Internet Redundancy on a 6513

[luciano.carvalho]

Hello Guys,

I have the following scenario:

Two internet links from different SP using different routers an firewalls connected to a 6513. I need to use these two links as primary and secondary (the secondary will be used just if the primary fails) for just two specific machines and 6513 have to be responsible for jusing between primary and secondary link. The rest of the network have to use just the primary link.

Anyone have a suggestion about how  I can do this ?

Best Regards.

[Giuseppe Larosa]

Hello Luciano,

PBR policy based routing can give you the capability to divert traffic to secondary ISP based on source address

return traffic however it is difficult to control

all rest of traffic will use normal destination based routing and you will make the default route towards ISP1 the best one and the used one when it is alive.

Hope to help

Giuseppe

[luciano.carvalho]

Thank you for your repply Giuseppe.

But I have another question.

Waht would be the best way to track the primary default router to make that its alive and, if not, use the secondary route ?

Best Regards.

[Giuseppe Larosa]

Hello Luciano,

it depends on your setup:

if you use BGP, BGP provides it

if you use static routes at edge you should look for reliable static routing with object tracking

see

http://www.cisco.com/en/US/docs/ios/12_3/12_3x/12_3xe/feature/guide/dbackupx.html

you need to verify if it is supported on the device

also be aware that depending on IOS versions commands to be used may vary

you can use feature navigator to check this

http://www.cisco.com/go/fn

Hope to help

Giuseppe

[sanjaysk1]

hello Luciano,

It depends on which routing protocol you are using in your network.

You can easily achieve redundancy using static routing and IP SLA will be worthy tool to do it.

                 |--2.2.2.1---------Primary link -------2.2.2.2-ISP1------|
6513-SW - |                                                                       | ------ INTERNET
                 |--3.3.3.1---------Secondary link ----3.3.3.3-ISP2---- |

By using below commands, we can achieve reliable automatic failover between links.

6513(config)# ip sla 1
6513(config)# icmp-echo 2.2.2.2 source-interface fa0/0
6513(config)# timeout 1000
6513(config)# threshold 2
6513(config)# frequency 3
6513(config)# ip sla schedule 1 life forever start-time now

6513(config)# track 1 ip sla 1 reachability

6513(config)# ip route 0.0.0.0 0.0.0.0 2.2.2.2 track1
6513(config)# ip route 0.0.0.0 0.0.0.0 3.3.3.3 10 >>>>>>>> AD=10 used as backup link

Kindly let me know, if it works for you.

-Sanjay Singh

[Kishore Chennupati]

Luciano,

Since, you are saying that you have routers and firewalls in between. I am assuming that your routers peer with the ISP's.

IMHO, BGP is the best option to use here. Its a dynamic routing protocol and does everything for you. Even the configuration is also simple

When using dual homing, its recommended. It also helps you to enable some other features like load sharing, load balancing etc seamlessly.

There are tons of docuements on BGP multihoming from cisco website which should give you more insight.

I have setup simillar solutions for many customers and works beautifully.

Static configuration is not scalable , although a viable option.

HTH,

Regards

Kishore