Failover link with 2 different ISP´s

[allanporto]

Hi,
We have 1 link with ISP(a) and 1 link with ISP(b).
All my servers was configured with ISP(a) IP range.
Now I need to set link(b) my default.
Link(a) need to work only if the link(b) failed.
I tried to make some static route, but this not work.

Example:

ISP(a) ---------------
Router -Ethernet-> | 100.0.0.2 |
100.0.0.1 | |100.0.0.5
| Router 2600 |--Ethernet---->Firewall
ISP(b) | | 100.0.0.6
Router --Serial--> | 200.0.0.2 | |
200.0.0.1 --------------- |
(DMZ) |
Email
100.0.0.9

I don´t need load balacing, I need only faileover without change my servers IP´s.

Can somebody help me?

 

[tschouten]

Use a floating default-gateway on router 2600.

ip route 0.0.0.0 0.0.0.0 200.0.0.1

ip route 0.0.0.0 0.0.0.0 100.0.0.1 250

When the first route fails the second one will take over. You can adjust the distance to be closer to the distance of the first default route.

 

[rburke]

Are you looking to run BGP? The problem is that if everything is addressed using ISP A and then that link goes down then if you aren't running BGP or some other routing protocol then no traffic will be able to get back to you. Let us know if that is what you want to do.

Burke

 

[allanporto]

Thanks All,
The flooting default-gateway don't work.
Now what is the must necessary is outbound traffic.
The inbound traffic, I'm thinking use dinamic DNS our fixe IP address for the servers, one IP of subnet (a) and one of subnet (b).
I'm looking some BGP docs, but I think for politics reason I have much difficult to make. BGP need configuration in my router and ISP router, right?

 

[allanporto]

I make some map of the network.
Look at

http://www.sennaporto.com.br/map.jpg

 

[rburke]

Yes you would need to contact your ISP and have them configure BGP in their router and you configure it in yours. Usually if you have a dedicated line (T1/E1) then all you need to do is call the ISP and add BGP service to that line. It usally can be setup within a week or so depending on the ISP and their schedule. In terms of your diagram then I would recommend BGP(although passing only default routes since you only have a 2600) since it is between 2 different ISPs.

Burke

 

[tschouten]

Sorry I only glanced at the ascii design, RBURKE is right in order to do this from one Router you are going to need to use BGP.

 

[hsh2hsh]

Won't the floating route work? I don't believe it. Perhaps you didn't add any DNS server entry related to the second ISP enviroment.

Simon Yu
CCNP

 

[allanporto]

Simon, I only create the floating route and try to access Internet using IP address of destiny server, and don't work. The strange is when the link was installed I'm put the floating route and work fine, but after 5 days the link stop.

 

[allanporto]

Sorry, wrong information. The link no stop, what stop is the routing to 0/0.

 

[hsh2hsh]

Sorry, I don't understand what you print very much. But I think the floating route works fine,since "after 5 days the link stop".

What is in your route table when you disconnect the primary link ? Is the floating route appear? Do you apply NAT? Do you set any pessive-interface? Is there any access-list apply to the interface?

Simon Yu
CCNP

 

[allanporto]

Using 1530 out of 29688 bytes
!
version 12.2
service timestamps debug uptime
service timestamps log uptime
service password-encryption
!
hostname phoenix
!
no logging console
enable secret 5
enable password 7
!
clock timezone
ip subnet-zero
!
!
ip telnet source-interface FastEthernet0/1
ip domain-name
ip name-server
!
!
!
!
interface FastEthernet0/0
description ISP(a)
ip address 100.0.0.2 255.255.255.252
duplex auto
speed auto
!
interface Serial0/0
description ISP(b)
bandwidth 512
ip address 200.0.0.2 255.255.255.252
encapsulation ppp
no fair-queue
!
interface FastEthernet0/1
description Inside
ip address 100.0.0.5 255.255.255.192
duplex auto
speed auto
!
ip classless
ip route 0.0.0.0 0.0.0.0 100.0.0.1
ip route 200.0.0.0 255.255.255.128 FastEthernet0/1
no ip http server
ip pim bidir-enable
!
!
coldstart warmstart
!
line con 0
line aux 0
line vty 0 4
password 7
login
!
!
end

 

[hsh2hsh]

Hi,allanpoto

If you change the sentence
" ip route 200.0.0.0 255.255.255.128 FastEthernet0/1"
to
" ip route 0.0.0.0 0.0.0.0 FastEthernet0/1 250 "
I think it will work.

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

It is a waste of money to hire a leased line of 512k just for backup. Why not apply ISDN dialer backup?

isdn switch-type xxxxxxxxxx

int fe0/0
backup interface dialer1
backup delay 5 60
backup load 90 5

int serial0/0
encap ppp
dialer pool-member 1

interface dialer1
ip address 200.0.0.x
encap ppp
dialer remote-name ISP(b)
dialer string 11111112222 class remote
dialer load threshold 50 either
dialer pool 1
dialer-group 1
ppp authentication chap
ppp multilink

map-class dialer remote
dialer in-band //assume you do not have bri interface
!
ip route 0.0.0.0 0.0.0.0 Dialer1 250
ip route 0.0.0.0 0.0.0.0 100.0.0.1
!
dialer-list 1 protocol ip permit

Simon Yu
CCNP