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Member
Posts: 179
Registered: ‎04-27-2013
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4G modem answering pings and messing LB watchdog

I am managing a setup with two DSL lines and a 4G modem for load balancing. 

 

Problem is the 4G modem/router answers pings to 8.8.8.8 even if the line is down. 

 

You send it 

 

ping 8.8.8.8 (or whatever)

and the modem replies 

ping answer from 192.168.5.1

 

so, packets are still sent over that route and of course it’s a mess. 

 

What would be the best idea for a script to check that ?

@mehuneau
SuperUser
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Re: 4G modem answering pings and messing LB watchdog

Maybe a dirty (and fast) way ... a drop rule, before the related/established in the WAN_LOCAL ruleset, for echo-replies from 192.168.5.1 ?

Cheers,

jonatha

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Re: 4G modem answering pings and messing LB watchdog

Without more info, this is hard to answer.

 

  1. Are you sure the ping is even being sent to the 4G modem?  How did you verify that?
  2. What is the device at 192.168.5.1?
Member
Posts: 179
Registered: ‎04-27-2013
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Solutions: 2

Re: 4G modem answering pings and messing LB watchdog

Sorry,

 

yes, I verified from the CLI and from my laptop that any ping sent to the modem is answered by the modem’s own IP if the wan is down. 

 

In my case the modem is the 192.168.5.1

@mehuneau
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Re: 4G modem answering pings and messing LB watchdog


@mehuneau wrote:

Sorry,

 

yes, I verified from the CLI and from my laptop that any ping sent to the modem is answered by the modem’s own IP if the wan is down. 

 

In my case the modem is the 192.168.5.1


What kind of modem is this?

 

Member
Posts: 179
Registered: ‎04-27-2013
Kudos: 11
Solutions: 2

Re: 4G modem answering pings and messing LB watchdog

The modem is a Netgear LB2120-100PES

@mehuneau
Member
Posts: 252
Registered: ‎08-15-2015
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Re: 4G modem answering pings and messing LB watchdog


@mehuneau wrote:

The modem is a Netgear LB2120-100PES


That's what I'm using.  Change it to bridge mode and set your WAN port connected to it to DHCP.  That's what I've done and it's been working perfectly for fail-over and fail-back for over a year.

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