Why can't I traceroute?

This is a problem with your router, for sure.

You can tell that because you get a response from your router (192.168.0.1) but no response from anything beyond that.

Typically this means the router is blocking the UDP traffic that traceroute uses by default.

The solution is to use IMCP traces rather than UDP traces (ICMP is also the default in Windows which explains why your PC can perform the trace).

To run a ICMP trace, add the -I switch:

traceroute -I www.apple.com

Ping speed is good. Traceroute is bad and the internet is extremely slow after I get past the socal.rr servers. Very frustrating. Have had Time Warner cable to the house 4 times and Earthlink is not helpful at all.

Mark

Either your router is blocking the receipt of the packets from the other side, or the server which would normally appear for a specific entry doesn't send a response packet when probed, or it sends a message but it doesn't reach you because the maximum number of hops that packet will take isn't enough to make the return journey. For more information, see the traceroute manual page.

(40296)

I don't see why calling Time Warner out to the house is going to make any difference.

internet is extremely slow after I get past the socal.rr servers

This means that it's not your connection to socal.rr.com and that's the only part of the link that an on-site tech can affect. If the problem is on the other side of the socal.rr.com servers then the problem is either with socal.rr.com or, maybe, with your MTU (which might explain why ping is good but larger transfers are slow).

The only thing I'd try would be lowering the MTU on your network, but it's a bit of a long shot.

http://support.apple.com/kb/HT2532

I'd try 1492, 1460 and 1400 as trial numbers to see if it makes any difference.

Camelot,

Here is a recent transcription of my grinding traceroute initiated to www.apple.com:

Traceroute has started ...

traceroute to www.apple.com.akadns.net (17.251.200.32), 64 hops max, 40 byte packets
1 192.168.1.1 (192.168.1.1) 2.323 ms 1.588 ms 1.563 ms
2 user-0can6g1.cable.mindspring.com (24.171.154.1) 13.447 ms 14.981 ms 18.995 ms
3 ge-11-0-4.stclca2-rtr1.socal.rr.com (66.75.145.89) 15.176 ms 34.421 ms 11.804 ms
4 ae9.chswca1-rtr1.socal.rr.com (66.75.145.42) 30.583 ms 21.694 ms 48.224 ms
5 tge4-0-1.lsanca4-rtr1.socal.rr.com (66.75.145.11) 33.041 ms 16.707 ms 16.623 ms
6 ae10.tustca1-rtr1.socal.rr.com (66.75.161.48) 40.469 ms 34.191 ms 76.450 ms
7 te-1-3.car1.tustin1.level3.net (4.79.140.37) 56.219 ms te-1-4.car1.tustin1.level3.net (4.79.140.1) 31.212 ms 42.360 ms
8 ae-2-3.bar1.tustin1.level3.net (4.69.132.218) 24.679 ms 37.851 ms 111.543 ms
9 ae-6-6.ebr1.losangeles1.level3.net (4.69.136.202) 35.016 ms 40.628 ms 50.993 ms
10 4.69.137.14 (4.69.137.14) 41.029 ms 28.702 ms 41.261 ms
11 ae-93-93.ebr3.losangeles1.level3.net (4.69.137.45) 28.583 ms 59.908 ms 24.289 ms
12 ae-2.ebr3.sanjose1.level3.net (4.69.132.9) 52.258 ms 33.900 ms 46.636 ms
13 ae-63-63.csw1.sanjose1.level3.net (4.69.134.226) 47.483 ms 60.544 ms 33.615 ms
14 ae-21-69.car1.sanjose2.level3.net (4.68.18.11) 48.060 ms 32.764 ms 29.345 ms
15 apple-compu.car1.sanjose2.level3.net (4.79.60.6) 47.824 ms 26.186 ms 41.428 ms
16 * * *
17 * * *
18 * * *
19 * * *
20 * * *
21 * * *
22 * * *
23 * * *
24 * * *
25 * * *
26 * * *
27 * * *
28 * *

Here is a recent transcription of my grinding traceroute initiated to www.apple.com:
...
15 apple-compu.car1.sanjose2.level3.net (4.79.60.6) 47.824 ms 26.186 ms 41.428 ms
16 * * *

This is a completely different problem from the original post.

In the original post, the local router was not passing the traffic.

In this case it's the remote router (or firewall) that's blocking the traffic. You're getting a pretty clean trace up to Apple's network, but Apple are not allowing the traceroute traffic into their network, instead blocking it at the edge (hop 16 in this trace).

Therefore this proves that traceroute is working as expected.

Thanks for your expertise. This has only been happening for about a month now and my internet connection is now only about 2 times faster than dial-up with a PING Download speed of 9700 and and Upload speed of 948. Any suggestions?

