[ale] can anyone explain this?

Dow Hurst dhurst at kennesaw.edu
Mon Dec 17 14:57:37 EST 2001


Are you indicating that the network load on his linux router is forcing
dropped icmp packets?  I think he has stated the load is low on his
network.  I think you have a point about his needing to check his /proc
icmp settings.  However, both network client boxes should show the same
result if the router is misconfigured.  Unless he has different rules on
the router for each box behind the router. I think we need to see a
traceroute from both boxes.  Testing the linux and win boxes by changing
the DNS server entries from primary to secondary and back would test for
his suggested mirroring error.  Am I correct?
Dow

PS. Replying to questions on ALE is fun, but I have to get busy and get
some work done before the day is over! ;)


 
tewkewl at mindspring.com wrote:
> 
> It looks like both ip addresses you are pinging are the same, so dns is correct on both of them.
> 
> but if the linux box is routing for your home network, depending on the proc. it has, it might be dropping icmp to perform routing functions for the rest of the network.  a good test would be to re-ping yoru work address and check packet loss, then ping google or yahoo and check for packet loss...  It is very possible for the linux machine to route icmp for one host but drop icmp destined for itself based on cpu load.
> 
> -Patrick
> 
> Christopher Bergeron <christopher at bergeron.com> wrote:
> > I have a few boxen on my internal home network (192.168.0.x); among them are
> a few linux boxes and 1 lowly win 2k box.
> 
> Here's the inconceiveable part:  My work domain:  bass-associates.com just
> recently changed Network Solutions DNS entries to point at _our_ work DNS
> server.  Now, when I try to ping my work domain from my win box at
> home(which gateways out of a linux box) I get this:
> ----------------------------------------------------------------------------
> ---------
> C:\>time
> The current time is: 23:11:26.29
> Enter the new time:
> 
> C:\>ping www.bass-associates.com
> 
> Pinging www.bass-associates.com [12.108.240.165] with 32 bytes of data:
> 
> Reply from 12.108.240.165: bytes=32 time=40ms TTL=241
> Reply from 12.108.240.165: bytes=32 time=30ms TTL=241
> Reply from 12.108.240.165: bytes=32 time=30ms TTL=241
> Reply from 12.108.240.165: bytes=32 time=30ms TTL=241
> 
> Ping statistics for 12.108.240.165:
>     Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
> Approximate round trip times in milli-seconds:
>     Minimum = 30ms, Maximum =  40ms, Average =  32ms
> ----------------------------------------------------------------------------
> ----------
> Yet from my linux box (the gateway for the winbox), I get this:
> 
> [root at proto1 /]# date; ping www.bass-associates.com -c 3
> Fri Dec 14 23:01:30 EST 2001
> PING www.bass-associates.com (12.108.240.165) from 24.98.82.217 : 56(84)
> bytes of data.
> 
> --- www.bass-associates.com ping statistics ---
> 3 packets transmitted, 1 packets received, 66% packet loss
> round-trip min/avg/max/mdev = 74.240/74.240/74.240/0.000 ms
> ----------------------------------------------------------------------------
> ------------
> 
> The linux box(gateway) is getting 66% packet loss, and the win box isn't!!!
> DoH!!!
> Has the win box somehow gotten more accurate(/recent) DNS info?  The linux
> box (gateway) has it's clock set daily to the National Observatory / Naval
> Atomic Clock so it's the accurate one.   I use the win2k box to browse, but
> I use the linux for everything else [pron: important].  Could the winbox
> have gotten DNS info from sites it browses to or something?  When I ping by
> IP address, I get fast response time from _both_ machines.
> 
> This whole thing has me absolutely befuddled...
> Does anyone have any clues/ideas/suggestions about what is going on?
> 
> Much respect in advance!
> CB
> 
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-- 
__________________________________________________________
Dow Hurst                   Office: 770-499-3428
Systems Support Specialist  Fax:    770-423-6744
1000 Chastain Rd.
Chemistry Department SC428  Email:dhurst at kennesaw.edu
Kennesaw State University         Dow.Hurst at mindspring.com
Kennesaw, GA 30144
*********************************
*Computational Chemistry is fun!*
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