[LARTC] Random ping jumps
Artūras Šlajus
x11@h2o.pieva.net
Thu, 08 Jan 2004 22:01:28 +0200
R. Steve McKown wrote:
> Can you provide some more detail on your network configuration? I'm unclear
> if the linux server is your internet router or just another client computer
> on your local LAN
It's network router.
> , where the test pings to "the internet" are going (i.e.
> nexthop router, etc.), and if/where CIPE tunnels are involved in the
> equation. Perhaps a small network map would be helpful.
No CIPE (whatever is that ;-). Nexthop? You mean gateway?
eth0:1 Link encap:Ethernet HWaddr 00:50:22:B1:67:6D
inet addr:81.7.84.36 Bcast:81.255.255.255 Mask:255.0.0.0
UP BROADCAST RUNNING MULTICAST MTU:1492 Metric:1
Interrupt:10 Base address:0xd000
gateway: 81.7.84.1
Map is at http://h2o.pieva.net/net.png
> I'm also unclear about the pings that you've tried. After you've shown the
> network map, perhaps you can identify the two machines (and interfaces)
> involved in each of the different ping tests you've performed.
The machine is totaly random.
x11@rasnet:~$ traceroute fortas.ktu.lt
traceroute to fortas.ktu.lt (193.219.160.131), 30 hops max, 38 byte packets
1 adsl-213-190-40-129.takas.lt (213.190.40.129) 26.269 ms 23.333 ms 25.156 ms
2 fe22-acc0-tai.kns.telecom.lt (212.59.7.233) 63.079 ms 33.146 ms 26.117 ms
3 telecom-gw.is.lt (193.219.13.99) 35.978 ms 26.476 ms 103.138 ms
4 litnet-gw.is.lt (193.219.13.98) 22.715 ms 24.531 ms 209.984 ms
5 cat6506-p2-1.kttc.litnet.lt (193.219.62.125) 52.826 ms 98.040 ms 81.609 ms
6 ktu-lan.litnet.lt (193.219.61.252) 38.696 ms 182.582 ms 241.836 ms
7 fortas.ktu.lt (193.219.160.131) 215.523 ms 126.815 ms 29.217 ms
x11@rasnet:~$ traceroute cs.mes.lt
traceroute to cs.mes.lt (193.219.67.253), 30 hops max, 38 byte packets
1 adsl-213-190-40-129.takas.lt (213.190.40.129) 748.174 ms 66.331 ms 135.586 ms
2 fe22-acc0-tai.kns.telecom.lt (212.59.7.233) 21.645 ms 21.588 ms 24.597 ms
3 telecom-gw.is.lt (193.219.13.99) 30.584 ms 31.065 ms 29.612 ms
4 litnet-gw.is.lt (193.219.13.98) 24.602 ms 143.212 ms 143.096 ms
5 cat6506-p2-1.kttc.litnet.lt (193.219.62.125) 292.196 ms 163.870 ms 84.549 ms
6 ktu-lan.litnet.lt (193.219.61.252) 84.982 ms 54.801 ms 69.143 ms
7 diz.ktu.lt (193.219.67.253) 33.831 ms 29.877 ms 30.005 ms
64 bytes from diz.ktu.lt (193.219.67.253): icmp_seq=5 ttl=59 time=34.8 ms
64 bytes from diz.ktu.lt (193.219.67.253): icmp_seq=6 ttl=59 time=32.6 ms
64 bytes from diz.ktu.lt (193.219.67.253): icmp_seq=7 ttl=59 time=33.1 ms
64 bytes from diz.ktu.lt (193.219.67.253): icmp_seq=8 ttl=59 time=324 ms
64 bytes from diz.ktu.lt (193.219.67.253): icmp_seq=9 ttl=59 time=836 ms
64 bytes from diz.ktu.lt (193.219.67.253): icmp_seq=10 ttl=59 time=850 ms
64 bytes from diz.ktu.lt (193.219.67.253): icmp_seq=11 ttl=59 time=321 ms
64 bytes from diz.ktu.lt (193.219.67.253): icmp_seq=12 ttl=59 time=147 ms
