cisco 891 interface routing

[galaxy1983]

Hi all..

I'm having some trouble configuring porting between interfaces.

Here is my situation.

I have a Cisco 891 router. What I need is to create 3 interfaces with the next IPs:

1.  Port FastEthernet 8 - 20.40.1.1 - with a modem connected directly to it - 20.40.1.2

2.  Port GigabitEthernet 0 - 193.2.5.100 - connected to a switch - LAN

3.  Ports FastEthernet 0 and 1 for two VOIP phones - 190.168.5.2 and 190.168.5.3 - will be switchported to VLAN 10 - 190.168.5.1

I can send ping from a PC (193.2.5.1) to the modem interface (20.40.1.1) but not to the modem itself (20.40.1.2).

I played days with configurations and tried a lot of variation of ip routing and access-lists with no success.

Basically I need to comunicate freely betwin all the devices.

There are a lot of forums providing solutions to a same problems but they seems not working with the 891 router.

Can anyone show me the way, assuming I have a factory resetted router?

Edit:

Here my configurations:

interface FastEthernet0

no ip address

!

interface FastEthernet1

no ip address

!

interface FastEthernet2

no ip address

!

interface FastEthernet3

no ip address

!

interface FastEthernet4

no ip address

!

interface FastEthernet5

no ip address

!

interface FastEthernet6

no ip address

!

interface FastEthernet7

no ip address

!

interface FastEthernet8

ip address 20.40.1.1 255.255.255.0

duplex auto

speed auto

!

interface GigabitEthernet0

ip address 193.2.5.100 255.255.255.0

duplex auto

speed auto

!

interface Vlan1

no ip address

!

interface Async1

no ip address

encapsulation slip

!

ip forward-protocol nd

!

no ip http server

no ip http secure-server

!

control-plane

!

mgcp profile default

!

line con 0

line 1

modem InOut

stopbits 1

speed 115200

flowcontrol hardware

line aux 0

line vty 0 4

login

transport input all

!

end

Message was edited by: galaxy1983

[paolo bevilacqua]

You need to set an address to VLAN 1.

[galaxy1983]

Why would I need to do that?

[paolo bevilacqua]

galaxy1983 wrote:
Why would I need to do that? 

Because it's needed.

[chad patterson]

What's needed is an explanation.

[SOcchiogrosso]

Does the modem have a route back to your network?


Sent from Cisco Technical Support Android App

[galaxy1983]

Yes

[Sam Smiley]

I am not familiar with the 891 that you show here; however it is common practice on the lower end routers that all of the faX ports are switchports, not L3 ports. As mentioned before you will need to add a VLAN1 address; this will assign a network to FastErthernet0 - 8. If by some chance this router does support L3 ports you will be able to issue a "no switchport" command on the interface to turn it into a L3 port prior to assigning the IP address.

These routers are designed for two destinct networks, gi0 (WAN) and VLAN1 (LAN). You can not add a 3rd routed interface to them. In order for the is work you would need to move to a modular router.

Cheers,

Sam

[Alex Pfeil]

  Port GigabitEthernet 0 - 193.2.5.100 - connected to a switch - LAN

Did you account for 193.2.5.100 being a public IP address? You should use private IP addresses for local LAN.

Please mark helpful posts.

[Alex Pfeil]

You need to configure NAT on the outside and inside interfaces. You can then use your public IP address and port-address translation out to the internet.

outside interface command

ip nat outside

inside interface command

ip nat inside

Create an ACL to match traffic.

access-list 1 permit any

Associate the ACL to the NAT

ip nat inside source list 1 interface "interface" overload

In you configuration above, fastethernet 8 is the port.

You would then need to have a default static route out to the internet.

ip route 0.0.0.0 0.0.0.0 20.40.1.2

Please mark helpful posts.