2 Switches -> 2 Routers -> 2 ISP , I need to configure auto failover

[Tariqsaudz]

Hello,

I need a help please.

I have 2 switches connected to 2 Routers and then 2 different ISPs.

     SW -----> Router(1) -----> ISP (Main)

      ||

      ||

     SW -----> Router -----> ISP (secondary)

on R1 I did this:

interface GigabitEthernet0/2
 description TO_Internet_Switch
 ip address <ip>  <MASK>
 standby 1 ip (*WHAT TO TYPE HERE ?* ).
 standby 1 priority 105
 standby 1 preempt delay minimum 20
 standby 1 track 1 decrement 10
 duplex auto
 speed auto
 media-type rj45
 negotiation auto

And

interface GigabitEthernet0/3
 description "To ISPInternet"
 ip address <IP> <MASK>
 ip flow ingress
 ip flow egress
 duplex auto
 speed auto
 media-type rj45
 negotiation auto
 

-------

While on the secondary:

interface GigabitEthernet0/2
 description TO_Internet_Switch
 ip address <IP> <MASK>
 standby 1 ip (*WHAT TO TYPE HERE ?* ).
 standby 1 preempt
 standby 1 track 2 decrement 10
 duplex auto
 speed auto
 media-type rj45
 negotiation auto

interface GigabitEthernet0/3

 description "To ISPInternet"
 ip address <IP> <MASK>
 ip flow ingress
 duplex auto
 speed auto
 media-type rj45
 negotiation auto

Firstly I need answers ? Am I correct into this ? Kindly need you assistance. Thanks :)

[Seb Rupik]

Hi there,

The IP address <(*WHAT TO TYPE HERE ?* )> needs to the same free address from the subnet that Gi0/2 interface routes.

eg:

Switch	Gi0/2	standby IP
SW1	192.168.0.253 /24	192.168.0.254 /24
SW2	192.168.0.252 /24	192.168.0.254 /24

..devices on the 192.168.0.0/24 subnet would be configured to use 192.168.0.254 as their gateway.

cheers,

Seb..

[Tariqsaudz]

Hello Sub,

It's well understood. Now I have configured the BGP on both routers as of :

router bgp 200025
 bgp log-neighbor-changes
 network <ip> mask <MASK>
 neighbor <ip> remote-as 35753
 neighbor <ip> password 7 03454F08265D2E1D1A
 neighbor <ip> soft-reconfiguration inbound
 neighbor <ip> prefix-list defualt in
 neighbor <ip> prefix-list ANNOUNCE out
 neighbor <ip> route-map ISP2-in in
 neighbor <ip> route-map ISP2-out out
 neighbor <ip> remote-as 200025
 neighbor <ip> update-source Loopback0
 neighbor <ip> next-hop-self

Am I right on this ?

Now, what are the commands that will make the auto failover work? where should be these command written? on Main router ? or both of them? what is the command.

I appreciate your help all.

[Seb Rupik · Accepted solution]

You need to configure IP SLA on both of your routers. For each one you will need to track an external IP, in the event of an ISP router failure the HSRP priority value will be decremented.

R1:

!

ip sla 1
icmp-echo 8.8.8.8 source-interface Gi0/3
timeout 5000
threshold 5000
frequency 5
ip sla schedule 1 life forever start-time now

!

R2

!

ip sla 2
icmp-echo 8.8.8.8 source-interface Gi0/3
timeout 5000
threshold 5000
frequency 5
ip sla schedule 1 life forever start-time now

!

cheers,

Seb.

[tellis002]

Also, if you are going to configure BGP to the internet routers, I would also create iBGP between your two internal routers so they can share best paths.  However, when doing so, ensure you use the "next-hop-self" command so the other router can reach the other ISP internet router if necessary.  

Router 1:

neighbor (your internal neighbor IP address) remote-as XX

neighbor (your internal neighbor IP address) remote-as XX next-hop-self

Router 2: 

neighbor (your internal neighbor IP address) remote-as XX

neighbor (your internal neighbor IP address) remote-as XX next-hop-self