Building an office network Instructions

[Achilleas]

Hi All,

I am building an office LAN and I am using a single router connected with 2 switches to connect all users. I am also using an ASA 5510 facing the outside world and connecting this office to the main office using SITE-to-SITE tunnel. Everything is ready. 

My question is: Which is the reason to use 2 of more routers in a LAN with a single subnet? In whta circumstances we use more than one router?

Thank you!

[Leo Laohoo]

My question is: Which is the reason to use 2 of more routers in a LAN with a single subnet? In w
hta circumstances we use more than one router?

You want to have two routers (one router at each end) because you want to create an encrypted link.  This is practical when you have a public WAN provider.  If you have a dark-fibre between the two sites, you can opt not to have a router between them.

[Achilleas]

Thank you for your reply,

But if I use an ASA instead (used to connect both sites over a public wan)) then I don't really need a second router, right? On each site I use a router to connect to internet but behind it is the ASA...and then switches!

I suppose I could use a socond router in the same LAN as a wifi service only..

Thank you

[Leo Laohoo · Accepted solution]

But if I use an ASA instead (used to connect both sites over a public wan)) then I don't really need a second router, right? 

Depends on how your WAN link is terminated.  ASA can't "understand", for example, Frame Relay.  So you'll need a router with appropriate frame relay sockets and cables.  

[steinmannb · Accepted solution]

I guess he's not refering to the ISP router (like you) as he said he would connect the router to the switches. But maybe I'm reading it wrong.

Anyway I agree with you: if the Internet is availiable as Ethernet (plain or PPPoE) there is no need to have an additional router in the setup. Simply connect the switches with each other and put the ASA inside interface on one of the switch ports, connect the provider router/modem to the ASA outside interface and configure your site-to-site-VPN.

[Achilleas]

Thank you both! 

Now it is more clear when to use a second router in my network! 

Thanks again for your quick responses! 

[Leo Laohoo]

Thanks for rating our posts.  

By the way, you haven't stated what your WAN link bandwidth is and what ASA model you'll be using.