Ping replies from different IPs?

[fwilson]

I was doing some testing on my home network and was having some betwork issues. I would start a ping /t to my router and it would reply for a few second and then time out for a few seconds. In my testing, I noticed that the "Reply From" IP address changed mid-ping. In the following copy/paste, please note the following:

Network setup:

Desktop <ConnectsTo> Router

Router is 10.1.1.1

Desktop is 10.1.1.12

The Desktop is running Vista Ultimate x86

The Router is a Linksys WRT54G

I have 2 more PCs connected directly to the router

Below is the copy/paste from the command prompt. It starts when I was running "ping 10.1.1.1 /t". I stopped it when I saw "Destination host unreachable" from 10.1.1.12 (the host compter running these ping commands).

Reply from 10.1.1.1: bytes=32 time=1ms TTL=64

Reply from 10.1.1.1: bytes=32 time=1ms TTL=64

Reply from 10.1.1.1: bytes=32 time=1ms TTL=64

Reply from 10.1.1.1: bytes=32 time=1ms TTL=64

Reply from 10.1.1.1: bytes=32 time=1ms TTL=64

Reply from 10.1.1.12: Destination host unreachable.

Reply from 10.1.1.12: Destination host unreachable.

Reply from 10.1.1.12: Destination host unreachable.

Ping statistics for 10.1.1.1:

Packets: Sent = 98, Received = 98, Lost = 0 (0% loss),

Approximate round trip times in milli-seconds:

Minimum = 1ms, Maximum = 2ms, Average = 1ms

Control-C

^C

C:\Users\frank>ping 10.1.1.1 /t

Pinging 10.1.1.1 with 32 bytes of data:

Reply from 10.1.1.12: Destination host unreachable.

Reply from 10.1.1.12: Destination host unreachable.

Ping statistics for 10.1.1.1:

Packets: Sent = 2, Received = 2, Lost = 0 (0% loss),

Control-C

^C

C:\Users\frank>ping 10.1.1.12

Pinging 10.1.1.12 with 32 bytes of data:

Reply from 10.1.1.12: bytes=32 time<1ms TTL=128

Reply from 10.1.1.12: bytes=32 time<1ms TTL=128

Ping statistics for 10.1.1.12:

Packets: Sent = 2, Received = 2, Lost = 0 (0% loss),

Approximate round trip times in milli-seconds:

Minimum = 0ms, Maximum = 0ms, Average = 0ms

Control-C

^C

C:\Users\frank>ping 10.1.1.1

Pinging 10.1.1.1 with 32 bytes of data:

Reply from 10.1.1.12: Destination host unreachable.

Reply from 10.1.1.1: bytes=32 time=1ms TTL=64

Reply from 10.1.1.1: bytes=32 time=1ms TTL=64

Reply from 10.1.1.1: bytes=32 time=1ms TTL=64

Ping statistics for 10.1.1.1:

Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),

Approximate round trip times in milli-seconds:

Minimum = 1ms, Maximum = 1ms, Average = 1ms

I'm just not sure what to make of this. Has anyone seen anything like this before? Now, I did just move this PC from another room so could it have been some leftover ARP stuff or something? I was having significant issues with my network yesterday and I was thinking that this might be related. The other PCs were able to ping the router and each other reliably. But this one desktop (10.1.1.12) was having significant issues.

Any thoughts?

Thanks,

Frank

[cluberti]

When a device responds like this, it will show your client IP (as you are seeing) stating that it's not able to communicate at all with the remote host (Destination host unreachable).

I would consider getting a network trace from your client whilst pinging 10.1.1.1 via wireshark or netmon to see what's actually happening. Is the router actually not responding to the ICMP requests, or is something on the client causing it? Hard to say without that raw packet data.

[fwilson]

I can't reproduce this anymore, so no packet data. I guess it's a moot point now. But I was just intrigued by that last ping, where I received data back but it came from multiple IP addresses.