Unable to access router when uplink goes down

Dan_s_97
Here to help

Unable to access router when uplink goes down

This seems like a weird one to me

 

We have the  following setup 

 

             WAN1 __________ ROUTER 1 __________ internet 1 

           /

MX 1-

           \

             WAN 2 __________ ROUTER 2 _________ internet 2

during normal operation - from the internal network we can access both devices  from 10.1.1.5 can reach both 192.168.0.1 and 192.168.1.1

 

But when Internet 1  goes down , i can no longer access/ping  ROUTER 1 even though its connect internally , or from the TOOLS on the mx device , the device is up and working and i can access if we direct connect to it 


5 Replies 5
alemabrahao
Kind of a big deal
Kind of a big deal

 

 

If I'm not mistaken when WAN1 fails, the MX changes its active uplink to WAN2. In failover mode, the MX may stop sending traffic out WAN1 entirely, including internal pings because the MX considers WAN1 “down” and removes its route from the routing table.

I am not a Cisco Meraki employee. My suggestions are based on documentation of Meraki best practices and day-to-day experience.

Please, if this post was useful, leave your kudos and mark it as solved.
Dan_s_97
Here to help

I just read this on another forum post 

 

But is there a way around this ? id prefer not to use a static route and a new subnet 

alemabrahao
Kind of a big deal
Kind of a big deal

If you want both WANs to stay logically active, even when one loses Internet, enabling load balancing can help keep routes alive.

I am not a Cisco Meraki employee. My suggestions are based on documentation of Meraki best practices and day-to-day experience.

Please, if this post was useful, leave your kudos and mark it as solved.
PhilipDAth
Kind of a big deal
Kind of a big deal

No.  Once the WAN port is marked as down, no user traffic will go over it.

RWelch
Kind of a big deal
Kind of a big deal

When a WAN interface on the MX is down, the MX will not route traffic to that interface from the LAN.

This includes traffic destined for the WAN subnet (e.g., the router IP).

This is to prevent routing issues and ensure proper failover behavior.

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