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First, remember that a "ping" is an Internet Control Message Protocol (ICMP) packet. It's a pretty simple as protocols go. ICMP is defined in RFC 792 and provides a way for IP stacks to send simple messages containing information or errors. Given this, it often gets the lowest priority of any protocol on the routing totem-pole, and may actually be rejected by routers if there is a lot of traffic on the network at a given time. To all that, ICMP has been used for scanning, Denial of Service (DoS) attacks, and tunneling thus some providers/markets turned off replies to ping.

Next, pinging the network and trying to correlate packet loss as the cause of your specific problem falls a bit short of the mark. Latency could be a result of the ICMP packets being held while higher priority traffic gets passed. Some devices will even discard ICMPs and give a false positive reading on packet loss. Furthermore, networks are loaded with electronic devices that will experience hiccups (for lack of a better word). That you saw a ping spike or two in a twenty four hour period is probably not an indicator of a problem.

To all that, pinging to a specific interface can give you inconclusive results. You should try to ping through the interface to a known device on the other side. Also, it's not uncommon to see that a ping coming from the ingress side of an interface yields a different result than one coming from the egress side. For example, someone in Middle Georgia, pinging to an interface on the Atlanta network(pinging from egress point)might see packet loss, where someone from Phoenix pinging (ingress)that same interface would see none.

So, what do you do? Well, don't discount packet loss or latency completely. This may indeed be an indicator of a problem with a router or interface. Do post the results of trace routes and ping plots, just remember to further quantify the problem by telling a little bit about what drove you to start trace routing in the first place (i.e. - slow download speeds (under 1 MB), frequent disconnects, modem losing sync, etc.)

Secondly, check all the obvious things -- your cable connections, RWIN settings (see the Tweaks forum here), look at the modem diagnostics if you have access to it, make sure you have all the latest patches for your browser, e-mail, and news client, etc. Check »support.cox.net for details on technical problems and service configuration.

If you're an online gamer, check the gaming forum here. Lots of pros to help you ensure your game and PC configurations are correct, and that you get the most out of the experience.

Also remember that the more info you can provide about your problem in the post, the easier it will be for other participants and tech support to assist in getting your problem resolved.

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by PapaSmurf See Profile
last modified: 2002-06-18 19:38:41