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On 01/09/2013 17:04, Grant wrote: |
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>>>>>> My laptop can't ping my remote system but it can ping others |
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>>>>>> (google.com, yahoo.com, etc). I've tried disabling my firewall on |
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>>>>>> both ends with '/etc/init.d/shorewall stop && shorewall clear'. Could |
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>>>>>> my AT&T business ADSL connection on the remote system be blocking |
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>>>>>> inbound pings? |
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>>>>>> |
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>>>>> Possible, have you tried pinging your remote system from a different |
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>>>>> location? You may try http://www.downforeveryoneorjustme.com/ |
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>>>> |
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>>>> Sorry, wrong link: http://ping.eu/ping/ |
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>>> |
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>>> I get 100% packet loss when pinging from there. |
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>> |
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>> try an icmp traceroute, if you are lucky you'll get a result that tells |
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>> you on which hop the pings cease to work: |
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>> |
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>> traceroute -I |
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>> |
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>> but do read the man page (traceroute is like ps in that there are many |
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>> versions around and options don't always match up with what folk say on |
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>> mailing lists) |
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> |
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> I did 'traceroute -w 30 -I ip-address' several times and the last IP |
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> displayed is always the same. I looked it up and it's an AT&T IP |
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> supposedly located about 1500 miles from my machine which is also on |
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> an AT&T connection. Does this tell me anything? |
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Yes, it tells you that all hops up to that point at least respond to |
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the kinds of icmp packets traceroute uses. The first hop that fails to |
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answer isn't answering. |
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You are looking for possible reasons why icmp might not be working out |
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properly - that router is your first suspect. Admittedly, it might be |
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blocking traceroute pings and still allow the responses you seek, but |
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you have to start somewhere :-) |
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The problem you are trying to track down is notoriously tricky to nail |
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down exactly as too many ISPs out there obsessively block useful icmp |
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traffic. They believe it's security. I believe it's security theatre and |
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makes fault finding on a live network infernally difficult. |
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Mick is on the right track - deal with each issue one by one till you |
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hit paydirt. |
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-- |
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Alan McKinnon |
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alan.mckinnon@×××××.com |
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