Cisco router 800 series port issue

[junaid haroon]

HI,

I have router 800 series it has 4 ehternet ports but i when input a command (sh ip interface brief) its shows me only one ehternet port.

Other portsa are faulty?? Can you help me why it shows me only one ehternet port.

Router#sh ip interface brief

Interface                  IP-Address      OK? Method Status                Protocol

ATM0                       unassigned      YES NVRAM  administratively down down

Ethernet0                  unassigned      YES NVRAM  administratively down down

[kcnajaf]

Hi Junaid,

"show ip intereface brief" will give details of all WAN/Layer 3 interface (where you can assign ip address).

The four ehternet interfaces which you are seeing on your router would be LAN interface where in you cannot assign a ip address. That would be the reason it is not showing through above command.

Hope that helps

Regards

Najaf

Please rate when applicable or helpful !!!

[junaid haroon]

so i can i come to know on which interface i can assign an IP address according to numbering its has 1,2,3,4.It shows me in command ehrternet0.

[kcnajaf]

Hi,

Yes..

Ethernet0 would be your WAN interface and 1,2,3,4 would be your LAN interfaces.

You could verify this by checking if you are able to input "ip address" ? command under the LAN interface. If it is LAN interface than you will not have option to ocnfigure the ip address under that interface.

conf terminal

int fas 1

ip add ?

Hope that helps

Regards

Najaf

Please rate when applicable or helpful !!!

[junaid haroon]

  i meant to say on which interface physically i insert a ethernet cable from router to our switch.

[kcnajaf · Accepted solution]

Hi,

Yes the connection to the switch should be through any one of the four LAN interfaces.

Hope that helps

Regards

Najaf

Please rate when applicable or helpful !!!

[junaid haroon]

Sorry i untentionally click on correct answer i have last question you mean when i set ip address on router interface ethernet 0 then i can connet it any port to switch it will work?

[kcnajaf]

Hi,

Thanks a lot for rating.

It will work...But again depending on your schnerio. For example you have /29 ip range and you assign one of the ip in this range to Ethernet 0 and connect that interface to a switch and put another device from the same ip range on to the same switch and same vlan then you will have the communication happening. There is no hard and fast rule which says only LAN interface should be connected to switch. You can have your WAN interface also connected to your switch depending on what you want to achieve.

Hope that helps

Regards

Najaf

Please rate when applicable or helpful !!!

[junaid haroon]

But at same time i cannot connect it to WAN interface and LAN because it has only one interface on which we can assign a IP.Other option is that we make a sub interface>

[kcnajaf]

Hi,

Sorry i dint get your point.If u could share your requirement then I can suggest some solution for the same

Regards
Najaf
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[junaid haroon]

I have DSL modem i want to confgure a Dialer and then connect a router to my internal LAN.And my LAN IP address is Range 192.168.2.0 255.255.255.0

In Simple Words I need one ehternet interface for WAN and One for LAN.How i achive this.

[kcnajaf]

Hi,

Not sure why you want the DSL modem to connect back to router as the modem will do the routing for you with out any router.
You can connect modem directly to the switch right?

Regards
Najaf

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[junaid haroon]

No i need a router for IPsec VPN configuration for branch and head office connectivity.Thats why i said you.

In Simple Words I need one ehternet interface for WAN and One for LAN.How i achive this.

[kcnajaf]

Hi Junaid,

I'm affriad to say that this may not work as you wanted this to be:-( Which model of 800 series router you have got?

Regards

Najaf

Please rate when applicable or helpful !!!

[junaid haroon]

I have a router 837.