Redundancy on WAN link

[manojkumard]

Hi,

I have two WAN routers where two different ISP were terminating on the router and both the routers were connected to the Firewall through unmanageable switch as a mediator.

Also, I have two IANA subnet (ex. 1.1.1.0/24 & 2.2.2.0/24), where 1.1.1.1 is configured on Router A & 2.2.2.1 is configured on Router B. On firewall interface1 IP is 1.1.1.2 & interface2 IP is 2.2.2.2.

Issue here is, Since, all both subet are directly connected from firewall to router, where ISP A goes down, only IP subnet on 2.2.2.0/24 is going through ISP B. but, what i required is when ISP A goes down, i need all my traffic need to routed to secondary ISP link including subnet 1.1.1.0/24 traffic.

Required your suggestion....

[Vasilii Mikhailovskii]

Hello, Manoj.

To keep both prefixes in case when singl router goes down, you need to run BGP with your ISPs and advertise your prefixes to both of them.

PS: having single firewall servicing single link is not a best practise; it' much better to run 2 firewalls in failover mode (having multiple contexts).

[manojkumard]

Thanks for your reply....

But if i run BGP also,it wont be effective.. becoz.. We have 2 default gateway (1.1.1.1 & 2.2.2.1) pointing to two different routers... So, if we ru n BGP also, If primary link goes down (1.1.1.1), incoming traffic will come via secondary link(2.2.2.1) but outgoing traffic will fall on primary link(1.1.1.1).... any suggestions...

[paul driver]

Hello.

Below is a just a default scenario but you could also incorporate this with PBR

Ip sla 1
Echo-Icmp (dest isp1) (scr wan link to isp1)
freq 5
ip sla schedule 1 start-time now life forever

track 1 rtr 1 reachability
Ip route x.x.x.x x.x.x.x ISP1 200 track 1
Ip route x.x.x.x x.x.x.x ISP2 200

Res
Paul

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