Routing to the internet

[wilsonleonardy]

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.

[Konstantin Dunaev]

Hi Wilson,

have you tried the advice with a laptop?

[cadet alain]

Hi,

Can you post screenshots from the routing on the modem/router

Alain.

[wilsonleonardy]

[Konstantin Dunaev]

you could self see that the next hop for your 192.168.x.x point to interface "ppp_xxx" which is not really LAN as it should point to. This interface seems to be your WAN interface on the modem.

[Kishore Chennupati]

Hi Wilson,

Just to add my 2 cents here. I will just run the basic packet flow through with you so that you get an idea about routing as that seems to be the problem here

1. When you send a packet to internet say 4.2.2.2 from your PC(192.168.1.20), you send it to the router which has 192.168.1.1 as the default GW. Now, make sure that your PC's have this GW otherwise nothing will work.

2. The router would see its routing table and see that 4.2.2.2 is not present and wil forward it to the modem as it has a default route  to 192.168.0.1 on the router assuming that you can ping 192.168.0.1 from your router

3. The modem does NAT and sends it to the Internet and now when the packet returns it comes to the modem which again does the NAT stuff and sees that the packet should go to 192.168.1.20. Now does your modem have a route to this network via the right next-hop/exit-interface?? your screenshot says NO as Konstantin has rightly pointed out.

4. You need to have a static route pointing to the correct outgoing interface on the modem which should be a Fasteth/gigeth whatever ethernet interface it is that connects to the router.

Please correct that and see if it works.

HTH

Kishore

[wilsonleonardy]

1. I tried pinging and turns out that it's possible to ping from Client PC (192.168.1.20) to any of the interfaces (192.168.0.2 for g0/0 and 192.168.1.1 for g0/1) and modem/router (192.168.0.1). Thus showing that basic connectivity has been established.

so the only problem here is the internet connection routing from the modem/router --> g0/0-->g0/1 --> Client PC

2. here's attached the new established static route set on the modem/router

[Konstantin Dunaev]

do you get  Internet access from your modem? Have you tested it in a simple configuration with a single PC/Laptop?

I don't think that the problem is on the Cisco router, you schould check your modem configuration.

[johnlloyd_13]

Hi Wilson,

Could you post show ip interface brief on your 1941?

Also just to cover the basics, try to use a crossover cable between the two routers.

Sent from Cisco Technical Support iPhone App

[wilsonleonardy]

Johnlloyd_13,

here's the ip interface brieff

HotelJakarta#show ip interface brief

Interface                  IP-Address      OK? Method Status                Protocol

GigabitEthernet0/0         192.168.0.2     YES NVRAM  up                    up

GigabitEthernet0/1         192.168.1.1     YES NVRAM  up                    up

NVI0                       192.168.0.2     YES unset  up                    up

HotelJakarta#

[cadet alain]

Hi,

in the screenshot from the modem/router I don't see any default route.

Could you try adding one pointing towards the ISP next-hop.

Alain

[Kishore Chennupati]

Hi Wilson,

can you please check one more thing? I am thinking the modem only NAT/PAT's the ip subnet for its LAN interface and nothing else. I mean it does a NAT/PAT only for the 192.168.0.0/24 network. But since your traffic is coming from the 192.168.1.0/24 it doesn't NAT/PAT that subnet and your packets are getting dropped. If you do a traceroute from the PC to 4.2.2.2 does it stop at 192.168.0.1 and doesnt go any further??

what i mean to say is that in Cisco routers when you configure PAT(overload) you can specify what subnet's need to be overloaded using a source list and a route-map. I am thinking on those lines..I can be corrected if I am wrong.

Can you please check how the NAT is being configured on the D-Link modem as well?

HTH

Kishore

[johnlloyd_13]

Hi,

I agree with Kishore. Looks like you need to tinker more on your D-Link router. I would suggest to check out their support site or forums for proper config and go back here to setup further your 1941.

Sent from Cisco Technical Support iPhone App

[cadet alain]

Hi Kishore,

As far as I know these soho routers NAT all ingress packets on their inside interface and don't care about the src subnet.

Regards.

Alain

[wilsonleonardy]

cadet alain, johnlloyd, kishore chennupati, konstantin dunaev,

having been going at it for around 6 hours straight, i come to a conclusion that the most probable cause for this hassling problem might either be the nat setting in the 1941 (most likely), or the ip route setting in the adsl modem (highly unlikely), also i have an aux (async) interface on the 1941 should i use that instead of the g0/0?

this is how i set up the current trial network at home, before i actually implement it on the project i'm assigned on

i was able to ping to any LOCAL ip address literally from every local ip address in that network

i was able to ping to 192.168.0.1 from g0/0, g0/1, 192.168.0.3, 192.168.1.2

i was also able to ping to any ip address using the 192.168.0.3 laptop

the 192.168.0.3 laptop was able to connect to the internet, however all the other local ip address wasnt able to establish any connections or ping to the internet or any other public ip address.

any more help is more than welcome and most appreciated,

thanks and good night

[cadet alain]

Hi,

From the ping tests results this is obviously not a static route problem on the modem/router.

So this more than likely a NAT problem or a default route problem on the 1941, what does sh ip route says?

Have you verified the 1941 has no more nat entries in its NAT table with sh ip nat translation and when pinging from the 192.168.1.0/24 network is the NAT table empty.

If so then apparently the modem/router doesn't NAT a src IP address that doesn't fall under its LAN subnet which is strange because I've mase it work like this on different soho modem/routers without problem.

In this case natting on the 1941 should remedy to the situation and so then can you do nat this way and do you ping test from a pc in this network to any public ip address.

On the interface in the 192.168.0.0/24 network : ip nat outside

On the interface in the 192.168.1.0/24 network: ip nat inside

access-list 199 permit ip 192.168.1.0 0.0.0.255 any

ip nat inside source list 199 interface gx/x where this interface is the one in the 192.168.0.0/24 network

also do this:

logging buffered 100000

access-list 198 permit icmp any any

debug ip pack detail 198

and on each interface: no ip route-cache

Then show logging and post output

Regards.

Alain.