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akarpas
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Cant ping one network device via GRE while able to ping all other devices.

Wed Oct 17, 2018 11:59 pm

OK have added a simple network picture to simplify my description.
3 sites A, B and C
GRE tunnel between A and B
GRE tunnel Between C and B
GRE tunnels works no problem!
on site B i have device x.x.x.10 i'm able to ping that device from site C via tunnel as well as all other devices on that network.
From site A from any PC I may ping any device on site B but not the device x.x.x.10 via GRE, x.x.x.10 ping timing out. If i ping x.x.x.10 from site A router itself ping is successful :D Did i mention what i may ping any other device? Yes I can ping any other devise on site B but not x.x.x.10 :D
Where is the problem? cause I'm giving up already unless its something to do with ISP :D
Any smart ideas.?
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xvo
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Re: Cant ping one network device via GRE while able to ping all other devices.

Thu Oct 18, 2018 12:28 am

And nothing special about x.x.x.10 in mikrotikB config?
No firewall/NAT?
 
akarpas
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Re: Cant ping one network device via GRE while able to ping all other devices.

Thu Oct 18, 2018 9:16 am

And nothing special about x.x.x.10 in mikrotikB config?
No firewall/NAT?
On router B on NAT i have just a usual masquerada rule, and some port forward rules, on firewall just basic firewall nothing what would stop computers on A to ping specific device an site B even i can ping it from A router.
 
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xvo
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Re: Cant ping one network device via GRE while able to ping all other devices.

Fri Oct 19, 2018 12:54 am

I suggest you to try to find the step on which the packet from A network to your mysterious host on B is lost:
use torch, packet sniffer or just create a couple of rules on top of the firewall forward chain both on A and B routers - one rule for way from A network to x.x.x.10, and one for way back.

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