Hello
I have a 1721 router.
It has 1 internal fastethernet and 1 T-1 card that connects to my ISP over a private T-1 connection.
Everything works ok.
I'm attempting to get another fastethernet or ethernet card to connect to a DSL provider.
How can I get the router to failover (and possibly load balance?) over the 2 links? so that if link A fails, link B would activate and vice versa?
Here's the config:
Current configuration : 858 bytes
!
version 12.3
service timestamps debug datetime msec
service timestamps log datetime msec
service password-encryption
!
hostname eggster34
!
enable secret 5 xxx
!
ip subnet-zero
!
!
!
!
!
!
!
interface FastEthernet0
description LAN interface
ip address x.x.x.x 255.255.255.240 (public ip)
speed auto
!
interface Serial0
description WAN connection
ip address 172.31.0.10 255.255.255.252
!
ip classless
ip route 0.0.0.0 0.0.0.0 172.31.0.9 <-- my ISPs router.
no ip http server
!
!
line con 0
password 7 xxx
login
line aux 0
line vty 0 4
password 7 xxx
login
!
no scheduler allocate
!
end
If you were to NAT on the 1721, you could create two pools of addresses to NAT behind (one pool for the current public block and another pool for the block of addresses from the second ISP). Depending on which interface traffic will be routed out will determine which address to NAT behind. This method would provide load balancing and redundancy.