Ping timeouts - what do they mean?

[Guest]

I have an Acer 6460 laptop with wifi and lan cards, running xp sp2. I also
have a DLink DI-524 wireless router.

I have found the network performance to be somewhat eratic, so I ran the
network scan function in windows "help and support"

It shows that about 50% of the ping requests from my machine to the wireless
router time out. Why is that, and what does it mean? I know it means that no
response was received within the TTL of the ping request, but why does this
happen, and how do I fix it?

The router is not doing anything else, so I assume its not a capacity issue.
Its not a range / signal strength issue, because the signal strength is
reported as Excellent, and the laptop is right next to the router.

Even if I increase the TTL on the ping, it still times out. This suggests to
me that either the ping request gets lost, or the reply gets lost ? Does this
make sense to anyone out there?

Any help would be greatly appreciated.

 

[Barb Bowman]

so you see this with either a wired or wireless connection? if you
see it with wired, what is going on locally on the laptop? and if
you see this on both wired and wireless, are there logs on the
router that you can check? look for activity like port scans. this
kind of activity can overwhelm the processor in the router.

I have an Acer 6460 laptop with wifi and lan cards, running xp sp2. I also
have a DLink DI-524 wireless router.

I have found the network performance to be somewhat eratic, so I ran the
network scan function in windows "help and support"

It shows that about 50% of the ping requests from my machine to the wireless
router time out. Why is that, and what does it mean? I know it means that no
response was received within the TTL of the ping request, but why does this
happen, and how do I fix it?

The router is not doing anything else, so I assume its not a capacity issue.
Its not a range / signal strength issue, because the signal strength is
reported as Excellent, and the laptop is right next to the router.

Even if I increase the TTL on the ping, it still times out. This suggests to
me that either the ping request gets lost, or the reply gets lost ? Does this
make sense to anyone out there?

Any help would be greatly appreciated.

--

Barb Bowman
MS Windows-MVP
http://www.microsoft.com/windowsxp/expertzone/meetexperts/bowman.mspx
http://blogs.digitalmediaphile.com/barb/

 

[Guest]

Thanks for responding Barb.

It happens on both the wired and the wireless adapters.

I don't think the router is being port scanned - it is not connected
directly to the net. (I have a wierd setup - I have a USB based broadband
connection that hangs off one of the other machines on my home network (ie my
gateway) - the wireless router is just there to let the Laptop access the
gateway machine). The pings are directed at this machine. There is no
evidence of a port scan on that machine. In fact, I get the same result if I
disconnect my network from th eInternet completely.

There is no other activity on either the laptop or the gateway machine.

 

[Barb Bowman]

ok, the topology is confusing and may have some impact. is DHCP and
NAT turned off on the 524 since something else is serving DHCP?

what is connected to what here? need full topology to understand
what might be going on.

Thanks for responding Barb.

It happens on both the wired and the wireless adapters.

I don't think the router is being port scanned - it is not connected
directly to the net. (I have a wierd setup - I have a USB based broadband
connection that hangs off one of the other machines on my home network (ie my
gateway) - the wireless router is just there to let the Laptop access the
gateway machine). The pings are directed at this machine. There is no
evidence of a port scan on that machine. In fact, I get the same result if I
disconnect my network from th eInternet completely.

There is no other activity on either the laptop or the gateway machine.

--

Barb Bowman
MS Windows-MVP
http://www.microsoft.com/windowsxp/expertzone/meetexperts/bowman.mspx
http://blogs.digitalmediaphile.com/barb/

 

[Guest]

OK, bit difficult without a picture, but here goes:

Machine 1: Laptop
NIC1: Intel(R) PRO/Wireless 3945ABG
Static IP: 192.168.0.20,
Subnet 255.255.0.0
default gateway, DNS and WINS 192.168.0.1
NIC2: Broadcom NetLink (TM) Gigabit Ethernet
Static IP: 192.168.0.21,
Subnet 255.255.0.0
default gateway, DNS and WINS 192.168.0.1

Router: DI-524
IP: 192.168.0.2
SUBNET 255.255.255.0 <<--- note the third .255. - different from other
machines. This hard coded in this router.

Machine 2:
Lan connection static IP: 192.168.0.1
Has Wireless Broadband modem connected through USB port, configured as
shared. Broadband connectino has dynamic IP address assigned by network
operator at connection time.
Apparently this machine is operating as DNS and WINS server - based on reult
of MS-netscan run on Machine 1 returns DNSServerSearchOrder = 192.168.0.1
(PASSED), and WINSPrimaryServer = 192.168.0.1 (PASSED)

 

[Barb Bowman]

I'm confused. The laptop has two NICs. One is wireless. What/where
is the second wired one connected? you need to pick one of these to
do trouble shooting, but having both connected is going to
complicate things.

I also don't understand how the 524 is configured. Is DHCP turned
off? Is NAT? which ports are you using and what is plugged into
what?

OK, bit difficult without a picture, but here goes:

Machine 1: Laptop
NIC1: Intel(R) PRO/Wireless 3945ABG
Static IP: 192.168.0.20,
Subnet 255.255.0.0
default gateway, DNS and WINS 192.168.0.1
NIC2: Broadcom NetLink (TM) Gigabit Ethernet
Static IP: 192.168.0.21,
Subnet 255.255.0.0
default gateway, DNS and WINS 192.168.0.1

Router: DI-524
IP: 192.168.0.2
SUBNET 255.255.255.0 <<--- note the third .255. - different from other
machines. This hard coded in this router.

Machine 2:
Lan connection static IP: 192.168.0.1
Has Wireless Broadband modem connected through USB port, configured as
shared. Broadband connectino has dynamic IP address assigned by network
operator at connection time.
Apparently this machine is operating as DNS and WINS server - based on reult
of MS-netscan run on Machine 1 returns DNSServerSearchOrder = 192.168.0.1
(PASSED), and WINSPrimaryServer = 192.168.0.1 (PASSED)

--

Barb Bowman
MS Windows-MVP
http://www.microsoft.com/windowsxp/expertzone/meetexperts/bowman.mspx
http://blogs.digitalmediaphile.com/barb/

 

[RalfG]

It may not make any practical difference in your setup but 255.255.255.0 is
the correct mask for the 192.168.0.x subnet. 255.255.0.0 would be the mask
for 192.168.x.x addresses.

Check that you have set up the DI-524 to function only as a wireless access
point (no routing, DHCP, etc.) and using a different radio channel than the
wireless broadband modem is set to. (is there a reason Machine 1 can't
connect wirelessly directly to the modem?) There should also be a minimum
distance between the two wireless devices (router, modem) to avoid radio
frequency interference, or turn off the radio in the modem if it is not
being used.

It has been the case that for wireless connections Atheros chipsets (DI-524)
and Broadcom chipsets don't always work well together, so there could be
some hardware incompatibility at play here with the Intel wireless as well.