How to setup a network with 2 ISP??

[Yong Shiuh Rong]

My company is going to subscribe Broadband from 2 ISPs. I need to draw up a network plan and diagram. How am I going to connect the office network to 2 ISPs at the same time?

What I know is I need 2 router to connect to 2 ISPs. After the routers, what device should I connect in order for the whole network to run without any hiccup? I have a couple of 3COM superstack 3 baseline switches now connecting the LAN.

Or it is not possible at all to connect 2 ISPs at the same time?

[Joaquin Gil de Vergara]

you need a load balancer in order to balance traffic across two routers... (Cisco Local Director, Radware Linkproof)

You also can set up a HSRP (Hot Standby Routing Protocol) in routers. This set up a "floating" IP address betwen them, but one acts an active router and other only works if primary router fails

[Anthony Davis]

You could easily use a cisco 2600 series for this type of connection. The 2600 router comes with removeable cards, you could use serial cards or Fastethernet cards(Usually has 4 ports to use). It depends on the type of connection your using with the ISP(CSU/DSU or ethernet connection). Connect both ISP connections to the router and subnet your office. For instance the Accounting, Billing, Executive offices are on one subnet and Mail, HR etc are another subnet or like the response above use the second ISP for load balancing, but you can do it on one router. After the router you can use your 3com or buy a cisco switch. The cisco switch will help to avoid broadcast and/or collisions. Setup VLANS for different depts if necessary. For example:


Serial 0
description ISP #1
ip address 10.1.1.1 255.255.255.252

Serial 1
description ISP #2
ip address 10.2.1.1 255.255.255.252


Fastetherent0/0
description LAN for ISP #1
ip address 192.1.1.1 255.255.254.0
ip address 192.1.2.1 255.255.254.0 secondary

Fastethernet0/1
description LAN for ISP #2
ip address 172.1.1.1 255.255.254.0
ip address 172.1.2.1 255.255.254.0 secondary


The subnets for the two Fastethernet gives you the options of furture growth with 512 hosts per interface. Or you can load balance.
Check out www.cisco.com for more information about Network Configuration.