I'm trying to setup load balancing between two different ISP using IP SLA and PBR.
ISP1 is PPPoE (static addresses).
ISP2 uses dhcp addresses.
router 1841 (Version 12.4(25d))
simple topology :
It works great when I use static default routes for both ISP.
example : ISP1 becomes unreachable. therefore its default route is removed from the routing table using the tracking methode.
The problem is that its not a good idea to use a static default route for ISP2 because it uses dhcp and therefore the next-hop might change over time.
So I had to modify a few things in my configuration. (you can see my configuration below)
Now, when ISP2 becomes unreachable, its default route is removed from the routing table (so far so good) BUT the default route comes back a few seconds later with no reason (the track object state is still DOWN).
Any idea why I get this weird behavior ?
Tell me if you need more information.
my config :
version 12.4 service timestamps debug datetime msec service timestamps log datetime msec no service password-encryption ! hostname Router ! boot-start-marker boot-end-marker ! ! no aaa new-model ip cef ! ! ! ! no ip domain lookup ip auth-proxy max-nodata-conns 3 ip admission max-nodata-conns 3 ip sla monitor 1 // monitor ISP1 type echo protocol ipIcmpEcho 126.96.36.199 source-interface FastEthernet0/0 timeout 500 frequency 2 ip sla monitor 2 // monitor ISP2 type echo protocol ipIcmpEcho 188.8.131.52 source-interface FastEthernet0/1 timeout 500 frequency 2 ip sla monitor group schedule 1 1-2 schedule-period 4 frequency 2 start-time now life forever ! ! ! username Alexis privilege 15 secret 5 $1$UXfm$pmZh1uUxYgl1vfhBmB1YO/ ! ! ! track 1 rtr 1 delay down 6 up 6 ! track 2 rtr 2 delay down 6 up 6 ! ! ! ! interface FastEthernet0/0 // linked to ISP1 ip address 184.108.40.206 255.255.255.0 ip nat outside ip virtual-reassembly duplex auto speed auto ! interface FastEthernet0/1 // linked to ISP2 ip dhcp client route track 2 ip address dhcp ip nat outside ip virtual-reassembly duplex auto speed auto ! interface FastEthernet0/0/0 ! interface FastEthernet0/0/1 ! interface FastEthernet0/0/2 ! interface FastEthernet0/0/3 ! interface Serial0/1/0 no ip address shutdown clock rate 2000000 ! interface Serial0/1/1 no ip address shutdown clock rate 2000000 ! interface Vlan1 ip address 10.0.0.1 255.255.255.0 ip nat inside ip virtual-reassembly ip policy route-map PBR ! ip forward-protocol nd ip route 0.0.0.0 0.0.0.0 220.127.116.11 track 1 // ISP1 static default route ip route 0.0.0.0 0.0.0.0 dhcp // ISP2 dhcp default route (I needed to modify the administrative distance of the route learned through dhcp)
! ! no ip http server no ip http secure-server ip nat inside source route-map ISP1-NAT interface FastEthernet0/0 overload ip nat inside source route-map ISP2-NAT interface FastEthernet0/1 overload ! ip access-list extended HTTP permit tcp 10.0.0.0 0.0.0.255 any eq www !
access-list 1 permit 10.0.0.0 0.0.0.255 ! route-map ISP2-NAT permit 10 match ip address 1 match interface FastEthernet0/1 ! route-map PBR permit 10 match ip address HTTP set ip next-hop verify-availability 18.104.22.168 1 track 1 set ip next-hop dynamic dhcp ! route-map ISP1-NAT permit 10 match ip address 1 match interface FastEthernet0/0 ! ! ! control-plane ! ! ! line con 0 line aux 0 line vty 0 4 logging synchronous login local ! scheduler allocate 20000 1000 end
I don't see the tracking object #2 applied to the route to ISP2.
The route to ISP2 is learned through DHCP.
From my understanding, the only way to track this kind of route is to use this command in the interface configuration mode :
ip dhcp client route track 2
The following command appears in the configuration : ip route 0.0.0.0 0.0.0.0 dhcp
BUT the command I really used is : ip route 0.0.0.0 0.0.0.0 dhcp 1 ( set the administrative distance to 1. so I can load balance between several default routes (static and dhcp)). Unfortunately, there is no track option at the end of this command.
We are pleased to announce availability of Beta software for 16.6.3.
16.6.3 will be the second rebuild on the 16.6 release train targeted
towards Catalyst 9500/9400/9300/3850/3650 switching platforms. We are
looking for early feedback from customers befor...
Introduction Featured Speakers Luis Espejel is the Telecommunications
Manager of IENova, an Oil & Gas company. Currently he works with Cisco
IOS® and Cisco IOS XE platforms, and NX to some extent. He has also
worked as a Senior Engineer with the Routing P...
In this session you can learn more about Layer 3 multicast and the best
practices to identify possible threats and take security measures. It
provides an overview of basic multicast, the best security practices for
use of this technology, and recommendati...