How to configure router 1812 as failover or load balance internet?

[tecnoprog]

I need help to configure a router 1812 as failover,

I walk with fixed ip internet link in Fe0 (need to determine the mac) and a dynamic ip link in FE1, other ports with a single vlan dhcp 172.20.16.1

I managed to do DHCP, connect to internet, to make nat vlan.

But I could not do failover and load balance neither.

thanks for the help.

[Abzal]

Hi,

Here is simple example config

f0

ip add 1.1.1.1 255.255.255.252

ip nat outside

f1

ip add dhcp

ip nat outside

access-list 100 permit ip 172.20.16.0 0.0.0.255  //if you have other subnets on LAN you need to add ACL

ip route 0.0.0.0 0.0.0.0 1.1.1.2

ip route 0.0.0.0 0.0.0.0 f1

route-map ISP1

match ip address 100

match interface f0

route-map ISP2

match ip address 100

match interface f1

ip nat inside source route-map ISP1 interface f0 overload

ip nat inside source  route-map ISP2 interface f1 overload

Hope it will help.

Best regards,
Abzal

[tecnoprog]

Thank you,

performed the procedures mentioned and it did not work without internet access.

[Mohit Chauhan]

Anderson Carlos wrote:
I need help to configure a router 1812 as failover,
I walk with fixed ip internet link in Fe0 (need to determine the mac) and a dynamic ip link in FE1, other ports with a single vlan dhcp 172.20.16.1
I managed to do DHCP, connect to internet, to make nat vlan.
But I could not do failover and load balance neither.
thanks for the help.

Hi

I am not sure about the load balancing (unless i do some research myself) but for failover, I could think of using ip sla with default routes.

for eg,

ip route 0.0.0.0 0.0.0.0 int fe0 track 1

ip route 0.0.0.0 0.0.0.0 int fe1 200

The second default route (with AD 200) is a floating route which will only kick in if the other one fails.

you can confgigure the tracking based on the Primary ISP ip address pingable. Most of the times, the reachability to the ISP would be the reason for internet failure.

ip sla 1

icmp-echo source-interface f0

timeout 1000

threshold 2

frequency 3

ip sla schedule 1 life forever start-time now

track 1 ip sla 1 reachability

Please note that the syntax may change based on the IOS version.

Hope it helps!

Regards,

Mohit

[tecnoprog]

Thank you,

I researched and found the comados running, 'show track", monitoring the link works, however I could not share the internet.

[Mohit Chauhan]

Anderson Carlos wrote:
Thank you,
I researched and found the comados running, 'show track", monitoring the link works, however I could not share the internet.

Hi,

The solution that I suggested will not do load balancing. this will only do automatic failover when primary service fails.

Regards,

Mohit

[tecnoprog]

This configuration works if unplug the f0, f1 and assumes disconnect the f1, f0 assumes.

I'm not sure I believe in this load balance, how to use in fail over?

Remembered that monitors your code above f0.

thanks for listening.

!----------------------------------------------------------------------------------------

! WAN 0

interface F0

description Link Ajato

ip address dhcp

no shutdown

ip nat outside

ip virtual-reassembly

! WAN 1

interface F1

description Link Net

ip address dhcp

no shutdown

ip nat outside

ip virtual-reassembly

! Vlan1

interface Vlan1

description LAN Interface

ip address 172.20.16.1 255.255.255.0

ip nat inside

ip virtual-reassembly

ip tcp adjust-mss 1452

ip route 0.0.0.0 0.0.0.0 F0 track 123

access-list 110 permit ip 172.20.16.0 0.0.0.255 any

route-map fixed-nat permit 10

match ip address 110

match interface F0

route-map dhcp-nat permit 10

match ip address 110

match interface F1

ip nat inside source route-map fixed-nat interface F0 overload

ip nat inside source route-map dhcp-nat interface F1 overload

!----------------------------------------------------------------------------------------

[Mohit Chauhan]

Hi Anderson,

Honetly i did not understand your comments above. With the config that you have shown, it looks like that you are trying to merge Abzal's and mine config together. I dont think that would be a good idea.

And looking at his config template, I am not sure if you could have two default routes at the same time (never tried myself) unless someone would have done it in real scenario.

Regards,

Mohit

[cadet alain]

Hi,

of course you can have 2 default routes with the same AD and the IOS will do load-sharing per src-dst IP pair for transit traffic and per-packet for traffic generated by the device.

The problem with the latest config is that there is only one default route( what's the use of tracking a route if you haven't got a backup route to do the failover).

Regards

Alain

Don't forget to rate helpful posts.

[Mohit Chauhan]

cadet alain wrote:
Hi,
of course you can have 2 default routes with the same AD and the IOS will do load-sharing per src-dst IP pair for transit traffic and per-packet for traffic generated by the device.
The problem with the latest config is that there is only one default route( what's the use of tracking a route if you haven't got a backup route to do the failover).
Regards
Alain
Don't forget to rate helpful posts.

Well, I had suggested two default routes as per my original notes. I was expecting that there, yes otherwise there is no point of tracking the first default route.

[tecnoprog]

Good morning friends,

Would anyone have a manual on how to use ios?
So I could take a studying and not be messing with something that staff should be simple to do.

Thank you.