2-2 
IPv6 Traceroute 
The traceroute ipv6 command is used to record the route of IPv6 packets from source to destination, 
so as to check whether the link is available and determine the point of failure. 
Figure 2-1 Traceroute process 
 
 
As 
Figure 2-1 shows, the traceroute process is as follows: 
z  The source sends an IP datagram with the Hop Limit of 1. 
z  If the first hop device receiving the datagram reads the Hop Limit of 1, it will discard the packet and 
return an ICMP timeout error message. Thus, the source can get the first device’s address in the 
route.  
z  The source sends a datagram with the Hop Limit of 2 and the second hop device returns an ICMP 
timeout error message. The source gets the second device’s address in the route. 
z  This process continues until the datagram reaches the destination host. As there is no application 
using the UDP port, the destination returns a “port unreachable” ICMP error message. 
z  The source receives the “port unreachable” ICMP error message and understands that the packet 
has reached the destination, and thus determines the route of the packet from source to 
destination. 
Follow these steps to traceroute IPv6: 
To do…  Use the command…  Remarks 
Traceroute IPv6 
tracert ipv6 [ -f first-ttl | -m max-ttl | -p 
port | -q packet-num | -w timeout ]* 
remote-system
 
Required 
Available in any view 
 
IPv6 TFTP 
IPv6 supports Trivial File Transfer Protocol (TFTP). As a client, the device can download files from or 
upload files to a TFTP server. For details about TFTP, see FTP-SFTP-TFTP Operation. 
Configuration preparation 
Enable TFTP on the TFTP server and specify the path to download or upload files. For specific 
operations, refer to TFTP server configuration specifications. 
IPv6 TFTP configuration 
Follow these steps to download or upload files to TFTP servers: