Measuring packet loss


In continuing on with my commitment to describe my favorite network utilities, I bring to you mtr:

$ mtr -r -c 10 mail.prefetch.net

HOST: me Loss% Snt Last Avg Best Wrst StDev
1. 10.238.4.1 0.0% 10 9.2 8.2 5.4 12.6 2.1
2. 68.86.108.13 0.0% 10 9.2 9.4 6.3 14.9 2.8
3. 68.86.106.45 0.0% 10 15.1 10.1 6.9 17.5 3.5
4. 68.86.106.13 0.0% 10 14.0 11.0 5.7 22.1 4.8
5. 68.86.106.9 0.0% 10 14.6 11.4 7.2 18.5 3.6
6. 12.118.120.89 0.0% 10 10.2 10.3 8.2 14.6 2.2
7. tbr1-p012201.attga.ip.att.ne 0.0% 10 23.8 25.8 21.8 33.9 3.6
8. tbr2-cl1.wswdc.ip.att.net 0.0% 10 27.3 26.9 23.7 33.4 3.0
9. ggr2-p390.wswdc.ip.att.net 0.0% 10 23.0 27.6 22.6 41.0 5.6
10. so6-3-0-2488M.ar1.DCA3.gblx. 0.0% 10 26.0 30.4 23.9 43.3 6.3
11. so0-0-0-622M.ar2.CLE1.gblx.n 0.0% 10 130.3 49.8 37.7 130.3 28.4
12. Enet-Inc-Internet.so-0-3-3.a 0.0% 10 51.2 45.9 42.5 54.9 4.0
13. extreme.xlhost.com 0.0% 10 44.2 67.1 41.4 261.4 68.3
14. mail.prefetch.net 0.0% 10 48.3 56.6 41.5 172.9 40.9

mtr allows you to view hop-by-hop latency metrics, and is invaluable for finding busy devices between two endpoints. Some routers will place low QOS priorities on ICMP traffic, so it is important to capture traffic at various intervals to see if a device is truly overloaded.

This article was posted by Matty on 2005-08-29 20:37:00 -0400 EDT