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New Member

Internet link failover

Hi all,

i have following situation,

1.I have two different ISP and Two different public ip which are connected to Cisco 1841 router with Serial Intreface.

2.I have One cisco ASA 5510 which are connected to Cisco 1841 router.

3.I am looking Loadbalacing so where we need to plan NAT in Cisco ASA or Cisco 1841 Router.

Now i want to make high availablity network, if one ISP link is down second ISP will autometic should be up.

Please suggest me what we need to do??





Re: Internet link failover

Hi ,

you can use static routing with tracking feature (both on asa and router)

Here is an example using only the asa :

The same thing static route with tracking must be done on the router.


New Member

Re: Internet link failover

Hi Dan,

Thanks for reply but dear could you please give me load balancing example for Cisco 1841 router with tracking, and i have requried DMZ example because customer has factory near about 5 KM from registered office and he want to connect factory to Registered office as private link as DMZ zone connectivity??

So please suggest me what we need to do ??



Re: Internet link failover


I gues you have Ethernet backup port for redundant WAN links and load balancing on 1841 router.

Each of the Cisco 1800 Series fixed-configuration routers is equipped with either an ISDN BRI, V.92 analog modem, or Ethernet port for secondary WAN backup connection. If the primary DSL, cable, or Ethernet-access WAN is disconnected for some reason, the router will detect this failure and will fail over to the secondary backup WAN.

Please check the below link for load balance with 1841 will help you... for DMZ:

1. Take a Metro Ethernet from the factory to registered office.
2. Make connection to your LAN at registered office.
3. Create a L3 vlans (interfaces dmz1, dmz2) in your 5510 ASA
4. Create a L2 vlans (vlan 1, vlan2 these should be similar to L3 vlans which are in ASA) in your core switch at registered office
5. Assign the L2 vlans to ports where your DMZ servers connected
6. Create nat particular to your dmz zones in your ASA...DONE


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