Networking/international hosted pings and traceroutes

I am working on a project involving correlations in distance of the server in relation to pings and traceroutes. So I am getting the number of hops and the average ping time for different web sites. I am using puTTy and unix code to achie开发者_StackOverflow社区ve this, when I traceroute the website (traceroute australia.gov.au -m 255) I allow for the maximum number of hops. I get about 18 hops, and then i get 237 numbers with three asterisks next to them. At first I assumed that this was a result of the -m 255 extension to the command, but it doesn't occur with websites like youtube or google. Is this timed out hops/connections? Also when i ping this website (ping australia.gov.au -c 25), I get no respsonse for about a minute (near 2000ms) and then the print out says that 25 packets were sent and 0 were received, what is the explanation for this?

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Lots of places all over the internet block ICMP, meaning that australia.gov.au might have a valid routable IP, but just doesn't send back echo reply.

Three asterisks line from traceroute, as far as I can remember, means a packet with given TTL did not get a reply. That again probably indicates that the host/router does not want to be bothered replying to arbitrary ICMP and/or UDP packets.