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- When troubleshooting network connectivity.

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The next step after verifying IP information

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with IP Config is to use the Ping Utility.

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If a client is having trouble getting out to the internet

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or just on the network, our first ping it's default gateway.

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From the Command Line, I simply type ping

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and the IP address of the default gateway,

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192.168.51.1.

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By default, it will issue four pings

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and uses 32 bytes per ping, reporting the latency

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of each ping measured in milliseconds.

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This is also known

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as the round trip time, since it measures how

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long it takes the packet to reach the destination

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and then return.

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When the four pings are complete, statistics

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like how many packets were sent

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and how many returned as well as the minimum maximum

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and average latency for the packets are displayed.

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Sometimes four pings isn't enough to

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troubleshoot intermittent connectivity issues.

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To persistently ping a host, all type ping -t

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and type IP address, 192.168.51.1,

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it will continuously ping showing latency impossible packet

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loss. To end the stream all type Ctrl + C,

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the CLI will spell out complete statistics

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on all the ping sent.

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Say I wanted to ping a host a number

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of times between four and infinity, ping -n allows me

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to specify a total number of pings to be sent.

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Be it 5, 30 or 100. 192.168.51.1.

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To ping an IP, and resolve it to a DNS name.

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I can type ping -a and the host to resolve gregsowell.com.

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The CLI will attempt to resolve the address

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and continue on ping host.

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I can also adjust the size of the packets being sent

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by typing ping -l and the number I'd like it to be.

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This case, I'll say 1,550 192.168.51.1.

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This can be especially useful when

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troubleshooting maximum transmission unit issues.

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The next go-to tool is trace route.

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In windows, the utility is called trace rt.

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Trace route uses ICNP packets

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to map out the path to a destination host.

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For my first trace, I can type in tracert gregsowell.com,

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which has resolved through DNS to 104, 21, 16, 186.

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As it hops through, I may occasionally see an ashtray.

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This means a packet was lost.

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If a hop responds with all asterix,

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this likely means it is blocking ICNP.

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It could also mean that the device is having severe issues.

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On the left.

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I see the hop count, go up as the packets, head

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towards the destination, the amount of latency, IP address

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and DNS name of each hop is also listed.

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Once the destination has been reached

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the CLI prints a trace complete message, or it will count up

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to the default 30 hops and say complete.

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A hop with erratic latency might be indicative

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of an issue or now add the -d flat.

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Tracert -d gregsowell.com.

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This tells trace route

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to skip resolving the names of each hop.

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This can speed up the trace,

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since the client isn't waiting to resolve addresses.

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I'll stop the process with Ctrl + C.

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The -h option,

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lets me change the default max number of hops.

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The last tool is path ping, path ping

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and then the IP address

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in question 192.168.88.1.

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This marries the attributes of both ping and trace route.

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It will do a trace route, then ping each hop for 25 seconds.

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This attempts to give better statistics

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than either a trace route or ping alone.

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It provides the roundtrip time

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as well as the packet loss along the way.

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It has many of the tracert options like -h

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for max number of hops and -n to not resolve DNS names.

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I can also specify -q to adjust the number

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of times it pings each hops.

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I can specify -q to adjust the number

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of times it pings each hop.

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The default is 100.

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All of these tools used in combination

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especially ping and trace route

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are central to troubleshooting network connectivity issues.