DCC digest, Vol 1 #1007 - 1 msg

William Taylor williamt@napanet.net
Tue Apr 22 13:13:30 UTC 2008


Vernon Schryver wrote:
>> From: William Taylor <williamt@napanet.net>
>>     
>
>   
>> I am having the same sort of problem. dcc just stops working all of a 
>> sudden. Can't figure out why
>>
>> r 21 21:18:26 lds dccifd[9887]: continue not asking DCC 3 seconds after 
>> failure
>>     
>
> What is it that stops working, the shell script updatedcc or the
> daemon dccifd's access to the public DCC servers?
>
>
>   
>> I manually upgrade to the latest version and that didn't help. I did a 
>> tcpdump from my local machine and from one of the public mirrors I have 
>> access to and I see traffic getting there and back. Just things aren't 
>> working.
>> Any ideas?
>>     
>
> There are two common causes for not getting DCC results:
>
>   1. a firewall that blocks responses sent by the servers from their
>       UPD port 627 to the DCC client (e.g. dccifd).
>
>   2. triggering the DoS defenses of the public DCC servers by sending
>       too many requests, most often because of the use of the 3+ year
>       old version of the client code redistributed by Linux repackagers.
>
> You can check to see whether your DCC client code can hear the public
> servers with `cdcc info`.  If they can't, there will be complaints about
> "not answering" for all of the dozen servers that your client is trying
> to use.
>
>
> Judging from counts on three of the servers, a client at 206.81.96.54
> is sending a few requests and NOPs typical of small tests.
>
> 206.81.97.109 is also currently (April 22, 06:30 UTC) making a few tests.
>
> A client at  206.81.96.33 has sent somewhat more than 2000 requests and
> perhaps 1000 NOPs.  It is using version #8 of the DCC client-server
> protocol, which implies that it is not use ancient version.  Its last
> request was at 02:08:40, and since then has probably sent only NOPs.
> My guess is that a firewall of some sort has been blocking responses
> from UDP port 6277 from at least 64.124.52.0/24 and 209.169.14.0/24 to
> dccifd at 206.81.96.33 from about 02:10 UTC.
>
>
> Vernon Schryver    vjs@rhyolite.com
> _______________________________________________
> DCC mailing list      DCC@rhyolite.com
> http://www.rhyolite.com/mailman/listinfo/dcc
>
>   
Last night I was guessing that I was sending to my requests out from 
206.81.96.33 and things were getting autoblocked.
I installed a temp server at 206.81.96.54 which seemed to make the dcc 
client happy again. I also added rules this morning
for the firewall stuff on .33. 206.81.97.109 is a colo customer running 
their own mailserver.
BTW I ordered the new server for the mirror yesterday so that should be 
here soon.
Do I need to have an official server-id for 206.81.96.54?

Thanks,
  William




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