I recently downloaded ping plotter 2.3 The first couple of times I was able to see the DNS names of the routers that were pinged. But know, all of a sudden, I cannot see the...all I get Is "---" (no parenthesis). Any suggestions? <img src="/forums/images/icons/confused.gif" alt="" />

Hi.

I'm assuming that you're getting IP addresses for those hops, right? If not, then this answer won't help much with your troubleshooting.

One of the first things you want to do is check to make sure that these hops actually do have reverse DNS lookups assigned to them. To do this, when running a Windows NT/2000/XP environment (I don't have a 9x version handy here, but it may be installed for 9x also, I'm just not sure), you can run the command-line utility "NSLOOKUP" to verify that the IP addresses really do ahve a name assigned to them (or that your computer *thinks* they do).

Open a command prompt and type "NSLOOKUP (ipaddress)" - with the (ipaddress) being the IP shown in the trace. One that I often verify with is 216.92.151.75 - which should resolve to pingplotter.com.

I actually usually start off by entering this IP in Ping Plotter to see if it can reverse-resolve that name, but if it doesn't, you want to move to a non-Ping Plotter application to remove Ping Plotter as a problem.

OK, so let's say you *do not* get a name from this lookup. This could mean that the IP doesn't have a name (in that case, use the pingplotter.com one above to test - as it *should* have a name). If you're not getting names at all, then you'll want to contact the owner of the DNS server you're using (which should be listed when you do the nslookup command) and find out why reverse DNS lookups aren't working.

If you *do* get a name from NSLOOKUP, then it could be that your system doesn't support multi-threaded DNS lookups. This isn't very likely these days, but Windows NT 4.0 had some problems here, and it could be that some replacement DNS services may cause problems here. To test this, go the to Ping Plotter advanced options page ("Edit"->"Advanced Options"), go to the "Packet Options" tab, and turn on the checkbox for "Use non-threaded name lookups". This will make Ping Plotter only do one lookup at a time - which may get rid of your problem (although this will severely impact performance of Ping Plotter traces, so you may want to troubleshoot your system).

So this covers a few possibilities. If this doesn't get you pointed in the right direction, post back here for next steps (along with the results you get from trying the above steps).

- Pete

Here is what I get from my Xp box when I do a nslookup to your Ip..."Cant find server name for address 216.92.151.75
Default servers are not available"
I also have the "use non-threaded name lookup" checked in ping ploter. Just to let you know, this happens also when I try to do a tracert in XP...Is it me thats causing the problem?

This sounds a lot like a problem with your DNS lookups. It's possible they are not configured correctly (via DHCP, or static IP, possibly), but I'm not an expert on resolving DNS lookup issues.

Your first movement on this should probably be to call your provider (your ISP if you're using cable/dsl/dialup, or your network admin if you're going through a business connection) and see if you can get some help on this. It may be that the DNS server that you're getting (through DHCP or manual configuration) isn't valid any more, there may be a failure on that server, or some local configuration problem. The support center for your provider will hopefully have some troubleshooting information and can help with this problem.

Thanks for the help. I think there is a problem with my broadband router. If I just use my modem dns names are shown. But if I put my router back in the loop DNS names are not shown. Anyway...I will work that out on my end. Keep up the good work.(I heard about you on DSLreports.com)