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New Member

Different traceroute results from different networks - Why?

I am having an interesting thing happening that I cannot figure out. I am attempting to traceroute to 216.52.55.28 from three different ISP's. I get different results depending on the different ISPs. The first two traceroutes stop 2-hops short of the destination. The last traceroute finds its way to the destination. All routes go through a set of routers that are load balancing that are two hops away from the final destination. Why would the first two fail but the last go through when all three make it to the last set of routers two hops away from the destination? It seems like 63.251.131.249 isn't sending an ICMP Time Exceeded message to the first two devices performing the traceroute, but it is on the last one. WHY?!?!

routera# traceroute 216.52.55.28

Type escape sequence to abort.

Tracing the route to 216.52.55.28

1  76.114.8.1 10 msec 20 msec 10 msec

2  68.85.120.165 10 msec 10 msec 0 msec

3  68.87.202.241 20 msec 10 msec 20 msec

4  68.86.94.113 30 msec

    68.86.93.113 20 msec 30 msec

5  77.67.70.181 20 msec 20 msec 20 msec

6  141.136.109.138 90 msec 90 msec 90 msec

7  77.67.77.54 100 msec 90 msec 90 msec

8  63.251.128.41 90 msec

    63.251.128.104 90 msec 90 msec

9   *  *  *

10  *  *  *

11  *  *  *

12  *  *  *

13  *  *  *

14  *  *  *

15  *  *  *

16  *  *  *

17  *  *  *

18  *  *  *

19  *  *  *

20  *  *  *

routerb#traceroute 216.52.55.28

Type escape sequence to abort.

Tracing the route to 216.52.55.28

VRF info: (vrf in name/id, vrf out name/id)

  1 65.113.96.177 [AS 209] 8 msec 4 msec 4 msec

  2 67.14.30.126 [AS 14051] 80 msec 80 msec 80 msec

  3 65.120.117.250 [AS 209] 84 msec 84 msec 88 msec

  4 63.251.128.41 [AS 14742] 84 msec

    63.251.128.104 [AS 14742] 84 msec

    63.251.128.41 [AS 14742] 80 msec

  5  *  *  *

  6  *  *  *

  7  *  *  *

  8  *  *  *

  9  *  *  *

10  *  *  *

11  *  *  *

12  *  *  *

13  *  *  *

14  *  *  *

15  *  *  *

16  *  *  *

17  *  *  *

18  *  *  *

19  *  *  *

20  *  *  *

Trace to private.chartconnect.com from routerc


1 - 172.26.96.161 71.8ms 88.8ms 91.0ms
2 - 172.26.96.1 94.3ms 91.4ms 85.6ms
3 - 172.16.126.36 88.9ms 83.5ms 82.1ms
4 - 12.249.2.49 98.2ms 89.0ms 79.5ms
5 - 12.83.180.82
6 - 12.122.81.73 sffca01jt.ip.att.net
7 - 64.125.12.117 99.7ms 94.5ms 94.3ms
8 - 64.125.24.5 xe-4-0-0.cr2.sjc2.us.above.net 81.9ms 83.9ms 79.7ms
9 - 64.125.26.142 ae3.cr2.ord2.us.above.net 149ms 138ms 140ms
10 - 64.125.28.233 ae5.cr1.ord2.us.above.net 139ms 147ms 144ms
11 - 64.125.24.33 ae6.cr1.lga5.us.above.net 160ms 155ms 149ms
12 - 64.125.25.41 xe-1-1-0.mpr3.bos2.us.above.net 163ms 171ms 190ms
13 - 208.184.110.70 208.184.110.70.IPYX-072053-002-ZYO.above.net 179ms 166ms 171ms
14 - 63.251.128.104 border11.te8-1-bbnet2.bsn.pnap.net 178ms 176ms 174ms
15 - 63.251.131.249 161ms 166ms 160ms
16 - 216.52.55.28 private.chartconnect.com 159ms 158ms 155ms

1 ACCEPTED SOLUTION

Accepted Solutions
New Member

Different traceroute results from different networks - Why?

I figured out my own issue. I wasn't aware that different OS's implement traceroute differently. As I'm sure at least some of you are aware, and I just learned, unix-like operating systems, including Cisco IOS, use UDP datagrams addressed to an unused port, while Windows and other OS's use ICMP type 8 packets. I believed all used ICMP type 8 packets. So the ultimate problem is there is a firewall or ACL that is blocking the UDP traffic, but allowing the ICMP traffic through.

Case closed.

1 REPLY
New Member

Different traceroute results from different networks - Why?

I figured out my own issue. I wasn't aware that different OS's implement traceroute differently. As I'm sure at least some of you are aware, and I just learned, unix-like operating systems, including Cisco IOS, use UDP datagrams addressed to an unused port, while Windows and other OS's use ICMP type 8 packets. I believed all used ICMP type 8 packets. So the ultimate problem is there is a firewall or ACL that is blocking the UDP traffic, but allowing the ICMP traffic through.

Case closed.

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