Two ISP's one cisco router

Posted on 2012-09-22
Last Modified: 2012-10-04

I have a small off where we have a 2811 cisco router. We have one connection to an MPLS to the Datacenter where VoIP and other services are ran. We also have another connection off this router to a Sonicwall that is directly connected to a DSL provider. I am wanting to setup where the Sonicwall/DSL is the primary internet connection and if fails goes to the MPLS. The MPLS we have BGP and static routes for.

SonicWall to Router IP:
Router to MPLS:

We currently just use the MPLS but with VoIP and Data going accross is killing are bandwidth.
Question by:chris_npion
    LVL 9

    Expert Comment

    by:Benjamin MOREAU
    If I understand what you want to do...

    Connect your MPLS router to a second WAN port (configure for example the X3 port on WAN zone).

    Configure NLB on your Sonicwall with "Basic Active/passive Failover". Configure your DSL connexion as "primary". I suggest you to configure a probe to check if the DSL link is up (for example, ping and if it fails, switch too the backup connexion (MPLS router)).

    You can read this doc for more information :

    Author Comment

    The way it is setup on the Cisco router is

    Router serial0/0 ----> mpls
    Router fa0/0 ----> sonicwall
    LVL 8

    Expert Comment

    For this type of scenario, I use a low cost WAN aggregator/Load that will allow you to control, load balance, throttle, and/or direct Internet traffic from multiple carriers.  The WAN appliances (PowerLink) I purchased from a company called Ecessa (aka Astrocom before the company rebranded).  I have had these appliances for about four years (although I recently upgraded) and they work great.  I prefer these over Radware and F5 from a cost and features/functionality perspective.
    LVL 9

    Expert Comment

    by:Benjamin MOREAU
    Sonicwall can load balance your traffic, but you have to install your Sonicwall as your gateway. Then, connect your 2 access (MPLS & DSL) behind your Sonicwall.

    You don't need F5 or other load balancing system....
    LVL 3

    Accepted Solution

    Cisco Router

    Serial0/0 --->MPLS
    FA0/0 ---> Sonicwall

    Create static routes:

    You should know your VoIP/Other Services ranges:

    ip route x.x.x.x x.x.x.x Serial0/0 (this should be VoIP range other services)
    ip route x.x.x.x x.x.x.x Serial0/0 (add as many as you need to send towards MPLS)

    ip route Fa0/0 (Add a default route point to SonicFW (Rest of the of the internet routes))

    Now you have only VoIP/other services going through MPLS and Internet through Sonic.

    LVL 3

    Expert Comment

    Sorry didn't notice you need Backup plan for internet:

    Addition to the above fail over for Internet routes:

    Step1 : Configuring SLA process

        R1(config)#ip sla 1


        R1(config-ip-sla-echo)#frequency 5 (Means, every 5 second send icmp-echo packet to the ip This can by any reliable IP on internet)


    Step2: Scheduling SLA process

        R1(config)#ip sla schedule 1 start-time now life forever (Means, start the sla process now and don’t end)

    Note: we can check the process using the following command

        R1#show ip sla statistics

    Step3: Create a track object to track the change. It is used to inform the router about the current condition

        R1(config)#track 10 rtr 1 reachability (this will inform the router if any reachability problem occurs. rtr is the old name of IP SLA)


    Step4: Create two DEFAULTroute two both ISPs with some tweaks

        R1(config)#ip route fastEthernet 0/0 track 10

        R1(config)#ip route Serial0/0 2

    Now router will select ISP1 as primary path because of administrative distance is lower. If the link to ISP1 is down, then router automatically switch the connection to ISP2



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