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I'm very new in networking and I'm trying to setup my network as follow

[ISP Modem/Router/Switch] + --- + {fxp0} [Linux Firewall] {fxp1} + --- + {??} [Cisco Router 1921] 
{GE 0/0} + --- + [Cisco Switch] + ... Servers
{GE 0/1} + --- + [Cisco Switch] + ... Servers

My questions are,

  1. Since I'm using both GE 0/0 and GE 0/1 ports to connect to switch, how can I connect my Linux Firewall (Port fxp1) to my Cisco Router?

  2. I know the USB and Console port are for configuration, can I use AUX port to connect my firewall (if so is it consider a right way)?

  3. Is my setup is right? if not can someone please explain to me to do the setup in right way.

Link to the picture of my router: Cisco Router 1921


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Why did you connect both router ports to your switch? – 1.618 Dec 13 '12 at 22:45
@1.618 - They are connected to two different switches. – mytempfw Dec 13 '12 at 22:48
@ 1.618 - So I should connect the Linux (fxp1) port to GE 0/0 and connect GE 0/1 to Cisco switch (Lets call it CS1) and then connect those two Cisco switches to CS1 Switch. Does this setup gives me VLAN as well? – mytempfw Dec 13 '12 at 22:55
Is my setup is right? how the heck should we know. You have told how you you think you want to possibly connect things, but you haven't told us what you actually need. Why do you think you need to connect both ports from the router to the switch? What kind of routing and VLAN setup do you require? – Zoredache Dec 13 '12 at 22:59
I recommend you read this online book to get some fundamental knowledge. Then decide what you need your network to do, then figure out how these devices need to connect to each other. – 1.618 Dec 14 '12 at 0:28

Since I'm using both GE 0/0 and GE 0/1 ports to connect to switch, how can I connect my Linux Firewall (Port fxp1) to my Cisco Router?

As far as I can see you have two choices.

  • Disconnect one of the ports from the switch and connect it to your firewall
  • Setup VLAN trucking, connect your firewall to the switch, and setup a VLAN that will have only the router and the firewall.

can I use AUX port to connect my firewall

The aux port is not Ethernet it is serial. Last time I looked it maxed out at ~115,200 bits per second. You cannect connect an Ethernet device directly to a serial port.

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on the first choice you mean router instead of switch? – mytempfw Dec 13 '12 at 22:57
Well you seem to want to have two Ethernet connections going from the router to the switch. I suggested you disconnect one of those wires from the switch, and connect it to the firewall... – Zoredache Dec 13 '12 at 23:00
Each port from the router is connected to different switch (I have two switches). So Firewall to Router (GE 0/0) and Router (GE 0/1) to Switch (Called S1). Then connect Switches S2 and S3 to S1. Does this setup gives me VLAN? – mytempfw Dec 13 '12 at 23:05
What the do you mean by does that give you VLAN? As far as I can tell that gives you a network with no actually connection to the Internet. VLANs are something you configure on the router/switch. – Zoredache Dec 13 '12 at 23:08
You are right I have to do some configuration in order to get the VLAN up and running on all Switches and Router, but my concern is connection wise, is it corrent setup for having 2 VLANs? – mytempfw Dec 13 '12 at 23:13

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