Possible failover scenarios for VPNs over primary/secondary peers

Carl King · ‎09-15-2010

Hi,

We have a few clients that we establish VPNs with. The ones that use Juniper routers for VPNs want to establish a failover configuration where our VPN would dynamically route over a VPN to their secondary peer address. Their secondary peer address is on their own backup internet circuit.

They have no problem with making the failover dynamic on their side.

We have to manually change a static route to point to their secondary peer address as the gateway for their internal network before the traffic takes the secondary path. Since this client is on the other side of the world, this involves waking the oncall engineer in the middle of the night which is inherently a kludgey process.

Here's our config. I'm open to suggestions. These IP's are fictitious of course and we proxy route the public IP thru the internet firewall to enable the public loopback. Inside and outside VPN router interfaces are privately addressed.

The routes we have to change to route to their secondary peer would be these statics:

no ip route 192.168.1.0 255.255.255.0 a.a.a.a

ip route 192.168.1.0 255.255.255.0 b.b.b.b

10.1.x.0 and 10.1.y.0 are our local networks.

~~~~~

crypto map CryptoMap local-address Loopback0

crypto map CryptoMap 180 ipsec-isakmp

description VPN to client - both peers required!!!

set peer a.a.a.a

set peer b.b.b.b

set security-association lifetime kilobytes 4096

set transform-set Transform

set pfs group2

match address Client-networks

interface Loopback0

ip address 11.11.11.11 255.255.255.0

crypto map CryptoMap

ip route 192.168.1.0 255.255.255.0 a.a.a.a

ip route a.a.a.a 255.255.255.0 [firewall]

ip route b.b.b.b 255.255.255.0 [firewall]

ip access-list extended Client-networks

permit ip 10.1.x.0 0.0.0.255 192.168.1.0 0.0.0.255

permit ip 10.1.y.0 0.0.0.255 192.168.1.0 0.0.0.255

~~~~~

Thanks,

Carl King

Yudong Wu · ‎09-15-2010

You can use SLA feature on ASA.

http://www.cisco.com/en/US/docs/security/asa/asa82/command/reference/qr.html#wp1793355

Here is the example from the above link.

The following example uses an SLA operation to install a default route to the 10.1.1.1 gateway on the outside interface. The SLA operation monitors the availability of that gateway.If the SLA operation fails, then the backup route on the dmz interface is used.

hostname(config)# sla monitor 123

hostname(config-sla-monitor)# type echo protocol ipIcmpEcho 10.1.1.1 interface outside

hostname(config-sla-monitor-echo)# timeout 1000

hostname(config-sla-monitor-echo)# frequency 3

hostname(config)# sla monitor schedule 123 life forever start-time now

hostname(config)# track 1 rtr 123 reachability

hostname(config)# route outside 0.0.0.0 0.0.0.0 10.1.1.1 track 1

hostname(config)# route dmz 0.0.0.0 0.0.0.0 10.2.1.1 254

Carl King · ‎09-15-2010

I like that feature Yudong. Wish we had an ASA.

I've got a pair of Cisco 2851's.

Marcin Latosiewicz · ‎09-15-2010

Carl,

SLA was adapted to ASA from IOS ;-)

BB_967(config)#ip route 0.0.0.0 0.0.0.0 1.2.3.4 track ?
<1-500> tracked object number

http://www.cisco.com/en/US/docs/ios/12_4/ip_sla/configuration/guide/hspaecho.html#wp1027265

HTH,

Marcin

edit: added link

Carl King · ‎09-15-2010

Ah. Good. Thanks for pointing it out. I found it now.

VPN02(config)#ip sla monitor ?
<1-2147483647>          Entry Number
apm                     IP SLA Monitor APM Configuration
group                   Group configuration or Group scheduling
key-chain               Use MD5 authentication for IP SLA Monitor control
                          message
logging                 Enable logging
low-memory              Configure low water memory mark
reaction-configuration IP SLA Monitor Reaction Configuration
reaction-trigger        IP SLA Monitor trigger assignment
reset                   IP SLA Monitor Reset
responder               Enable IP SLA Monitor Responder
restart                 Restart an active entry
schedule                IP SLA Monitor Entry Scheduling
slm                     Service Level Management

Yudong Wu · ‎09-15-2010

Did you see the link which I posted is for ASA not router?

Carl King · ‎09-15-2010

Yes, I am just not familiar with the ASA and assumed the feature was platform specific.

I see now that it works on IOS.

I think I can make this work for this client.

Thanks.

Carl