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Load Balance / Failover


I have Two DSL connection with Static Public-IP-address terminated on a 3640 Router and need help in configuring load-balancing and failover of links and services.

Would like to run the following services

1. Internet browsing

2. Client VPN

3. SMTP Gateway

4. Natted IP to access Server

IS there a cisco sample config for my requirement.

Currently all are working on a single DSL connection...


Re: Load Balance / Failover

You can configure IP SLA monitors to do a ping of the next-hop address of your primary DSL provider. If the ping fails, the route for the primary DSL will be yanked from the routing table and the other default route installed. This is simply a configuration for failover. Load-balancing is another beast.

Example: (may vary by IOS level)

ip sla 1

icmp-echo source-interface fastethernet0/0

ip sla schedule 1 life forever start-time now

track 1 ip sla 1 reachability

route track 1

route 254 would be the next-hop of your ISP, source-interface obviously the interface on your router where the DSL is plugged in. would be your default gateway of the primary ISP. would be the default gateway of the backup ISP.

Please rate this post if it is helpful.

New Member

Re: Load Balance / Failover

Load Balancing and backup with one Router makes sense only for Internet Browsing (1). For other duties (SMTP(3), client VPN (2), NAT (4)) you need the second Router. Should both DSL connections be active? if so, try with IP CEF (for Internet Browsing) and and routes with the same metric

New Member

Re: Load Balance / Failover

can i get sample config to load balance & failover over dsl connection....

Re: Load Balance / Failover

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