(I apologize that this isn’t a programming question. But it does relate to my 
understanding of networks and Apple network gear…)

I’m trying to diagnose some frustrating connectivity problems between my MBP, 
my Airport Extreme base station, and my Airport Express. The latter is being 
used just for AirPlay music streaming, not as a base station in its own right. 
AirPlay is really, really intermittent; most of the time iTunes can’t connect, 
and when it does it cuts out after a few seconds.

So in a shell I’m pinging the Airport Express:

$ ping 10.0.1.5
PING 10.0.1.5 (10.0.1.5): 56 data bytes
Request timeout for icmp_seq 0
Request timeout for icmp_seq 1
Request timeout for icmp_seq 2
Request timeout for icmp_seq 3
Request timeout for icmp_seq 4
Request timeout for icmp_seq 5
…

And so on, no responses at all. Then 45 seconds later:

…
Request timeout for icmp_seq 45
64 bytes from 10.0.1.5: icmp_seq=0 ttl=255 time=46896.140 ms
Request timeout for icmp_seq 47
64 bytes from 10.0.1.5: icmp_seq=6 ttl=255 time=42821.925 ms
64 bytes from 10.0.1.5: icmp_seq=7 ttl=255 time=43049.368 ms
64 bytes from 10.0.1.5: icmp_seq=8 ttl=255 time=42086.386 ms
64 bytes from 10.0.1.5: icmp_seq=9 ttl=255 time=41398.708 ms

Something’s been buffering up these ICMP packets (either the pings or the 
responses) for up to 46 seconds! That seems weird to me; my probably-naive 
understanding is that IP packets will get dropped on the floor if they can’t be 
delivered. I think 802.11 makes some attempts to retransmit, but for _45 
seconds_?! And ICMP packets of all things — aren’t those used only for ping and 
traceroute, i.e. to check connectivity? Making aggressive delivery attempts 
seems counterproductive for those.

—Jens (who just wants to play his damn music, really)
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