Multihoming using dual ISP connection to internet edge

[chris henderson]

i am trying to firm up the best configuration and design at the IE with dual ISP connects . 

i have DUAL IE routers and dual ISPs will connect to each router . 

Each IE router will have dual connects back into my internal FTD (where my public IPs and NAT sits )

what is the best design and configuration approach to achieve this 

(EBGP at IE)

(do i use iBGP , VSS ,HSRP between routers )

(do i use BGP internally to FTD or static ) HA A/S

your thoughts welcomed . 

regards ,

Chris Henderson 

[balaji.bandi]

Basic questions :

1. Do you like to use both the Links Active / Active ISP connections.

2. Do your provider offer any BGP or static ?

3. what kind of Switch you have between Routers and FTD 

4. how is your exiting network diagram ( or is this green Field ) ?

5. Do you have Dual FTD to cluster or Active / Standby ?

[chris henderson]

all great questions bb and denis i uploaded an example diagram for your view 

no switch between IE and FTD ( IE router had 10g sw ports)

both ISPs active / active ( i am thinking ebgp with PFR)

FTD is active standby ( i am also thinking this is where customer plublic IPs will exists and NAT)

[balaji.bandi]

FTD is active standby ( i am also thinking this is where customer plublic IPs will exists and NAT)

In the above question do you host Services which required NAT Public to Private IP to inside ?

[chris henderson]

hey yes the FTD will have the customer internal networks and NAT for external browsing as an example 

[Dennis Mink]

use your FTD's in HA configuration. with two routers in front of it; on to each ISP.  if your ISP's support bgp, then peer eBGP and advertise your public range out of both, tweak metric using AS path prepend to make one ISP more preferred over the other.  

this question is asked very often so there is plenty docco on the subject here on the forum