solved: Routing to the internet

wilsonleonardy · ‎11-07-2011

Hi, I'm new to Cisco router.

I've been asked to create a network for a hotel internet service.

I'm currently configuring Cisco 1941 (non-wireless), and I've been stuck for a while now.

So, I have 2 network

192.168.0.* (ethernet0/0) and 192.168.1.* (ethernet0/1)

i connect my modem to ethernet0/0 and the client switch to ethernet0/1

I manage to ping the modem from a client, and it's working great.

the problem is i couldn't get through the internet.

is there any configuration that i missed?

and also, is it possible to manage the bandwidth to the client?

Thanks.

cadet alain · ‎11-09-2011

Hi,

Concerning NAT hat's what I had told you before, these soho models should nat everything entering their inside interface even if the src ip is not in the same subnet as the interface.

The static default route you've got is not correct so delete it and do this:

ip route 0.0.0.0 0.0.0.0 192.168.0.1

Because when doing a static route for a multipoint interface you should specify the next-hop and not the outgoing interface

but that's what you did so your Cisco router is going to ARP for every destination he wants to reach and if the soho router is not doing proxy-arp( which he surely doesn't ) then it can't work.

Regards.

Alain

Don't forget to rate helpful posts.

View solution in original post

Jon Marshall · ‎11-14-2011

Wilson / Alain

Apologies for jumping in as i don't want to cause any confusion but i suspect after reading the thread that the issue may be, as already suggested, that the modem is only natting for it's own local subnet. Could you, as Alain has already mentioned, try adding this to your 1941 config and retest -

int gi0/0

ip nat outside

int gi0/1

ip nat inside

access-list 101 permit ip 192.168.1.0 0.0.0.255 any

ip nat inside source list 101 interface gi0/0 overload

and then retest from a PC in the 192.168.1.x network (not the router itself).

Alternatively adding a route for the 192.168.1.0/24 network to the modem pointing to 192.168.0.2 would also be an option but not sure how easy this would be to do.

Can you try the above and retest.

Jon

View solution in original post

vmiller · ‎11-07-2011

Your service provider needs to allocate a public IP address to you. at that point you perform Network address translation

to allow your clients to share the public address.

wilsonleonardy · ‎11-07-2011

I have a public IP address from my ISP.

and i have applied the DHCP service on the router.

so logically there shouldn't be any problem.

Konstantin Dunaev · ‎11-07-2011

on your router you need also a NAT, if you'd like to give the Internet access to your private IP segment. Or proxy-server, which is may be more effective in your case.

davidfield · ‎11-07-2011

you may need to post your current configs. But the general process is

- On your internal network router interfaces you have a "ip nat inside" statement

- On your public interface you have "ip nat outside"

- You then need a NAT overload statement like

"ip nat inside source list 1 interface ethernet0/0 overload"

- you need a access list for the overload statement to match your internal IP ranges against something like "

access-list 1 permit any" will do it but you may want to make it more specific

- you need a default route statement out your pulbic interface "

ip route 0.0.0.0 0.0.0.0 ethernet0/0"

Hope this helps

Dave

wilsonleonardy · ‎11-07-2011

Here is the current config of the router:

Using 1503 out of 262136 bytes

!

! Last configuration change at 23:51:33 UTC Sun Nov 6 2011

!

version 15.1

service timestamps debug datetime msec

service timestamps log datetime msec

no service password-encryption

!

hostname HotelJakarta

!

boot-start-marker

boot-end-marker

!

enable secret 5 $1$qSkP$RaAzZCkUBcimthT07A7OO0

enable password xxxxxx

!

no aaa new-model

!

no ipv6 cef

ip source-route

ip cef

!

ip dhcp excluded-address 192.168.0.1 192.168.0.10

ip dhcp excluded-address 192.168.1.1 192.168.1.5

!

ip dhcp pool Guests

network 192.168.1.0 255.255.255.0

domain-name Guests

dns-server 192.168.1.1

netbios-name-server 192.168.1.1

default-router 192.168.1.1

!

multilink bundle-name authenticated

!

crypto pki token default removal timeout 0

!

license udi pid CISCO1941/K9 sn FGL1532291Z

!

interface GigabitEthernet0/0

ip address 192.168.0.3 255.255.255.0

ip nat outside

ip virtual-reassembly in

duplex auto

speed auto

no mop enabled

!

interface GigabitEthernet0/1

ip address 192.168.1.1 255.255.255.0

ip nat inside

ip virtual-reassembly in

duplex auto

speed auto

!

ip forward-protocol nd

!

no ip http server

no ip http secure-server

!

ip nat pool Guests 192.168.0.2 192.168.0.2 netmask 255.255.255.0

ip nat inside source list 7 pool Guests

ip route 192.168.1.0 255.255.255.0 192.168.0.1

!

access-list 7 permit 192.168.1.0 0.0.0.255

!

control-plane

!

line con 0

line aux 0

line vty 0 4

password xxxxxx

login

transport input all

!

scheduler allocate 20000 1000

end

------------------------------------------------------------------------------------

I'll try the NAT statement for sure.

thank you Dave and Konstantin.

Konstantin Dunaev · ‎11-07-2011

but you don't translate your private IP into public IP in your config? or it will be done by your ISP?

and you don't hav a default gateway to your "WAN" interface.

wilsonleonardy · ‎11-07-2011

isn't it supposed to be done by the internet modem? because the modem also have router capability.

given i have to get it done on the 1941 modem, what are the configs i have to put in?

Konstantin Dunaev · ‎11-07-2011

what kind of modem do you use? can you configure it, which IP's have you configured on it?

If the modem does for you the NAT translation, that you don'need to do it on your 1941, but default gatreway on it, is still necessary , like "ip route 0.0.0.0 0.0.0.0

davidfield · ‎11-07-2011

Konstantin is correct. The config statements I listed above were if you were bridging the public IP direct onto your 1941 ethernet 0/0 interface.

Be aware though that if your external modem is doing the NAT you may have to add a static router back to your 1941 ethernet 0/0 interface for the internal 192.168.0.0/16 addresses so that your internal networks cen get traffic back in.

wilsonleonardy · ‎11-07-2011

how do i add a static router back to the 1941 ethernet0/0?

wilsonleonardy · ‎11-07-2011

the LAN ip address for the modem is 192.168.0.1, therefore I set my ethernet0/0 ip address to 192.168.0.2.

so i should put it like: ip route 0.0.0.0 0.0.0.0 192.168.0.1

did i get it right?

davidfield · ‎11-07-2011

you need to add something like 192.168.0.0 255.255.255.0 send to 192.168.0.2

davidfield · ‎11-07-2011

On the modem that is. this sends all traffic coming in from the public modem to your 1941 router to send onto your internal networks.

"you need to add something like 192.168.0.0 255.255.255.0 send to 192.168.0.2"

davidfield · ‎11-07-2011

having trouble typing. Should be:

something like 192.168.0.0 255.255.0.0 send to 192.168.0.2