[ale] Can ping but cannot traceroute

Joe Steele joe at madewell.com
Wed Mar 5 14:07:08 EST 2003


To successfully traceroute to www.rational.com, you must use -I (as 
has already been suggested), and you must increase the max_ttl higher 
than traceroute's default.

As shown below, the host would appear to be 34 hops away.  In 
reality, it is only 18 hops away, but because the host is copying the 
TTL from the incoming packets to the outgoing packets, the returning 
packets die before they get back unless our initial TTL is twice the 
distance to the host.  The "!" in the last response is a clue to 
this, as is the missing responses between 17 and 34.  An example of 
this behavior is documented in the traceroute man page.

Unfortunately, none of this answers why you cannot access the website.

--Joe

# traceroute -ieth1 -I www.rational.com -f 5 -m 36 -w 2
traceroute to www.rational.com (129.33.27.206), 36 hops max, 40 byte packets
 5  s8-1-0-9-1.ar1.ATL1.gblx.net (208.51.117.97)  7.987 ms  7.138 ms  7.067 ms
 6  pos2-2-155M.cr2.ATL1.gblx.net (206.132.115.141)  7.018 ms  8.550 ms  6.852 ms
 7  pos1-0-0-155M.br1.ATL1.gblx.net (206.132.115.126)  11.555 ms  13.378 ms  8.583 ms
 8  57.ATM2-0.BR2.ATL5.ALTER.NET (204.255.168.137)  9.058 ms  7.557 ms  8.422 ms
 9  0.so-2-3-0.XL1.ATL5.ALTER.NET (152.63.82.198)  8.534 ms  9.115 ms  9.105 ms
10  0.so-1-2-0.TL1.ATL5.ALTER.NET (152.63.146.6)  8.338 ms  11.384 ms  9.359 ms
11  0.so-3-1-0.TL1.NYC9.ALTER.NET (152.63.10.130)  26.952 ms  26.572 ms  27.184 ms
12  0.so-5-0-0.XL1.NYC9.ALTER.NET (152.63.0.174)  26.953 ms  26.718 ms  27.045 ms
13  0.so-0-0-0.XR1.NYC9.ALTER.NET (152.63.9.57)  27.302 ms  26.730 ms  27.226 ms
14  181.ATM6-0.GW7.NYC9.ALTER.NET (152.63.24.73)  27.801 ms  27.332 ms  27.718 ms
15  ibm-gw2.customer.alter.net (157.130.49.166)  30.659 ms  29.184 ms  29.660 ms
16  * * *
17  129.33.0.76 (129.33.0.76)  32.642 ms  32.993 ms  30.625 ms
18  * * *
19  * * *
20  * * *
21  * * *
22  * * *
23  * * *
24  * * *
25  * * *
26  * * *
27  * * *
28  * * *
29  * * *
30  * * *
31  * * *
32  * * *
33  * * *
34  www.rational.com (129.33.27.206)  31.813 ms !  29.839 ms !  29.941 ms !


-----Original Message-----
From:	Mike Millson [SMTP:mgm at atsga.com]
Sent:	Wednesday, March 05, 2003 8:28 AM
To:	ALE
Subject:	[ale] Can ping but cannot traceroute

I am trying to access the rational site, www.rational.com, and am
getting the "The operation timed out when attempting to connect to
www.rational.com" error. I can ping the site, but when I do a
traceroute, it dies at hop 14 per below. How is it that I am able to
ping the site but not compete a traceroute? Isn't ping UDP, and isn't
UDP routed? Any ideas on what the problem is or how I can troubleshoot
this?

1 adsl-068-157-168-001.sip.asm.bellsouth.net (68.157.168.1) 12.768 ms
12.884 ms 13.004 ms

2 209.149.96.97 (209.149.96.97) 13.265 ms 13.108 ms 13.282 ms

3 209.149.96.142 (209.149.96.142) 13.272 ms 13.115 ms 13.029 ms

4 209.149.96.230 (209.149.96.230) 13.277 ms 19.569 ms 13.279 ms

5 65.83.237.2 (65.83.237.2) 23.382 ms 13.164 ms 13.029 ms

6 pxr00asm-2-0-0.bellsouth.net (65.83.236.2) 13.282 ms 13.041 ms 13.276
ms

7 0.so-0-0-0.GW13.ATL5.ALTER.NET (157.130.73.97) 15.003 ms 13.090 ms
15.000 ms

8 0.so-0-1-0.XL1.ATL5.ALTER.NET (152.63.84.98) 14.842 ms 14.540 ms
14.984 ms

9 0.so-1-2-0.TL1.ATL5.ALTER.NET (152.63.146.6) 14.756 ms 14.576 ms
15.005 ms

10 0.so-3-1-0.TL1.NYC9.ALTER.NET (152.63.10.130) 31.505 ms 31.337 ms
31.508 ms

11 0.so-5-0-0.XL1.NYC9.ALTER.NET (152.63.0.174) 31.512 ms 31.359 ms
31.478 ms

12 0.so-7-0-0.XR1.NYC9.ALTER.NET (152.63.23.138) 31.269 ms 31.330 ms
31.730 ms

13 181.ATM7-0.GW7.NYC9.ALTER.NET (152.63.24.81) 32.544 ms 34.764 ms
34.709 ms

14 ibm-gw2.customer.alter.net (157.130.49.166) 34.721 ms 34.538 ms
34.964 ms

15 * * *

16 * * *

17 * * *

-- 
Thank you,
Mike
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