version=pmwiki-2.2.130 ordered=1 urlencoded=1 agent=Mozilla/5.0 (X11; OpenBSD amd64; rv:76.0) Gecko/20100101 Firefox/76.0 author=jrmu charset=UTF-8 csum= ctime=1597221268 host=38.81.163.143 name=Openbsd.Ping rev=1 targets= text=(:title Troubleshooting with Ping:)%0a%0aOne important tool for troubleshooting networking is ping. To test if a device has proper networking, you can run ping on an IP address or a hostname. Once you are done, press CTRL+C (abbreviated ^C):%0a%0a[@%0a$ ping ircnow.org%0aPING ircnow.org (209.141.39.173): 56 data bytes%0a64 bytes from 209.141.39.173: icmp_seq=0 ttl=244 time=251.636 ms%0a64 bytes from 209.141.39.173: icmp_seq=1 ttl=244 time=252.236 ms%0a64 bytes from 209.141.39.173: icmp_seq=2 ttl=244 time=249.526 ms%0a64 bytes from 209.141.39.173: icmp_seq=3 ttl=244 time=249.869 ms%0a64 bytes from 209.141.39.173: icmp_seq=4 ttl=244 time=248.836 ms%0a64 bytes from 209.141.39.173: icmp_seq=5 ttl=244 time=251.230 ms%0a64 bytes from 209.141.39.173: icmp_seq=6 ttl=244 time=249.227 ms%0a64 bytes from 209.141.39.173: icmp_seq=7 ttl=244 time=249.550 ms%0a^C%0a--- ircnow.org ping statistics ---%0a8 packets transmitted, 8 packets received, 0.0%25 packet loss%0around-trip min/avg/max/std-dev = 248.836/250.264/252.236/1.174 ms%0a@]%0a%0aping uses the Internet Control Message Protocol (ICMP) to test for problems. Here, we see it takes roughly 250 milliseconds for ircnow.org to reply to our messages. Of the 8 packets sent, all 8 were received, so we have 0 packet loss.%0a%0aIf you need to test out IPv6, then use the ping6 command. For both IPv4 and IPv6, you may find it helpful to bind to a specific IP address (send packets using a specific IP address). In that case, use the option -I. For example:%0a%0a[@%0a$ ping6 -I 1234:5678:abcd:ef::1 ircnow.org%0a@]%0a%0aThis will force ping6 to send and receive packets using the (fake) IPv6 address 1234:5678:abcd:ef::1.%0a%0aSometimes, you may see ping results that require further investigation:%0a%0a[@%0a--- fake.ircnow.org ping statistics ---%0a2779223 packets transmitted, 2669400 packets received, 4.0%25 packet loss%0around-trip min/avg/max/std-dev = 510.548/600.687/535545.801/958.211 ms%0a@]%0a%0aHere, our ping suffers 4%25 packet loss. This is quite high and should be investigated. Perhaps there is an issue with the hardware or the networking equipment is faulty. The average latency of 600ms is also very high. Ideally, when the client and server are on the same continent, latency should be under 100ms. A latency of around 200ms is average, and anything above 300ms is quite high and feels ''laggy''.%0a%0aIf you get packet loss that is less than 100%25, then some packets are still arriving. Networking is working somewhat, but there may be a misconfiguration somewhere, or faulty hardware. However, if you are getting 100%25 packet loss, then either your hardware is altogether broken, or your configuration is wrong.%0a%0aYou also should check your firewall. Because ping and ping6 both use ICMP, any firewall rules that block ICMP should be disabled. Be careful: rate-limiting ICMP may cause issues. time=1597221268 title=Troubleshooting with Ping author:1597221268=jrmu diff:1597221268:1597221268:=1,44d0%0a%3c (:title Troubleshooting with Ping:)%0a%3c %0a%3c One important tool for troubleshooting networking is ping. To test if a device has proper networking, you can run ping on an IP address or a hostname. Once you are done, press CTRL+C (abbreviated ^C):%0a%3c %0a%3c [@%0a%3c $ ping ircnow.org%0a%3c PING ircnow.org (209.141.39.173): 56 data bytes%0a%3c 64 bytes from 209.141.39.173: icmp_seq=0 ttl=244 time=251.636 ms%0a%3c 64 bytes from 209.141.39.173: icmp_seq=1 ttl=244 time=252.236 ms%0a%3c 64 bytes from 209.141.39.173: icmp_seq=2 ttl=244 time=249.526 ms%0a%3c 64 bytes from 209.141.39.173: icmp_seq=3 ttl=244 time=249.869 ms%0a%3c 64 bytes from 209.141.39.173: icmp_seq=4 ttl=244 time=248.836 ms%0a%3c 64 bytes from 209.141.39.173: icmp_seq=5 ttl=244 time=251.230 ms%0a%3c 64 bytes from 209.141.39.173: icmp_seq=6 ttl=244 time=249.227 ms%0a%3c 64 bytes from 209.141.39.173: icmp_seq=7 ttl=244 time=249.550 ms%0a%3c ^C%0a%3c --- ircnow.org ping statistics ---%0a%3c 8 packets transmitted, 8 packets received, 0.0%25 packet loss%0a%3c round-trip min/avg/max/std-dev = 248.836/250.264/252.236/1.174 ms%0a%3c @]%0a%3c %0a%3c ping uses the Internet Control Message Protocol (ICMP) to test for problems. Here, we see it takes roughly 250 milliseconds for ircnow.org to reply to our messages. Of the 8 packets sent, all 8 were received, so we have 0 packet loss.%0a%3c %0a%3c If you need to test out IPv6, then use the ping6 command. For both IPv4 and IPv6, you may find it helpful to bind to a specific IP address (send packets using a specific IP address). In that case, use the option -I. For example:%0a%3c %0a%3c [@%0a%3c $ ping6 -I 1234:5678:abcd:ef::1 ircnow.org%0a%3c @]%0a%3c %0a%3c This will force ping6 to send and receive packets using the (fake) IPv6 address 1234:5678:abcd:ef::1.%0a%3c %0a%3c Sometimes, you may see ping results that require further investigation:%0a%3c %0a%3c [@%0a%3c --- fake.ircnow.org ping statistics ---%0a%3c 2779223 packets transmitted, 2669400 packets received, 4.0%25 packet loss%0a%3c round-trip min/avg/max/std-dev = 510.548/600.687/535545.801/958.211 ms%0a%3c @]%0a%3c %0a%3c Here, our ping suffers 4%25 packet loss. This is quite high and should be investigated. Perhaps there is an issue with the hardware or the networking equipment is faulty. The average latency of 600ms is also very high. Ideally, when the client and server are on the same continent, latency should be under 100ms. A latency of around 200ms is average, and anything above 300ms is quite high and feels ''laggy''.%0a%3c %0a%3c If you get packet loss that is less than 100%25, then some packets are still arriving. Networking is working somewhat, but there may be a misconfiguration somewhere, or faulty hardware. However, if you are getting 100%25 packet loss, then either your hardware is altogether broken, or your configuration is wrong.%0a%3c %0a%3c You also should check your firewall. Because ping and ping6 both use ICMP, any firewall rules that block ICMP should be disabled. Be careful: rate-limiting ICMP may cause issues.%0a\ No newline at end of file%0a host:1597221268=38.81.163.143