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In 1721 .....failover not working

Milan Rai
Level 1
Level 1

I have cisco 1721 router.....There are ethernet 0 and ethernet 1.....port connected to ISP A and ISP B....simaltanously ........At preset what i am facing is that when my network is working on ethernet 1 ( Secondary Link VSAT).........If i shut the ethernet port 0.......then whole network gets down?????

Why the hell i am facing this .........????

11 Replies 11

Raju Sekharan
Cisco Employee
Cisco Employee

Hi Milan

Can you explain your router configuration

Thanks

Raju

config

interface eth0

ip add 192.168.149.34 255.255.255.252

no ip redirects

no ip proxy-arp

full-duplex

crypto map mymap

interface eth1

ip add 192.168.75.225 255.255.255.252

ip route-cache flow

full-duplex

crypto map mymap

Both VPN is on QM_IDLE state.......

But.....my link is working on eth0 Link............At the same time if i shut the eth1.......my whole network goes DOWN.....

Why?????

Hi Milan,

Is there any chance of your return traffic coming back via Eth1?

When traffic is flowing normally via Eth0, an you check " show interface status on both links to see the traffic rate

Thanks

Raju

Hey rajs

Traffic if flowing on eth0......there are no any traffic no eth1.....i just checked that.......

Hi Milan,

How is the routing configured at both ends of the tunnels

When you shut the interface Eth1, What is the input and ouput rate on Eth0. Is both incrementing or just output rate?

When you try t otrace to remote side, where is it getting dropped?

Thanks

Raju

hey raju lets make it simple.........when i shut the interface eth1 then whole network goes down then how can i check out the tracert part...........And what is problem is that our primary link DSL eth 1..........is having packet loss.......problem......i think this may be the reason.....my link is not switching to eth1.............So eth0 is working............Due to this reason...i tought of shutting down the eth0 port so that traffic may pass through eth1...............

BUT WHOLE NETWORK GOES DOWN!!!!!!!!!!!!!

Hi,

When both interfaces are UP/UP is Internet working properly? Have you configured static or dynamic default routes pointing to ISPs?

Why you don't just use object tracking and put floating ip route? Or I miss something

Refer this link

https://supportforums.cisco.com/thread/2125902

Hope it will help.

Best regards,
Abzal

I have static route for both the network

ip route 192.168.75.228 255.255.255.252 192.168.75.226

ip route 192.168.149.24 255.255.255.252 192.168.149.33

Actually i just want to know about WHY eth0 is effected when shutting down the eth1................

No traffic on eth1.........

Hi Milan,

let me understand your problem description clearly.

Could you you elaborate what you mean by whole network goes down. Does it mean your reacahability to the remote side is affected? or your IPSEC tunnel goes down? or you face some other issue locally.

Thanks

Raju

hey raju.....

My whole network goes down mean my remote site completely goes down.......At that time...i couldn't reach my remote router..........There's no any effect on the HO side........

As we alll know eth0 and eth1 are two different interface.........Like above i would just like to know about is.....

WHY shutting down the eth1.......EFFECTS eth0????????????

sudan_023
Level 1
Level 1

hey milan i guess ip sla tracking will solve your problem. i am assuming that Ethernet0 is primary and Ethernet1 is secondary. If your scenario dont allow you to use dyanamic routing then you can use sla tracking with static route to determine primary and secondary link.

!

track 101 ip sla 101 reachability

!

ip sla 101

icmp-echo x.x.x.x #this may be your HO router's ip or vpn peer ip# source-interface Ethernet0

timeout 500

frequency 3

ip sla schedule 101 life forever start-time now

!

ip route 192.168.75.228 255.255.255.252 192.168.75.226 track 101

ip route 192.168.149.24 255.255.255.252 192.168.149.33

!

cheers

sudan

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