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Catalyst 6500 Series Switch Command Reference—Release7.6
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Chapter2 Catalyst 6500 Series Switch and ROM Monitor Commands traceroute
Table 2 -105 describes the fields in the traceroute command output.
If traceroute receives an ICMP err or m essag e ot he r t han a time- e xc eeded o r p ort- unr eacha bl e mes sage,
it prints one of the error codes shown in Table 2-106 instead of the round-trip time or an asterisk (*).
Related Commands ping
Table2-105 traceroute Command Output Fields
Field Description
30 hops max, 40 byte
packets Maximum TTL value and the size of the ICMP datagrams being sent.
2 ms 1 ms 1 ms Total time (in milliseconds) for each ICMP datagram to reach the
router or host plus the time it took for the ICMP time-exceeded
message to return to the host.
An exclamation point following any of these values (for example,
20 ms !) indicates that the port-unreachable message returned by the
destination had a TTL of 0 or 1. Typically, this occurs when the
destination uses the TTL value from the arriving datagram as the
TTL in its ICMP reply. The reply does not arrive at the source until
the destination receives a traceroute datagram with a TTL equal to
the number of hops between the source and destination.
3 ms * 2 ms “*” indicates that the timeout period (default of 5 seconds) expired
before an ICMP time-exceeded message was received for the
datagram.
Table2-106 traceroute Error Messages
ICMP Error Code Meaning
!N No route to host. The network is unreachable.
!H No route to host. The host is unreachable.
!P Connection refus ed. T he p rot oco l i s u nre ach able .
!F Fragmentation needed but do not fragment (DF) bit was set.
!S Source route failed.
!A Communication administratively prohibited.
? Unknown error occurred.