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kknuckles
kknuckles
New Member
March 20, 2017
Solved

WAN Failover Best Practice - New Failover Connection

  • March 20, 2017
  • 3 replies
  • 65684 views

I have a FG200D and we are getting ready to receive a new Cradlepoint 3G/4G router for failover of the main office only. The plan is to connect it to WAN2. My question is this: Would it be better to use WAN LLB and set a sky high priority like 99 for WAN1 and 1 for WAN2, or would it be better to use two static routes and weight them accordingly?

 

I mainly want to make sure WAN2 isn't going to be used unless WAN1 is absolutely down. I don't mind a small amount of traffic for health check but we are only allotted so much data per month on the fail over service without overage charges.

 

I've seen multiple posts about this and read multiple articles, but couldn't really determine the best method from those. I've only known FortiOS 5.4, which apparently isn't the favorite for this setup since most of the failover documentation still references 5.2.

 

Opinions and thoughts welcomed and thanks in advance.

 

Kevin

Best answer by btp
That’s the main idea with Fortinet’s SD-WAN offering - path selection. We use this to use one of two fibers - and mobile backup if the sh*t hits the fan.. for many spokes.

3 replies

MikePruett
MikePruett
New Member
March 20, 2017

I, personally, would do this.

 

create a zone titled OUTSIDE

 

place primary internet provider and secondary internet provider in there.

 

Create two default routes, one to the primary and one to the secondary. Make the secondary have a slightly higher "priority" which in FortiOS just means cost.

 

Configure link health monitoring through CLI for each connection. If primary WAN fails the configured number of times then it will yank the route and use the backup line.

 

below is how to configure the link monitor

 

config system link-monitor

edit "wan1fail"

set srcintf "wan1"

set server "8.8.8.8"

set interval 3

set failtime 10

set recoverytime 10

set update-cascade-interface disable

set protocol ping

next

end

kknuckles
kknucklesAuthor
New Member
March 20, 2017

Thanks Mike!

phowardmhm
phowardmhm
New Member
May 1, 2017

I will be doing the same setup as described, any thoughts or ideas are appreciated.  Thanks, Pat

wcbenyip
wcbenyip
New Member
May 2, 2017

Sounds this is a good method for WAN load balancing... but another trouble point is, you have to configure 2 complete set of policies for each interface going thru WAN1 and WAN2. That means, once you need to modify any policy from one of your huge no. of policies, you have to do it twice... and whenever need to create a new policy, you have to duplicate it for 2 WAN port.

 

I set the WAN LB with this same method, it's really painful. Just thought does there another way to make it more precise or simple? Double no. of policies and making a complex policy screen are really not a best practice.... and it's not the normal WAN LOAD BALANCING in the market...

Maxim_Vanichkin
Maxim_Vanichkin
Visitor III
May 2, 2017

For exemple, ZyWALLs have "trunks" - 2,3,4... interfaces there (active, passive) - very easy! In your policies and routes you use only configured trunks - very convinent. Do FGs have such functionality?

fl0at0xff
fl0at0xff
New Member
May 2, 2017

Hello,

 

i'm not expert of DUAL wan but if I understand correctly, you simply want to do a WAN Failover and not a Load balancing right ? If yes, I suggest you to use only static. Here my guide lines:

[ol]
  • Configure default static route (wan1/wan2 with same distance but wan1 with lowest priority)
  • Create link-monitor using CLI for each WAN. (config sys link-monitor) (-> set update-static-route disable)
  • If you use IPSec, create your second IPSec that will use wan2. In CLI, don't forget to set the parameter "set monitor <gw_ip_wan1> that tell that this backup VPN IPSec must monitor the first one
  • Add static route for your new IPsec (IPsec tunnel 2 with same distance than primary but higher priority)
  • If you have not created a ZONE for WAN1 et WAN2, you must dupplicate all your policies/VIP for wan2
  • If you have SSL/VPN, don't forget to add wan2 on listening interface for SSL/VPN configuration
  • In case of IPsec, don't forget to configure the remote peer too.[/ol]

     

    You can test your link monitor using the command diagnose sys link-monitor status all

     

    Hope this will help you.

     

    BR 

     

    • sw2090
    SuperUser
    sw2090
    SuperUser
    June 10, 2020

    I always already fail at 1.

     

    My FGT does not allow me to set up a  second default route when I use sdwan.

    I would like to have one Fallback parallel to sdwan but cannot set up the neccessary routing.

    SecurityPlus
    SecurityPlus
    Explorer III
    June 10, 2020
    sw2090, what do you mean when you say “always already fail at 1”?
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