HSRP + routing

[huynhnam]

Hello, I want to ask 1 question,

       int loopback0 1.1.1.1

          Router 1

        /           \

       /             \

  Router 2      Router 3

          \         /

           Switch   192.168.1.0/24

               ||

             laptop

Router 1: 2 static route to network 192.168.1.0 through router 2 and router 3 ( router 2 is primary route, router 3 is backup)

Router 2 and router 3 has static route to ip loopback 1.1.1.1 of router 1

Router 2 and router 3 run hsrp and router 2 is active and router 3 standby

When ping from laptop to ip loopback 1.1.1.1 of router 1, it'll through router 2

 if the port on router 2 connect to switch down, router 3 will be the active, and the traffic from laptop to ip loopback of router 1 will through router 3 but when turning back from router 1, it still through router 2 because router 2 is primary

So laptop can't ping ip loopback of router 1

Please help

[Reza Sharifi]

Hi,

You need a connection between router-2 and 3, so when traffic returns from router-1 to router-2, router-2 can send it to router-3 and down to the switch and the PC. 

Right now since there is no connection between router-2 and 3, when the traffic gets to router-2 it will drop it because the link between router-2 and the switch is down.

HTH

[balaji.bandi]

Do you have HSRP both the side ?  - since the inside link go down, that will be no transparent to outside.

Either you need to run IP SLA with EEM script to change the route or interface down, or run some IGP to know the toplogy.

[huynhnam]

hello,

I don't want to run dynamic protocol, I want to config ip sla so when the interface of router 2 connect to sw down, router 1'll insert the route to 192.168.1.0 through router 3, I already try IP SLA  but it not success

Or when the interface of router 2 connect to sw down, the link between router 2 and router 3 also down, with that ideal I don't know how to do

[balaji.bandi]

 I already try IP SLA  but it not success

post the config which was not working, what you have tried for us to guide correctly.

Good example start here :

https://ipwithease.com/ip-sla-with-hsrp/

[MHM Cisco World]

two solution 

1- interconnect R2 - R3 

and then in R2

ip route 192.168.1.0/24 R3

in R3

ip route 192.168.1.0/24 R2

2-TRY using IP SLA in R1 toward VIP of HSRP 

in R1

ip route 192.168.1.0/24 R2 track 1<<<-for ip sla 

note:-only active router reply to VIP  ping

[huynhnam]

 I want to config ip sla so when the interface of router 2 connect to sw down, router 1'll insert the route to 192.168.1.0 through router 3, I already try IP SLA  but it not success

[MHM Cisco World]

can I see the config of IP SLA ?

hint for you 
ip sla icmp-echo <VIP of HSRP> source interface <interface connect R1-R2>

then 
ip route 

ip route 192.168.1.0/24 R2 track 1

[huynhnam]

I config like this

On router r1

Ip sla 1

icmp-echo 192.168.1.1(ip vip ) 

ip route 192.168.1.0/24 R2 track 1

ip route 192.168.1.0/24 R3 10

So in routing table of r1 , it should be R2 is next hop to 192.168.1.0 but not, it's r3

[MHM Cisco World · Accepted solution]

ip sla icmp-echo <VIP of HSRP> source interface <interface connect R1-R2>
need to add source of ping packet 

also check which one now is HSRP active router ?

[huynhnam]

Thank so much, i already config ip sla success

[David Ruess]

Hello,

Probably the simplest fix is to run a routing protocol (EIGRP, OSPF) on all 3 routers so if a link goes down then your network will reconverge to make up for the down link. You could also do IP SLA stuff or you could also put a link between the routers. If you do that you would need more static routes all around. 

Hope that helps

-David

[huynhnam]

can you tell more detail about ip sla.

Config ip sla on which router ? i think router 1 

and icmp-echo to which ip, I config icmp-echo to ip vip HSRP or ip on interface router r2 link to sw but not success