Solved: about fail-over serial line.

shsong21 · ‎04-05-2007

Hi all !

I'm running Cisco 2800 series router. Now, I have one leased line with ISP and I'll connected other one with ISP soon.

So, I'd like to configuring for fail-over. If one of two leased line be down, it have to failover with normal line side. How to do I set up on router ?

I need your help. you have to remember it that i'm using two leased line on one router.

Thanks a lot.

Best Reagards.

From Seoul, S.Korea.

san_dec21 · ‎04-07-2007

you can use ip cef fuction of IOS. by using cef you have to use two static route definning the gateway of two ISP.cef loadbalance the traffic and also provide you redudancy.

View solution in original post

Danilo Dy · ‎04-05-2007

Hmmm, lease line? That means you pay for it even you don't use it.

Make more use of your investment. Since the serial lines connects to the same ISP, ask your ISP to perform BGP load sharing http://www.cisco.com/warp/public/459/40.html discuss with your ISP what is the best setup for you by looking at the example in the link (in your case, it could either be the frist diagram or the second diagram)

This will achieve redundancy + you load share traffic between two serial lines

san_dec21 · ‎04-07-2007

you can use ip cef fuction of IOS. by using cef you have to use two static route definning the gateway of two ISP.cef loadbalance the traffic and also provide you redudancy.

shsong21 · ‎04-09-2007

Thanks a lot. your answer will be many help to me.

minumathur · ‎04-07-2007

Hi

Case 1: if you want to use single link with out load sharing

I think you need to use dyanamic routing protocol like ospf , let take OSPF as example as attached diagram , you need to configure as in attchement, put the defaulte routg ( default-information originate metric command) , this will help you keep you routing table small, because you have 2800 series router, so my advice to keep your routing table small

2) case 2: if you want to load sharing link, then you need to decide either you want to load sharing 1) per packet 2) per traffic.

then you will require much configuration to do.

i thing somebody already attached cisco document for that.

i Hope this will help you out.

-Minu

ganpatspatil · ‎04-08-2007

Hi,

I think no Need to use any dynamic routing protocol as it is not a proper solution to run IGP between your network and ISP.

As you are connecting to two ISP it better to use BGP.

For failover you can use Weight...

Assign Higher weight to neighbour who is prefarable........and assign lower weight to secondary neighbour......

shsong21 · ‎04-09-2007

Thanks a lot for your all answer.

I will check up it later. I'm educated Linux system Admin on this week. haha.

Anyway, have a good day !

shsong21 · ‎04-15-2007

Hi.....I'm very very sorry but I didn't download your file. And in my case is case 2.

I want to load sharing and failover between two serial link.

How do I set up it on cisco router 2800 ?

And Can you send it to my email ?

Thanks a lot.

royalblues · ‎04-16-2007

a sampel config below

int serial 0/0

description link 1 to ISP

ip addrress x.x.x.x 255.255.255.252

int serial 0/1

description link 2 to ISP

ip addrress y.y.y.y 255.255.255.252

ip route 0.0.0.0 0.0.0.0

HTH, rate if it does

Narayan

ryanwhisler · ‎04-16-2007

I need to do Fail over. We have a T1 WAN link to the Main office which is our prefered route for all traffic destined to our internal services/servers. We also have a broadband DSL connection to which all internet destine traffic is passed. Our goal is for all traffic to be redirected to the ethernet port on which the DSL is connected if the T1 goes down. The idea being that the T1 is preferred but if it is not available all traffic would be sent to the DSL connection.

shsong21 · ‎04-16-2007

-------------------------------------------

a sampel config below

int serial 0/0

description link 1 to ISP

ip addrress x.x.x.x 255.255.255.252

int serial 0/1

description link 2 to ISP

ip addrress y.y.y.y 255.255.255.252

ip route 0.0.0.0 0.0.0.0

HTH, rate if it does

Narayan

---------------------------------------------

I also knew above configuration, BTW I have one question. In this case, is it possible failover ? As you know, the failover is other one Serial line has to live when some one Serial line is dead.

It's meaning that if one serail line is down, automatically another one has to send the data traffic to ISP.

I want it.

Thanks.....