Ask the Expert

IMPORTANT MODERATION NOTICE

This community is currently under full moderation, meaning  all posts will be reviewed before appearing in the community. Please expect a brief delay—there is no need to post multiple times. If your post is rejected, you'll receive an email outlining the reason(s). We've implemented full moderation to control spam. Thank you for your patience and participation.

  • 1.  What is the best way to identify whether my ISP can reach the network I need to reach ?

    Posted 05-03-2021 05:34
    If I like to reach 192.168.0.2 via ISP which does not provide my any information except the its peer IP with me, how can I identify whether 192.168.0.2 is reachable from ISP ?

    I did the following, and some time I got the Destination unreachable from the ISP, so I can tell the destination I like to reach is unreachable from ISP.
    [edit]
    root@Branch1# run traceroute 192.168.0.2 no-resolve
    traceroute to 192.168.0.2 (192.168.0.2), 30 hops max, 40 byte packets
     1  172.16.1.6  5.590 ms !N  2.315 ms !N  1.855 ms !N
    ​

    But sometimes for some reason, just nothing returns.  just like the following

    root@Branch1# run traceroute 192.168.0.2 no-resolve
    traceroute to 192.168.0.2 (192.168.0.2), 30 hops max, 40 byte packets
    

    Any other way can help to identify the issue is on my side, or on ISP side ?

    thanks !!



  • 2.  RE: What is the best way to identify whether my ISP can reach the network I need to reach ?

     
    Posted 05-03-2021 05:38
    The address 192.168.0.2 is NOT allowed to route on the internet.  This is part of one of the prefixes reserved in rfc 1918 for internal private networks only.
    192.168.0.0/16
    10.0.0.0/8
    172.16.0.0/12

    These address ranges are private ip addresses usable only inside non-internet routed networks.

    ------------------------------
    Steve Puluka BSEET - Juniper Ambassador
    IP Architect - DQE Communications Pittsburgh, PA (Metro Ethernet & ISP)
    http://puluka.com/home
    ------------------------------



  • 3.  RE: What is the best way to identify whether my ISP can reach the network I need to reach ?

    Posted 05-04-2021 18:23
    100% agreed with Steve!
    with that in mind I believe the IPs represented on this thread are selected randomly for lab purposes. This issue is tracked  here as well.


  • 4.  RE: What is the best way to identify whether my ISP can reach the network I need to reach ?

    Posted 05-05-2021 16:29
    thanks a lot !!

    The first time I posted, I did not see my post, so I posted it again. That is why duplicated.


  • 5.  RE: What is the best way to identify whether my ISP can reach the network I need to reach ?

    Posted 05-05-2021 16:30
    thanks a lot !!


  • 6.  RE: What is the best way to identify whether my ISP can reach the network I need to reach ?

    Posted 05-05-2021 16:29
    Networks that make up "the internet" do not exchange, therefore route, RFC1918 addresses between them.  These are reserved routes for private/internal use, so it's expected behavior that when performing a traceroute from your network outbound to the internet that it would fail.