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North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: ingress filtering
>From your vantage point, it seems to work fine. Remember DNS is based on UDP. Packet losses are fairly common. If the reverse doesn't answer fast enough, it will time out and do the reverse via 137. Since IN-ADDR.ARPA is highly delegated, if anyone in the chain is slow, or non-existant, it can take awhile. Timeout = lookup via NetBIOS. Did a packet capture. DNS Request for reverse. DNS Answer. No NetBIOS 137 packets. Sorry dude. Eric At 10:44 AM 5/29/98 -0400, John Fraizer wrote: >At 08:09 AM 5/29/98 -0400, you wrote: >>Actually it has nothing to do with WINS. If all the ISP's would implement >>solid in-addr.arpa reverse mappings, this would go away. Microsoft's DNS >>resolver has been extended, when DNS lookups fail, to do a reverse NETBIOS >>query against the target machine so it can use its name when displaying >>stuff via NBTSTAT, etc. It was designed this way, before the Internet >>became popular. > >The reverse on the name being queried works just fine: > >[OverKill]:/# nslookup www.stefcam.com >Server: NS1.ENTERZONE.NET >Address: 209.41.244.5 > >Name: STEFCAM.COM >Address: 209.41.244.238 >Aliases: www.stefcam.com > >[OverKill]:/# nslookup 209.41.244.238 >Server: NS1.ENTERZONE.NET >Address: 209.41.244.5 > >Name: StefCAM.Com >Address: 209.41.244.238 > > > > >------- >John Fraizer (root) | __ _ | >The System Administrator | / / (_)__ __ ____ __ | The choice >mailto:[email protected] | / /__/ / _ \/ // /\ \/ / | of a GNU >http://www.EnterZone.Net/ | /____/_/_//_/\_,_/ /_/\_\ | Generation > A 486 is a terrible thing to waste... > ============================================================================= Eric Germann Computer and Communications Technologies [email protected] Van Wert, OH 45891 Phone: 419 968 2640 http://www.cctec.com Fax: 419 968 2641 Network Design, Connectivity & System Integration Services A Microsoft Solution Provider
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