64 bytes from diz.ktu.lt (193.219.67.253): icmp_seq=13 ttl=59 time=115 ms
64 bytes from diz.ktu.lt (193.219.67.253): icmp_seq=14 ttl=59 time=118 ms
64 bytes from diz.ktu.lt (193.219.67.253): icmp_seq=15 ttl=59 time=107 ms
64 bytes from diz.ktu.lt (193.219.67.253): icmp_seq=16 ttl=59 time=107 ms
64 bytes from diz.ktu.lt (193.219.67.253): icmp_seq=17 ttl=59 time=272 ms
64 bytes from diz.ktu.lt (193.219.67.253): icmp_seq=18 ttl=59 time=312 ms
64 bytes from diz.ktu.lt (193.219.67.253): icmp_seq=19 ttl=59 time=102 ms
64 bytes from diz.ktu.lt (193.219.67.253): icmp_seq=20 ttl=59 time=107 ms
64 bytes from diz.ktu.lt (193.219.67.253): icmp_seq=21 ttl=59 time=114 ms
64 bytes from diz.ktu.lt (193.219.67.253): icmp_seq=22 ttl=59 time=89.8 ms
64 bytes from diz.ktu.lt (193.219.67.253): icmp_seq=23 ttl=59 time=91.2 ms
x11@rasnet:~$ traceroute cs.bbd.lt
traceroute to cs.bbd.lt (193.219.184.7), 30 hops max, 38 byte packets
1 adsl-213-190-40-129.takas.lt (213.190.40.129) 23.803 ms 24.813 ms 56.163 ms
2 fe22-acc0-tai.kns.telecom.lt (212.59.7.233) 171.425 ms 21.174 ms 24.321 ms
3 telecom-gw.is.lt (193.219.13.99) 27.882 ms 30.782 ms 26.219 ms
4 litnet-gw.is.lt (193.219.13.98) 22.842 ms 23.025 ms 24.079 ms
5 cat6506-p2-1.kttc.litnet.lt (193.219.62.125) 24.201 ms 25.130 ms 27.256 ms
6 ktu-lan.litnet.lt (193.219.61.252) 26.811 ms 27.362 ms 27.785 ms
7 193.219.184.7 (193.219.184.7) 27.928 ms 29.185 ms 28.067 ms
x11@rasnet:~$ ping cs.bbd.lt
PING cs.bbd.lt (193.219.184.7) 56(84) bytes of data.
64 bytes from 193.219.184.7: icmp_seq=1 ttl=123 time=133 ms
64 bytes from 193.219.184.7: icmp_seq=2 ttl=123 time=122 ms
64 bytes from 193.219.184.7: icmp_seq=3 ttl=123 time=118 ms
64 bytes from 193.219.184.7: icmp_seq=4 ttl=123 time=109 ms
64 bytes from 193.219.184.7: icmp_seq=5 ttl=123 time=725 ms
64 bytes from 193.219.184.7: icmp_seq=6 ttl=123 time=668 ms
64 bytes from 193.219.184.7: icmp_seq=7 ttl=123 time=120 ms
64 bytes from 193.219.184.7: icmp_seq=8 ttl=123 time=102 ms
64 bytes from 193.219.184.7: icmp_seq=9 ttl=123 time=91.5 ms
64 bytes from 193.219.184.7: icmp_seq=10 ttl=123 time=91.7 ms
> I had a similar problem recently. Interestingly, it
> turned out to be bad hardware.
Another person told me that bad hw could be reason. But it works for
LAN perfectly.
> Moved the boot media to an identically
> configured machine and the problem went away. Returned the boot media to the
> original machine and the problem returned.
Sad, but i can't do that :(
My /etc/network/interfaces:
auto eth0
iface eth0 inet static
address 192.168.0.1
netmask 255.255.255.0
autho eth0:1
iface eth0:1 inet static
address 81.7.84.36
netmask 255.0.0.0
gateway 81.7.84.1
mtu 1492
I hadn't set mtu before. After setting it ping times decreased. (afterall it's dsl).
Also, what exatcly net/ipv4/tcp_low_latency = 1 in sysctl do?
--
Sincerely, Artūras Šlajus
ICQ: 157929934
Jabber: arturaz@akl.lt
Oh, and please'o'please use UTF-8! :-)