Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!uwvax!umn-d-ub!tperala From: tperala@umn-d-ub.D.UMN.EDU (Tim Perala) Newsgroups: comp.protocols.tcp-ip Subject: ICMP Multiple Echo Replies Keywords: ICMP echo reply Message-ID: <1131@umn-d-ub.D.UMN.EDU> Date: 29 Jun 89 20:11:48 GMT Organization: U of Minnesota-Duluth, Information Services Lines: 48 I have been getting strange behaviour when pinging a particular host on the Internet. I have not seen this behaviour with any other host. Here is a script of what is happening... Script started on Thu Jun 29 14:41:41 1989 1% /etc/ping multimax.encore.com PING multimax.encore.com: 56 data bytes 64 bytes from 129.91.1.14: icmp_seq=0. time=215. ms 64 bytes from 129.91.1.14: icmp_seq=1. time=221. ms 64 bytes from 129.91.1.14: icmp_seq=2. time=210. ms 64 bytes from 129.91.1.14: icmp_seq=3. time=213. ms 64 bytes from 129.91.1.14: icmp_seq=3. time=220. ms 64 bytes from 129.91.1.14: icmp_seq=4. time=226. ms 64 bytes from 129.91.1.14: icmp_seq=5. time=229. ms 64 bytes from 129.91.1.14: icmp_seq=6. time=275. ms 64 bytes from 129.91.1.14: icmp_seq=7. time=1064. ms 64 bytes from 129.91.1.14: icmp_seq=8. time=284. ms 64 bytes from 129.91.1.14: icmp_seq=8. time=289. ms 64 bytes from 129.91.1.14: icmp_seq=9. time=622. ms 64 bytes from 129.91.1.14: icmp_seq=10. time=231. ms 64 bytes from 129.91.1.14: icmp_seq=12. time=598. ms 64 bytes from 129.91.1.14: icmp_seq=13. time=619. ms 64 bytes from 129.91.1.14: icmp_seq=14. time=307. ms 64 bytes from 129.91.1.14: icmp_seq=15. time=243. ms 64 bytes from 129.91.1.14: icmp_seq=16. time=224. ms 64 bytes from 129.91.1.14: icmp_seq=17. time=211. ms ^C ----multimax.encore.com PING Statistics---- 18 packets transmitted, 19 packets received, -5% packet loss round-trip (ms) min/avg/max = 210/342/1064 2% ^D script done on Thu Jun 29 14:42:34 1989 Notice that I receive multiple replies on some of the requests. I have no reason to believe that my ping program is in error. What are some possible explanations for this behaviour, aside from the obvious, that the recipient of the request is actually generating multiple replies from a single ICMP echo request? Just curious. Tim Perala Systems Programmer Information Services University of Minnesota, Duluth (218) 726-6122