cancel
Showing results for 
Search instead for 
Did you mean: 
cancel

Multihoming Failover Configuration

vicky.dhas
Beginner
Beginner

Hi Friends,

Need you help in suggesting best options to achieve failover in Multihoming scenario as given in the pic.

Scenario is Single CPE - 2 Service provider .SP1 should be primary for both Internet and MPLS .service should fall back on SP2 incase primary failure.

No Load sharing is required in both cases.

thanks in advance for your help as usual.

thanks

V

9 REPLIES 9

Jerry Ye
Cisco Employee
Cisco Employee

Without knowing other info such is what routing protocol, I can only suggest you to do floating static

ip route 0.0.0.0 0.0.0.0 x.x.x.x 250

HTH,

jerry

Floatin static route is not an option here as last mile is ethernet.Moreover I would like to know how to achieve this with the help of BGP

thanks

Okay, you can try floating static with IPSLA (track).

When you said BGP, are both ISP going to peer with you via BGP and give you a default route?

BGP will load share unevenly based on BGP metrics.  If you want to force traffic over a single link while the other link is in a standby mode that can also be done.  BGP is very powerful in route-filtering as well.

### CE1

router bgp 65001
no auto-summary
bgp log neighbor-changes
no syncro
neighbor 1.1.1.1 remote-as 65000
neighbor 2.2.2.2 remote-as 65000
### Add network statements as needed.
### These will be advertised to the SP.
### You can also redistribute from an IGP
### Keep in mind any network statements
### must already exit in the route table.
network 192.168.1.0 mask 255.255.255.0
exit


Chris

Hi Vicky

There are a number of way to do this:

  • You could get ISP1 to send you full Internet routes and ISP 2 to send you default only.
  • You could get both ISP to send a default only and use local preference
  • You could get both ISP to send full Internet routes and use local preference
  • Assuming you want to do either of the last two you would need to run BGP. The simplest way to prefer one ISP over the other is use the local preference attribute.I MO

    Your config would look something like this:

    Router bgp 65535

    neighbor x.x.x.x remote-as 100

    neighbor x.x.x.x route-map ISP1-Primary in

    neighbor y.y.y.y remote-as 200

    !

    route-map ISP1-Primary permit 10

         set local-preference 200

    Routes from ISP1 would be treated as more preferable than routes from ISP2 as the local-preference attribute is checked first (from the most used attributes) before AS path length and MED.

    Assuming you have taken an MPLS service from both ISPs and that the connections are over a 802.1Q trunk and the CPE has multiple VRF you can still use the above config only this time include the route maps within the bgp address-families.

    Rgds

    James