Not getting internet as well as ping

[Sihanu N]

Hi Experts,

We had re-arranged and purchased new public ips and changed with new modem.Following is the new network setup diag

I have started the configuration, but stucks at a point.

Current configurations setup and ip assigment is as follows

ISP modem/router(192.168.3.254)-->(192.168.3.1)1811W Router(192.168.2.254)-->(192.168.2.1)3550(interface vlan 10 - 10.0.1.254, interface vlan 192 - 192.168.1.254)--trunk-->2950

1)Configured 3550 as layer 3 switch and create a default route to  192.168.2.254

2) Configured 2 static routes(for 2 vlan range traffic) and one default route to 192.168.3.254

3) ip pass through is not configured yet, still the public ip is configured at the isp router

1811 static route configs

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

Ip route 0.0.0.0 0.0.0.0 192.168.3.254

Ip route 192.168.1.0 255.255.255.0 192.168.2.1

Ip route 10.0.1.0 255.255.255.0 192.168.2.1

3550 static route config

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

Ip route 0.0.0.0 0.0.0.0 192.168.2.254

Testing results

1)All  lan communications are working fine(inter vlan also), ping to all  servers from router is getting and ping to outside public ips are  getting from router,but not getting ping from switch 3550 to 192.168.3.254  and any of the public ips(internet).

Please advice what is the problem in the current configs.

Thanks and Regards,

Sihanu N

[cadet alain]

Hi,

have you configured NAT on the 1811 router for the subnet going to the 3550 ?

Regards.

Alain

[Sihanu N]

Hi Alain,

Thanks for the response to my post.

1) Since we are still able to get ping to internet public ips as well from router 1811, do we need a nat configuration in the router 1811?

Note: Router 1811 wan interface is private ip(192.168.3.1)

2) Why didn't get the ping to the inside ip(192.168.3.254) of modem from switch 18? Is any problem with my static router?

3) Do we need to configure IP Passthrough in the isp modem to complete configuration?

Please advice.

Thanks and Regards,

Sihanu N

[cadet alain · Accepted solution]

Hi,

1) if your ISP modem is only natting its LAN subnet then yes you will have to.

2) for the ping from switch to modem  to succeed, you must either NAT on th 1800 or have a static route on the modem for the switch-1800 subnet

Regards.

Alain

[Sihanu N]

Hi Alain,

Sorry for the delayed reply for the post.

Many many thanks for the support and giving exact answer to my queries.

Thanks and Regards,

Sihanu N