[CentOS] What can I do to UNDERSTAND why I can't reach centos.org (but everyone else can)?

Fri Mar 1 23:01:35 UTC 2013
Mike Easter <nntp.nym at gmail.com>

Rock wrote:

> For the record, I was unable to get to any of these long-hop destinations:
> $ traceroute tempotv.com.tr ==> died on the 23rd hop
> $ traceroute -I www.centos.org ==> died on the 19th (penultimate) hop
> $ traceroute www.gu.ac.ir ==> Iran, died on the 22nd hop
> $ traceroute www.gu.edu.pk ==> Pakistan, made it only to the 19th hop
> $ traceroute -m 255 www.tourism.gov.my ==> Malaysia died on the 19th hop
>
> All the above died before reaching their destinations.

Your traceroute is UDP.  None of those answer UDP.  All but the last one 
will answer ICMP.

If you use your mtr on them in default ICMP mode, all but the last will 
ICMP traceroute. The last one needs tcptraceroute.

traceroute is not the best tool for some purposes.  All but the last of 
those will ping ICMP.


-- 
Mike Easter