If a hop has a bell icon next to it, this means that hop is being monitored for an alert ( alerts are covered in the advanced settings section of this tutorial). This will focus the upper graph on that period you double-clicked (we cover this topic in a bit more detail below).ġ - The number of hops that device in the route is from your computer. By default, you're looking at the most recently collected samples - but you can also focus on samples that are not the most recent samples by double-clicking on the time graph. The lower horizontal graph is called Timeline Graph.Īll numbers on the trace graph use the " Focus" setting to control how many samples are used in the calculations. All columns on the trace graph are re-sizable. The upper graph is called the Trace Graph. Please refer to the below image (annotated with numbers) that we've saved from PingPlotter ("File" -> "Save Image"), and the explanations (referencing the numbers) below the graphs. The first two (Trace Grid and Graph) are referred to primarily as the Trace Graph, as they are used together. There are actually three discreet areas: the Trace Data Grid, the Trace Graph and the Timeline Graph. At a glance, you're able to visually see where a problem lies. The ISP eventually found the duplicate blocks and apologized.The graphs are where PingPlotter really shines. After the ISP swore up and down for a week that he had no routing problem we were finally able to convince him to go router-by-router and check if he hadn't allocated overlapping IP blocks. The problem was eventually resolved to a duplicate IP address block allocation that caused packets from a BGP router to sometimes return to the customers network and sometimes not. So over the course of two frustrating weeks I went through all of the above steps and solved the problem.Ī similar problem at a customer of mine was not resolved by the above eight steps. It turns out that the telco had upgraded line card modulation to handle higher DSL speeds and had not informed subscribers in the area that the older modems might have problems. I changed the telco supplied D-Link DSL 2500U to a newer Edimax DSL/Wireless switch. The ISP tech said he saw a lot of re-login attempts from the DSL router. The telco found no problem with the line. I recently had a similar problem in my office. Replace the modem with a different model or brand that handles higher speeds. Replace the DSL filter and the filter-to-modem wire between the phone and the modem. This will eliminate routing errors or other network errors at your ISP.Ĭall your ISP and ask their tech support if they are seeing an unusual number of re-login attempts from your modem.Ĭall your telephone supplier (if different from the ISP) and ask to do a line condition test (might take a few hours). If you are using a DSL modem, test with ping against your ISP's nameserver hosts, or if you can log into your DSL modem and see the default gateway, ping the default gateway. Verify that there is no packet loss between two computers on the same wired or wireless local network (in your home or office or wherever the problem is). Verify that the problem is not with the current host - change the computer from which you are testing and change the network cables to the router or modem and retest. Verify that there is no packet loss on pings between your computer and the router or DSL modem itself. Here are the steps, from nearest the host to farthest away: You need to take steps to isolate the problem.
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