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New Member

Strange ping behaviour while router pings wifi device

Hi

Perhaps a little bit off-topic.....

I own an HP ProCurve1700-24 (J9080A) switch who has connected several windows and linux machines

A Cisco 877 is connected as well, acting as the LAN default gateway

Also a D-Link DWL2000-AP access point is connected to HP switch

A Samsung wifi device is connected to wifi access point

The windows and linux machine ping the Samsung wifi device with a time variable between 20ms and 300ms

If i ping the samsung device from 877 console the latency is very low (3000 ping , 1/4/200 ms)

The strange thing, is while i ping samsung device from Cisco console, the latency time from win/linux machine to samsung device drops immediately to 3ms stable

When cisco ends to ping samsung device , win/linux machine latency turns back to high values (still from 20 to 300ms variable)

What's the matter ??

Why idle time from win/linux to wifi is usually high ?

Where should I work to solve the issue ?

Thank you very much

2 REPLIES

Strange ping behaviour while router pings wifi device

To clarify

Your Cisco 887 is the the L3 Routing device and all the devices in question are on the same Vlan yes?

Assuming I have read it correctly, it sounds like the issue lies in the link between the switch and the 887 router.

If you ping the default gateway from the Samsung device, are the ping times high still?

Don't forget that when pinging another device on your Vlan, the frames are forwarded by the switch using the Layer 2 MAC address so they do not pass up the link to the routed device.

New Member

Strange ping behaviour while router pings wifi device

All devices are on the same Vlan ( or better there is no more vlan declaration on HP switch , only the default Vlan1 for all ethernet ports)

I've not yet tried to ping the router from the Samsung device itself...

And yes, there is no routing path between devices, so when I ping the samsung device via wifi, all packets coming from either the win/linux machines or the router ethernet, pass through the HP switch, then through the access point , reaching finally the samsung device.

Pratically no routing is involved, Look at the 877 ethernet as it would be another common LAN machine....

The strange thing is when 877 is pinging (effectively with very low latency) the samsung device, it seems something like it "opens" a choked path to it, and also the other machine on LAN can reach samsung machine with very low answer time....

When cisco ends its packets , the LAN machines ping time returns higher...

That's all, any idea ?

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