A few hardware network question

Cisco and Microsoft announced a partnership that will allow them to share technology and integrate security features on Cisco's networking gear and Microsoft's server and desktop products.

Complete News Here: http://news.zdnet.com/2100-1009_22-5412415.html

I was about to buy a new switch for my network at work but this news got me thinking it might be useful for me to buy a router, Cisco probably for NAC/NAP technology.. Right now, my network is just a mess of cable plug everywhere (Like a spaghetti) so I want to start from scratch. I have (All Ethernet)

Undisclosed Company Firewall
3Com: 24 Ports Giga Switch (#1)
3Com: 6 Port Giga Switch (#2)
3Com: 24 Port 100Mg Switch (#3)
3Com: 24 Port 100Mg Switch (#4)
10 Servers and a bunch of PC.

I was planning to use my Giga 24 Port Switch (#1) as a central hub in a star topology. All the PC would connect to one of the other three 3Com Switch (#2, #3 or #4) and those switch would be connect to my 24 Ports Giga Switch (#1). My server would also be connecting to the 24 Ports Giga Switch (#1).

But right now, I'm confused so I have a few of questions on hardware networking!

1) Does Switch share the ARP or RIP databases with each others?

2) In my case, would changing my Giga 24 Port Switch (#1) by a Giga 24 Port Router would help the network speed?

3) What advantage would I have using a router as a central hub in a star topology over a switch?

4) Can you assign access rules between physical ports of a router? (Like in a Firewall between the WAN and LAN)

5) Can you assign access rules between physical ports of a switch?

Thank for your answer.

1) Does Switch share the ARP or RIP databases with each others?

It depends on the switch. For instance, take a cisco switch (managed of course).
It uses the spanning tree protocol to provide redundant paths.

http://www.cisco.com/univercd/cc/td/...an2/stpapp.htm

An unmanaged switch doesn't care about other switches. It only keeps a list of the MACs on its own ports and forwards the rest of the packets on.

At layer 2, a switch doesn't care about RIP or other routing protocols.

When you get into switching at layer 3, then you have to think about the routing protocols.

http://www.cisco.com/warp/public/cc/...o/l3c85_wp.htm

2) In my case, would changing my Giga 24 Port Switch (#1) by a Giga 24 Port Router would help the network speed?

As far as I can tell... no.

Routers decide at layer 3 (network) and route the packet(s) based on the destination network.
You only need to route when you are changing networks (subnets). If you are using the same network (same subnet), your packets won't be routed as they are not leaving the subnet.

Switches are much faster as they only look at the MAC (layer 2) and forward based on the MAC table. Based on how you describe your layout, there isn't really a need to change networks (subnets). Unless you are doing it for security. (VLANs)

You will need a router if you decide to setup VLANs (which will increase your security by keeping departments separated.) eg. Accounting can't reach the HR segment and vice versa.

3) What advantage would I have using a router as a central hub in a star topology over a switch?

If you are not using VLANs, then none.
They will do nothing for you, as there will nothing to route.

4) Can you assign access rules between physical ports of a router? (Like in a Firewall between the WAN and LAN)

Yes, you can create access lists telling which traffic is allowed to go where.
It is just like a firewall. You are going to permit or deny traffic on each interface based on source and destination.

5) Can you assign access rules between physical ports of a switch?

Yes... using VLANs.

Hope I answered you accurately. I'm not the best at explaining things. I have horrible communication skills. :( I'm also no expert on switching, so hopefully others will reply either confirming what I've said, adding to it or maybe I'm wrong all together. I've taken some cisco classes (semesters one and two of the cisco academy for CCNA) and they barely touch switching. It has more to do with routing. They cover switching in further classes... but I've not yet taken those. What I know on switching is just what I've read on my own.

Since switch can do VLAN, the only advantage of a router over a manage switch is that is can router packet over multiple subnet. Right?

I need to look into the specification of my 3Com Switch to know if they are layer 3 switches to know if they can do VLAN.

Thank a good start. Anyone want to add more info?

In order to use VLANs you will need a router to route between the VLANs.

[QUOTE] Originally posted here by SDK

But right now, I'm confused so I have a few of questions on hardware networking!

First of all you have to keep one thing in your mind the switches that you have currently works on layer 2 and router works on layer 3, so everything that has concern with layer 2 will be shared or rather relate with the switches.


2) In my case, would changing my Giga 24 Port Switch (#1) by a Giga 24 Port Router would help the network speed?

First thing that i understand from your point is that you want to enhance the speed of the network. Is this the case why you want to use the router or you want to use its functionality i mean routing between those of your switches. You can use this router to route data between switches.

But heres what i recommended you there is a technology called MPLS , if you can get a router whice support this technology then its highly recommended that you go for it. What benefits you get will be 1. High speed. Reason this bring layer 2 switching to layer 3 routing means routers will be acting as a switch you can get the complete detail about this by searching google. By the way i am writing a tutorial on it , soon i will complete it.


3) What advantage would I have using a router as a central hub in a star topology over a switch?

Here you are just increasing the overhaed on the network, why everytime you send a data from on network to other will pass through this router, so it had to check the packet network addresss, on the other hand its also gonna give you an advantage if you dont use a router in your case then when a packet from one network wants to goto other network it will be broadcasted.

4) Can you assign access rules between physical ports of a router? (Like in a Firewall between the WAN and LAN)

As replied by phishphreek80 yes you can implement rules which we called Access Control List (ACL), also refer as Packet Filltering Rules. Well they are quite easy to implement but you must be very careful while implementation cause poor implementation of rules lead to two main problems: -

1. Bottle Neck.
2. Can effect the speed.


5) Can you assign access rules between physical ports of a switch?

For me access rules in switches is something not clear i mean wht u really means can u elobrate that further. anyways first thing you can assign IP to your switch ports which will help in managing the switch too. Also you can create VLANS this will help in securing your network internally, but for doing this you need a backbone switch very powerful i mean high speed. You can also use router to route between these VLANS but its not mandatory or necessary that without router you cannt get the feature of VLAN, as i said you can use a switch at backbone too.

I'll start looking at my switch speficiation when I get some time.. (I'll probably work on that Saturday because I'm too busy)