Thanks,
Mark

Does a traceroute change when you switch DNS servers?

Generally, no, although there are cases where it could, especially for large/global sites - for example if you switch from using a DNS server at your ISP in LA to using a DNS server in, say, Paris then it's likely you'd get routed to a server in Europe because the site has configured their network to route European users to a Europe-based server and US users to a US-based server, and the way that's typically done is by populating the DNS table with different values depending on where the request comes from.

It doesn't even have to be such a broad geographic distance. For example if I lookup www.google.com from here in San Jose, CA I get 74.125.45.99. If I perform the same lookup from a server in Houston, TX I get 64.233.169.99. Clearly google are optimizing their network so that someone that appears to be in Texas (because they're using a DNS server in Texas) gets routed to a nearby datacenter, whereas a user in CA gets routed to a CA-based datacenter.
FWIW I get a difference of about 30ms on a ping to the two different servers.

I also am confused over the difference between changing the DNS servers on my router vs. in my OS. What happens if I change one and not the other?

Absolutely nothing. The server setting in the router is only used by lookups performed by the router itself (e.g. if you were using it's admin interface to perform a trace or lookup). If your machine is using some other DNS server (e.g. one provided by your ISP) then it doesn't matter what the router is using.
The only exception to this is if your router is running as a DHCP server and it's telling clients to use whatever DNS server it is configured with, then the router would push that server address to the clients.

I'm not sure what you mean by 'PING download speed'.

Ping is not a valid measurement of download speed. It is a reasonable approximation of latency (delay between you and server) but in no way reflects how fast you can download data from (or upload data to) the server.

Sorry, my ignorance is showing!

I tested my internet speed at www.speakeasy.net. Those speeds are consistent and good. When I PING www.apple.com, I get only "Ping has started ...

PING www.apple.com.akadns.net (17.251.200.32): 56 data bytes

--- www.apple.com.akadns.net ping statistics ---
50 packets transmitted, 0 packets received, 100% packet loss"

When I PING www.earthlink.net using the Network Utility, my results are as follows:

Ping has started ...

PING www.earthlink.net (207.217.125.165): 56 data bytes
64 bytes from 207.217.125.165: icmp_seq=0 ttl=236 time=57.484 ms
64 bytes from 207.217.125.165: icmp_seq=1 ttl=236 time=57.416 ms
64 bytes from 207.217.125.165: icmp_seq=2 ttl=236 time=57.210 ms
64 bytes from 207.217.125.165: icmp_seq=3 ttl=236 time=56.457 ms
64 bytes from 207.217.125.165: icmp_seq=4 ttl=236 time=58.272 ms
64 bytes from 207.217.125.165: icmp_seq=5 ttl=236 time=60.259 ms
64 bytes from 207.217.125.165: icmp_seq=6 ttl=236 time=58.573 ms
64 bytes from 207.217.125.165: icmp_seq=7 ttl=236 time=59.437 ms
64 bytes from 207.217.125.165: icmp_seq=8 ttl=236 time=58.050 ms
64 bytes from 207.217.125.165: icmp_seq=9 ttl=236 time=66.726 ms
64 bytes from 207.217.125.165: icmp_seq=10 ttl=236 time=57.541 ms
64 bytes from 207.217.125.165: icmp_seq=11 ttl=236 time=58.435 ms
64 bytes from 207.217.125.165: icmp_seq=12 ttl=236 time=60.545 ms
64 bytes from 207.217.125.165: icmp_seq=13 ttl=236 time=82.356 ms
64 bytes from 207.217.125.165: icmp_seq=14 ttl=236 time=70.891 ms
64 bytes from 207.217.125.165: icmp_seq=15 ttl=236 time=59.740 ms
64 bytes from 207.217.125.165: icmp_seq=16 ttl=236 time=58.421 ms
64 bytes from 207.217.125.165: icmp_seq=17 ttl=236 time=68.825 ms
64 bytes from 207.217.125.165: icmp_seq=18 ttl=236 time=86.811 ms
64 bytes from 207.217.125.165: icmp_seq=19 ttl=236 time=58.647 ms
64 bytes from 207.217.125.165: icmp_seq=20 ttl=236 time=69.229 ms
64 bytes from 207.217.125.165: icmp_seq=21 ttl=236 time=58.890 ms
64 bytes from 207.217.125.165: icmp_seq=22 ttl=236 time=56.547 ms
64 bytes from 207.217.125.165: icmp_seq=23 ttl=236 time=58.935 ms

I have been having the same issues with my traceroute. However, I test my PC directly connected to the cable modem with no issues. Mac stalls almost everytime.

Mark

Hello Pianoman,

I am a professional musician myself and are having the same issues you are having. Is this a recent problem? Mine is about a month old now.

Mark LeVang