Try using the following configuration:
Note: Please make sure to configure also a udp probe to probe udp port 69, in case the application is down.
You need to configure a management policy on the interface when using a UDP probe.
That is because, when port 69 on the server will be unreachable, the server will send an ICMP unreachable.
ACE will consider a udp probe as "failed" only when it sees ICMP unreachable.
Without a management policy-map, the ICMP unreachable message will be dropped.
Also, add an ICMP probe to the rserver because udp probe will not be enough when the physical interface will be down.
That is because UDP is a connection-less protocol. To consider a UDP probe successfull, ACE need to see NO answer from the server in respose to the probe.
The ACE will not see any answer from the server when the interface is down and thus, will consider the probe as "sucessful".
With ICMP probe attached to the rserver, you also test the reachability of the server and not only the UDP port.
Here is the configuration (of course, you can chage the names of the of the objects to the name you are using if you want) :
access-list ALL line 10 extended permit ip any any
probe udp TFTP
port 69
interval 5
passdetect interval 15
probe icmp ICMP_PROBE
interval 5
passdetect interval 15
rserver host TFTP_1
ip address 10.0.0.1
probe TFTP
probe ICMP_PROBE
inservice
rserver host TFTP_2
ip address 10.0.0.2
probe TFTP
probe ICMP_PROBE
inservice
serverfarm host TFTP-SFARM
rserver TFTP_1
inservice
rserver TFTP_2
inservice
sticky ip-netmask 255.255.255.255 address source TFTP-STICKY
timeout 10
replicate sticky
serverfarm TFTP-SFARM
class-map type management match-any MANAGE
2 match protocol icmp any
class-map match-all NAT
2 match virtual-address 0.0.0.0 0.0.0.0 udp any
class-map match-all TFTP
2 match virtual-address 10.0.0.10 udp eq 69
policy-map type management first-match MANAGE
class MANAGE
permit
policy-map type loadbalance first-match ROUTE
class class-default
forward
policy-map type loadbalance first-match TFTP-POL
class class-default
sticky-serverfarm TFTP-STICKY
policy-map multi-match TFTP-MULTI
class TFTP
loadbalance vip inservice
loadbalance policy TFTP-POL
nat dynamic 1 vlan 212
class NAT
loadbalance vip inservice
loadbalance policy ROUTE
nat dynamic 2 vlan 212
interface vlan 212
ip address 10.0.0.250 255.255.255.0
no normalization
access-group input ALL
nat-pool 1 10.0.0.241 10.0.0.243 netmask 255.255.255.0 pat
nat-pool 2 10.0.0.10 10.0.0.10 netmask 255.255.255.0 pat
service-policy input TFTP-MULTI
service-policy input MANAGE
no shutdown
Let me know how it goes.
Good luck!
