Re: UDP network problem

J.D. Bakker (bakker@thorgal.et.tudelft.nl)
Wed, 20 Aug 1997 11:31:04 +0200

>> > 4008 bytes from 163.164.61.245: icmp_seq=1 ttl=64 time=10.9 ms
>> > 4008 bytes from 163.164.61.245: icmp_seq=2 ttl=64 time=11.0 ms
>>
>> That's a little different. mshar's problem is on sending UDP packets
>> but ping send ICMP echo packets. It can't prove the UDP code in kernel
>> do not have bugs.
>
>Follow the kernel code path for both - it goes the same way

Ah, so this shouldn't be happening:

[bakker@jolan bakker]# ping -f -c 10 -s 7988 -v leon
PING leon.et.tudelft.nl (130.161.42.51): 7988 data bytes
.
--- leon.et.tudelft.nl ping statistics ---
10 packets transmitted, 10 packets received, 0% packet loss
round-trip min/avg/max = 2.2/2.2/2.3 ms
[bakker@jolan bakker]# ping -f -c 10 -s 7989 -v leon
PING leon.et.tudelft.nl (130.161.42.51): 7989 data bytes
................................................................................
................................................................................
................................................................................
................................................................................
..............
[^C]
--- leon.et.tudelft.nl ping statistics ---
336 packets transmitted, 2 packets received, 99% packet loss
round-trip min/avg/max = 2.2/2.2/2.3 ms

...and...

[bakker@leon bakker]# ping -f -c 10 -s 7988 -v jolan
PING jolan.et.tudelft.nl (130.161.40.92): 7988 data bytes
.
--- jolan.et.tudelft.nl ping statistics ---
10 packets transmitted, 10 packets received, 0% packet loss
round-trip min/avg/max = 2.2/2.2/2.5 ms
[bakker@leon bakker]# ping -f -c 10 -s 7989 -v jolan
PING jolan.et.tudelft.nl (130.161.40.92): 7989 data bytes
................................................................................
................................................................................
...........................................................................
[^C]
--- jolan.et.tudelft.nl ping statistics ---
235 packets transmitted, 0 packets received, 100% packet loss

...but...

[bakker@inpc28 bakker]# ping -f -c 10 -s 7989 -v leon
PING leon.et.tudelft.nl (130.161.42.51): 7989 data bytes
.
--- leon.et.tudelft.nl ping statistics ---
10 packets transmitted, 10 packets received, 0% packet loss
round-trip min/avg/max = 2.6/4.3/6.0 ms
[bakker@inpc28 bakker]# ping -f -c 10 -s 7989 -v jolan
PING jolan.et.tudelft.nl (130.161.40.92): 7989 data bytes
................................................................................
................................................................................
................................................................................
............
[^C]
--- jolan.et.tudelft.nl ping statistics ---
252 packets transmitted, 0 packets received, 100% packet loss

inpc28: P5, 2.1.36, KNE100TX (de4x5 v0.5)
leon: 4P6 (Goliath), 2.0.30 SMP, KNE100TX (de4x5 v0.442)
jolan: 2P6 (Asus), 2.1.38 SMP, KNE100TX (de4x5 v0.52)

All are connected (half-duplex) to a Bay Fast Ethernet-switch.

jolan seems to have trouble with sending/receiving anything over 7988 bytes.
Is this a known 2.1.38 problem ?

Sincerely,

Jan-Derk Bakker.

Jan-Derk Bakker
Official Usenet Net.scum; see http://www.netscum.net