Re: [gentoo-user] Can't ping remote system

[Mick]

On Sunday 01 Sep 2013 19:50:53 Grant wrote:

> >> So the culprit is the first IP that should appear in the list but
> >> doesn't?  If so, how is that helpful since it's not displayed?
> >
> > This is where it gets tricky. You identify the last router in the list
> > for which you have an address or name, and contact the NOC team for that
> > organization. Ask them for the next hop in routing for the destination
> > address you are trying to ping and hope that they will be kind enough to
> > help you out.
>
> Oh man that's funny.  Really?  Let's say they do pass along the info.
> Then I hunt down contact info for the culprit router based on its IP
> and tell them their stuff isn't working and hope they fix it?
> Actually, since the last IP displayed is from AT&T and my server's ISP
> is AT&T, I suppose it's extremely likely that the culprit is either an
> AT&T router somewhere or my own server and I could find out by calling
> AT&T.

It could well be your router and it is easy to confirm this after you set it 
up to respond to ping (or set it to forward all packets with ICMP protocol to 
your server while you're troubleshooting this).

After you set up your router/server to respond you should be getting a 
different mtr or traceroute output showing any hops in between you and your 
server that are dropping packets.  You may have to contact them if they are 
running a saturated link which is not allowing you to use the service you are 
paying them for.  Here's an example of saturated links:

# mtr -r -c 9 -n bbc.co.uk
Start: Sun Sep  1 20:03:24 2013
HOST: dell_xps                    Loss%   Snt   Last   Avg  Best  Wrst StDev
[snip ...]

  4.|-- 195.66.224.103             0.0%     9   65.8  41.1  26.0  77.3  19.1
  5.|-- ???                       100.0     9    0.0   0.0   0.0   0.0   0.0
  6.|-- ???                       100.0     9    0.0   0.0   0.0   0.0   0.0
  7.|-- 132.185.254.109            0.0%     9   28.1  32.5  27.0  55.7   9.7
  8.|-- 132.185.255.140            0.0%     9   27.0  27.5  26.4  29.0   0.6
  9.|-- 212.58.251.195             0.0%     9   27.5  28.0  27.1  28.9   0.4


-- 
Regards,
Mick