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I'm tracing a path to my server using tcptraceroute. The server is showing intermittent network availability. It's as if some packets get through fine, others take a long time and some never get there.

Here are two tcptraceroute's to the server. Any idea what would cause such varying output? or any suggestions on how to futher debug this problem?

 1  VLAN host (<VLAN IP>)  0.786 ms 1.250 ms  1.637 ms  
 2  * * *  
 3  server host (<serverIP>)  0.632 ms 0.646 ms  0.647 ms

and

1  VLAN host (<VLAN IP>)  0.848 ms  1.259 ms  1.682 ms
 2  * * *
 3  * * *
 4  * * *
 5  * * *
 6  * * *
 7  * * *
 8  * * *
 9  * * *
10  * * *
11  * * *
12  * * server host (<serverIP>)  0.615 ms
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1 Answer 1

up vote 1 down vote accepted

Are these traces originating from the same host?

The last hop (the server) is responding pretty much the same in both traces so I don't see any problem there. The hops in between the first and last hops can be ignored for the most part as those are traces to those particular hosts and are not generally indicitive of a problem. the devices that don't respond are either firewalled or are ignoring your ICMP echo request, which is perfectly normal and aceptable.

Any type of trace route test is useful in determining the path to a particular host or network but is not generally useful in determining the quality of that path.

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The traces are originating from the same host. Do you have a suggestion for testing quality of the path? Thanks –  kobrien Jun 27 '11 at 12:58
    
Issue resolved. The webservers keepalive was set too high. Traceroute was not indicating a fault. –  kobrien Jun 27 '11 at 16:30
    
Glad you got it sorted out. –  joeqwerty Jun 27 '11 at 16:48

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