WAN Failover questions

I am referencing these articles:
https://help.mikrotik.com/docs/pages/viewpage.action?pageId=26476608
https://help.mikrotik.com/docs/display/ROS/Firewall+Marking#FirewallMarking-FirewallFilter


I have 3 questions:

1. Why is the following lines of script required and what does it do exactly, if left out will the solution still work?:

/ip/firewall/mangle
add chain=output connection-state=new connection-mark=no-mark action=mark-connection new-connection-mark=ISP1_conn out-interface=ether1
add chain=output connection-mark=ISP1_conn action=mark-routing new-routing-mark=to_ISP1 out-interface=ether1
add chain=output connection-state=new connection-mark=no-mark action=mark-connection new-connection-mark=ISP2_conn out-interface=ether2
add chain=output connection-mark=ISP2_conn action=mark-routing new-routing-mark=to_ISP2 out-interface=ether2

2. Can it be used with the firewall filter mentioned here: https://help.mikrotik.com/docs/display/ROS/Firewall+Marking#FirewallMarking-FirewallFilter

/ip firewall filter
add action=reject chain=forward connection-mark=other out-interface=ether1 reject-with=icmp-network-unreachable
add action=reject chain=forward connection-mark=first out-interface=ether2 reject-with=icmp-network-unreachable

Currently, I manually switch over to the backup ISP when one goes down. But most times, some customers say that the internet is still not working after I switch over to the second ISP. Sometimes it comes right when customers reboot their router. So I thought that the issue is due to the connections still being open and going via the default ISP.
So, will the above code solve this problem?

3. Will the solution still work in ROS v7?

Typically for a failover scenario
isp1 - check ping - distance=5
isp2 distance=10

So all users will go out ISP1 having a shorter distance.
If ping fails the router will use ISP2 as the route of choice, and when ISP1 is availalbe again, users will be redirected to isp1.

The best thread to read up is this one…
http://forum.mikrotik.com/t/advanced-routing-failover-without-scripting/136599/1

  1. are perfectly useless if you want only failover

  2. Nevermind

  3. Yes

  4. @anav has provided the simplest configuration needed
    But if you use NAT, the “connection-tracked” still valid until not dropped by timeout.
    Everytime gateway change, if using NAT, the connection-tracking table must be empty or,
    for example, VoIP stop working until the old connection-tracked (SIP helper or not) do not go on timeout.

speak of the de…pussycat

http://forum.mikrotik.com/t/dual-wan-failover-script-ping-command/150516/1