Question

[billbmcse]

Newbie here...I have a Dlink router/switch/wireless device connected to my

Cable modem. I recently purchased a Cisco 871 that I'd like to practice on and was thinking of connecting it to my

DLink device to simulate a WAN connection and have 2 different networks.

How do I connect the devices though? Neither has a serial connection, only ethernet ports. Is this not doable?

[kyukim · Accepted solution]

Hi,

You can connect as below.

cable modem -----DLINK internal sw port ----------F4 871 F0~F3 --- PC

F4 on 871 is WAN link.

Connect F4 on 871 to DLINK router's internal network sw port.

On 871,

conf t

int f4

ip add dhcp

ip nat outside

int vla 1

ip add 10.x.x.x xxxx

ip nat inside

ip nat inside source list 1 int f4 over

access-list 1 permit any

Above config is very simple config.

871 got private DHCP address from DLINK as WAN IP then it will NAT again to 871's private address.

KK.

[billbmcse]

So does the WAN port (F4) on the 871 plug into any ethernet port on the DLink?

[kyukim]

Yes, connect F4 of 871 into DLINKS internal switch ports.

Most of home routers has one WAN port (ethernet port) and 4 ports of internal ports(switch module ports).

871 is small but it can use all recent 12.4 12.4T IOS versions so that you can test all IOS commands.

Hope my answer helped you.

KK.

[Reza Sharifi]

Hi Bill,

If you want to practice, the best way to do is to get a couple older routers ie 2600, 3600 on Ebay and practice with them.  You can't really do much with your cable modem and an 871.  Theses routers on Ebay go for less then a couple of hundreds dollars.  You can even buy 2500s for about $50 each, but they are very old and come only with 10mb interfaces.

HTH

Reza

[billbmcse]

Hi. I do understand that is the best way to practice and I do have a couple of 2500s to practice on. However, that really wasn

't the question. Not trying to be rude but the 2500s are old and I don't want to put them into real use at home.

They are fine for practicing commands and such but I'm trying to work through a problem with the 871.

[paolo bevilacqua]

You have been told above how to do it.