两根电信宽带，在防火墙上做出链路负载均衡

请问两根电信宽带，在防火墙上如何做负载均衡，我在虚拟机上做的配置不知道是否准确，因为我配置好了之后测试始终存在问题，不断开外网的情况下，ping两个外网都正常，一旦断开其中一个外网，然后再回复正常，后面ping任意一个外网就不通了，请问这是什么问题？配置命令如下

nqa template icmp nqa

 description test

 reaction trigger per-probe

#

interface GigabitEthernet1/0

 port link-mode route

 ip address 192.168.1.2 255.255.255.0

 ip last-hop hold

 nat outbound

#

interface GigabitEthernet2/0

 port link-mode route

 ip address 122.226.245.242 255.255.255.252

 ip last-hop hold

 nat outbound

 ip route-static 0.0.0.0 0 192.168.1.1

 ip route-static 0.0.0.0 0 122.226.245.241 preference 70

loadbalance link-group jiating

 transparent enable

#

virtual-server 1 type link-ip

 virtual ip address 0.0.0.0 0

 default link-group jiating

 service enable

#

loadbalance link link1

 router ip 192.168.1.1

 link-group jiating

 probe nqa

#

loadbalance link link2

 router ip 122.226.245.241

 link-group jiating

 max-bandwidth outbound 51200 kbps

 bandwidth outbound busy-rate 90 recovery 80

 probe nqa

#

security-policy ip

 rule 0 name any

  action pass