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

[Nikos Chantziaras]

On 02/09/13 21:17, 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).
>
> I called AT&T and they say the Westell 6100 modem/router I have will
> not respond to pings.  They said I could put it into bridged mode and
> set up PPPoE on the computer connected to it which would cause ICMP
> packets to pass through to the computer.  Would you guys recommend
> that?  For sure I won't attempt this until I'm in the same room as the
> device.

You'll lose the router functionality doing that.  If you need to connect 
other machines to it, then it will only be able to act as a switch, 
meaning that everything you connect to it will either need to be on the 
same subnet, or you need to configure another machine to act as a router 
if you need to connect different subnets.  And the machine will also 
need to be always on in order to provide internet connectivity to other 
machines, since it will be the one that talks to the ADSL modem.

You'll also be losing NAT, which is quite nice for redirecting traffic 
on specific ports to whatever machine you want.  As with the router 
functionality, you will need to configure a Linux machine to do NAT if 
you want to keep having that feature.

There's also the issue of not being able to set up a firewall on the 
router itself anymore.  You can still do that on the target machine 
itself, of course, but there's the issue of creating a firewall on the 
machine you want to protect, which is not optimal (the analogy here 
being that if you want to protect something, you put it behind a wall 
rather than hardening it; even if it's hardened, it still gets hit.)

Or, you might not care about any of the above, in which case using the 
device as a simple ASDL modem (which is what bridging means) will work 
just fine.