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New Member

Help me!!! 3 ISPs connect to one router

my router is connecting to 3 IPSs, (isp 1, isp 2, isp 3). is2 uses to back up isp 1. so i want all (browse web, chat, downloafiles) they go through isp1 or isp2, But if users who want to send, receive mail, vpn... they must go through isp 3.How i configure my router?

5 REPLIES
New Member

Re: Help me!!! 3 ISPs connect to one router

I think policy based routing is one option where you can choose the parameters via access lists and then define the next hop.

If you are running BGP the choosing a right policy can get it to work.

New Member

Re: Help me!!! 3 ISPs connect to one router

Please provide following details..

1) Do you have your own AS Number?

2) IP addresses you are usning belongs to which ISP?

3) do you want to use 3rd ISP as backup/or backup of 3rd isp?

Cheers

Gaurav

New Member

Re: Help me!!! 3 ISPs connect to one router

- When ISP1 disconnect, ISP2 will be active

- I want my LAN users who want to access the internet (Browsing web, chat,..) only through ISP1 or ISP2.

- And if my LAN users who want to send, receive mail, vpn… only through ISP3.

- So ISP1 or ISP2 only for users when they want to browse web, chat,..

- ISP3 only for users when they want to send, receive mail

- I have no AS

- I don’t know how to use BGP for this scenario

- How I configure my router to let it knows that if users want to browse web, chat, this router will route to ISP1 or ISP2. And if users send or receive mail, this router will route to ISP3?

- And How can I configure this router to NAT to these 3 different ISPs?

Please see my Diagram in my attached file

New Member

Re: Help me!!! 3 ISPs connect to one router

Hi,

You must be using NAT for traffic passing through ISP1 & ISP2. You also need to use NAT for ISP3 as well. For Mail and VPN specific traffic, you need to add static route in router for POP3/SMTP Mail servers IP/VPN peer IP pointing to ISP3 link.

For NAT (in ISP3 case), you need to use the IP of the ISP3 link only.Otherwise your mail/vpn traffic will be assemetric.(Out via ISP3 and In via ISP1/2)

Please let me know if its clear.

Cheers

Gaurav

New Member

Re: Help me!!! 3 ISPs connect to one router

Hi gaurav saxena

can u show me the detail about how to configure route to NAT to 3 ISP. because i can only NAT to only one ISP, if i configure to NAT more than one ISP, it is error: dynamic NAT is using.

so only one ISP can NAT at the same time

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