C1841 2PC connect

[ander00212]

Hi,

How I need to configure my C1841 router if I want to connect 2pc? I added adress on port fa0/0 and 0/1, configure ip address on pc, and they wan't ping. I just can ping default gateway.

[Richard Burts]

Am I understanding correctly that each PC can ping the gateway address (and is that gateway address the interface address of the router)? 

If each PC can ping the gateway, can the gateway ping each PC?

Every time I read a post that describes difficulty in ping to a PC I suspect that the issue is about the firewall on the PC not allowing ping (which is why I ask about the gateway ping to the PC). Check each PC, turn off any firewall that might be running, and try ping again.

I you do this and ping still does not work then please post the output of these commands on the router:

show ip interface brief

show ip route

show arp

[ander00212]

Actaully I off defender and antyvirus, again reconfigured router, added RIP to 10.1.1.0 and 10.1.2.0 and both PC can ping now together.

But I've got two question. I found video on YT where someone creating topology like I, but in Packet Tracer, not physically like I, and he said we need to use cross over cable if we want connect PC to router. Is it necesarry? Now I use normal cable and everythings looks fine.

Second thing ... I've got extra 4xRJ45 (HWIC 4ESW). I want to add it to my router and connect there those PC, but i cant configure ports there. I keep getting this error: % IP addresses may not be configured on L2 links

What should I do?

[Richard Burts]

Glad to know that now the PCs do ping. I do not think that adding RIP has anything to do with whether the PCs can ping. You might want (or need) RIP if the router connected to some other networking device (another router or a laye 3 switch) and there were IP subnets in other parts of the network that you want to communicate with. But for 2 subnets connected on a single router there is not a need for RIP.

I would say that the answer about whether you need cross over cables or not is "it depends". Back in the good old days (back when I was new in networking) it did make a difference and sometimes it would need a crossover cable to connect a host device directly to a router interface. In some emulators like packet tracer it probably does make a difference - but that is due to the way that they wrote their code. With modern networking equipment many devices are capable of recognizing the connection type and adjusting automatically so that crossover may no longer be necessary.

The HWIC is basically a small switch that you add to the router. The interfaces of the HWIC act like switch ports and are members of vlan 1 by default (or of any other vlan that you might want to configure). Any PC that you connect to an HWIC interface becomes a member of the vlan that is configured for that HWIC interface. So what you need to do is to configure vlan interfaces (an SVI) for the switch port and assign IP address to the vlan interface. So if you wanted to connect a PC to the first HWIC port and to have it be in subnet 10.1.3.0 then you could configure interface vlan 1 with ip address 10.1.3.1 255.255.255.0. Going beyond that if you wanted to connect another PC to the second HWIC port and have it be in subnet 10.1.4.0 then you would need to do these steps:

- configure vlan 2 and give it a name

- configure the second HWIC port to be a member of vlan 2

- configure interface vlan 2 and give it IP address 10.1.4.1 255.255.255.0

- connect the PC to the second port and give it an IP address in 10.1.4.0.