PingPlotter Insights

Ruled Out: Non-responding Intermediate Hops

PingPlotter simultaneously runs tests to every hop along the path to your target host. When it detects negative performance at an intermediate hop that is not reflected in the performance in the final target, those issues can often be ruled as part of a problem. For example, if we are receiving 100% of the data from the target but one of the intermediate hops is only sending back 15% of our test data, then the intermediate hop is clearly not treating all data the same. In your case that was just tested, we have determined that several "false negatives" can be ignored.

Solution

Some routers just don't prioritize timed out ICMP requests very high (ICMP requests where the TTL equals 0 after reaching them). If the hop right after consistently performs well, just don't factor this hop into your troubleshooting equation (i.e. ignore it).

In the screenshot above, hop 4 is a great example of this - hop 4 shows packet loss and high latency, but downstream hops (5- 11) look great. Since data getting to hop 5 needs to go through hop 4, this is normal and it's not anything that needs to be chased as a problem. Hop 2 is another example of this.

Another possibility here is that an intermediate hop might use a return route that is different than the hop following (or the final destination). This can mean there is a problem with one return route but not another. Since each hop makes its own decisions about routing, this can definitely happen.

The important thing to remember is that the only thing that really matters is the final destination. If the final hop is showing 0% packet loss and acceptable latency, then all the hops before that can show all kinds of errors. As long as the final destination isn't affected, this is an artifact of router configuration, and there is no problem.

If a particular hop is showing 100% packet loss, it might just not be configured to return packets to the sender when TTL=0 (we rely on this to get information about intermediate hops). Having one or more non-responding intermediate hops is very normal and doesn't indicate there is a problem. If everything else looks good, just ignore those hops.