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Two different isp's for a single interface


           Can anyone help me out with this

Can we assign two public IP's for a single router interface & if yes then both the IP address should be in working condition parallely.  If yes give me a description and set of commands in a step by step order

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Two different isp's for a single interface

I am not sure what you are really trying to accomplish and getting it to really work is almost certainly more complex than just how to get public IP addresses from different ISPs onto a single interface. But you asked a direct question has possible answers. Here are two alternatives which accomplish getting two ISP addresses onto a single interface.

interface fastethernet0/1

ip address

ip address 255,255,255,252 secondary


Interface fastethernet 0/1.1

   encapsulation dot1q 10

   In address

Interface fastethenet 0/1.2

   encapsulation dot1q 20

   In address



New Member

Re: Two different isp's for a single interface

In this configuartion

using secondary

We one link gets down that other IP comes into active

*But what i need is both the Ip's should be in active state and both should load balance and share the network traffic and both the public Ip's should be made available for internal network which is series.

and IN THE SECOND scenerio  you were explaining about inter vlan routing but if the configure trunk ports then . It is not possible to connect both the Interfaces(i.e, physical and virtual interface ) to a single private network which is

New Member

Re: Two different isp's for a single interface

Hi Prafful,

1.Got 1 question what is a reason to connect both IPS to single interface due to shortage of ports on router and can you also mention the model of router.

2.If you want both IPS to be in active state and do load  balancing you might need to run BGP but you might need to consider your current hardware.

3.For physical connectivity of your ISP you will require minimum layer 2 switch on which your ISP will terminate and single up link to your router ; this is were Richard Second configuration will apply.



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