[plug] no route to host(s), but can ping?

[Lucas van Staden]

Daniel Pittman wrote:
> Lucas van Staden <lvs at dedmeet.com> writes:
>
>   
>> Just can't figure this out, and I am sure I am missing something
>> obvious here.
>>     
>
> You missed a firewall, or a lack of IPv6, somewhere in there. :)
>
>   
>> Box is debian hardy 8.04
>> Can for example ping www.google.com:
>>
>> PING www.l.google.com (66.249.89.104) 56(84) bytes of data.
>> 64 bytes from jp-in-f104.google.com (66.249.89.104): icmp_seq=1 ttl=244
>> time=276 ms
>>     
>
> So, ICMP echo messages get through, but...
>
>   
>> but cannot traceroute: (unknown host?)
>>
>> --- www.l.google.com ping statistics ---
>> 2 packets transmitted, 1 received, 50% packet loss, time 1004ms
>> rtt min/avg/max/mdev = 276.041/276.041/276.041/0.000 ms
>> web at webserver ~ $ sudo traceroute6 www.google.com
>> traceroute: unknown host www.google.com
>>     
>
> ...and you sure you meant to use IPv6 rather than IPv4 in the trackroute?
>   

Nope, I meant to use IPv4. Knew it was something staring me in the face....
Did not notice (using tab-autocomplete) that traceroute6 was used.
Installed traceroute (IPv4) and now trace works.

traceroute to www.google.com (66.249.89.99), 30 hops max, 40 byte packets
1 ACA80001.ipt.aol.com (172.168.0.1) 2.060 ms 3.112 ms 3.413 ms
2 nexthop.wa.ii.net (203.59.14.16) 21.184 ms 22.035 ms 24.187 ms
3 gi2-7.per-qv1-bdr2.ii.net (203.215.4.87) 25.466 ms 26.720 ms 27.794 ms
4 gi0-15-1-1.syd-stl-core1.ii.net (203.215.20.66) 86.781 ms 89.287
etc etc....

Thank you.


>   
>> Found that my smtp server stopped sending mail, with error 'no route to host'
>>
>> 2008-11-28 11:21:51 1L5szN-0003qk-OM aspmx.l.google.com [209.85.163.27] No
>> route to host
>>     
>
> [...]
>
>   
>> Same issue, I can ping those, but I cannot traceroute.
>> I can access internet, downloads etc fine from the box.
>>
>> Any Ideas what I am missing here? Or what to look at?
>>     
>
> Well, my first check would be if IPv4 traceroute worked, but it might
> not.  You might also check if 'tcptraceroute' can connect, or where it
> tells you that the connection is blocked.
>
> However, my guess would be that a firewall on your system, or at your
> ISP, is preventing the communication.
>   
Now that I am not hunting down the wrong track, I checked my ISP 
(iinet), and yep, port blocking was toggled on.
Toggled to off.
Also changed my ips to correct private range from 172.168. to 172.16. 
(never noticed the sneaky 8 in the ip, until now.)

Figure it was the port blocking that was the main issue, but at least 
this showed me my private IP range was wrong.

All my test emails just got delivered, so problem solved.

Thanks for all the pointers from all.

-Lucas




> Regards,
>         Daniel
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