At 11:26 AM +0000 6/24/03, ericbrouwers wrote: >Is NetBIOS a protocol in the sense of ISO's OSI definition??
Not necessarily for ISO, but see RFC 1001 and 1002 for the IETF definition. > I never really >checked it. Originally it was a programming interface on IBM PCs. I did some >network programming with NetBIOS back in 1989... yes, old man... > >When I started reading commercial Cisco certification books, the authors >sometimes tried to convince me that it is a protocol....Whatever, I'm not >going to >give a formal answer, but for those interested maybe give the following a >try. It's from IBM's TCP/IP Tutorial and Technical Overview, October 1998, >one of their famous redbooks (http://www.redbooks.ibm.com): > >"... >NetBIOS is a vendor-independant software interface (API), not a protocol. >There is no official NetBIOS specification, although in practice, the >NetBIOS version described in the IBM publication SC30-3587 LAN Technical >Reference: 802.2 and NetBIOS APIs is used as reference. >.." > >Have fun! >:-) >Eric Brouwers > >----- Original Message ----- >From: "Priscilla Oppenheimer" >To: >Sent: Tuesday, June 24, 2003 3:50 AM >Subject: Re: netbios [7:71084] > > >> - jvd wrote: >> > >> > OT: >> > hi, i just have to say that i will never try to answer anything >> > on this forum again. :-) >> >> Well, would that be Grumpy, Bashful, Sleepy, or Dopey to do that? :-) >> Seriously, you should keep answering. You have sent some great answers, >but >> you don't want to keep insisting something when replying to my messages. >It >> makes me very Grumpy and I'm not Bashful when wielding a keyboard (just in >> person). I know lots of books claim that NetBIOS isn't routable, but I bet >> those exact same books also classify it as a session-layer protocol. And >it >> does make a good example of a session-layer protocol. One of the few that >we >> have! And if it runs at that layer, then it is routable. I think even IBM >> said it was a session-layer protocol in some of their early documents, >which >> unfortunately, I recently tossed. >> >> Directed broadcasts came from out of the blue. I really don't think >Windows >> networking uses them, although maybe it does. Was the comment maybe in >> reference to the helper address suggestion that I made? You can tell a >> router to send the packets when "it helps" as a broadcast. That's not a >> directed broadcast, though, and will work even if router forwarding of >> directed broadcasts is disabled, which is the default these days. Instead, >> it's a broadcast sent by the router (it has the router's IP address as >> source, on behalf of some other station, to a local LAN, because the >router >> is acting as a proxy, for example, a DHCP Relay Agent.) Was that a run-on >> sentence, or what? :-) >> >> A directed broadcast is directed from afar into a subnet. The sender >usually >> makes classful assumptions, since it can't actually know the local >> definition of a broadcast. It's used by ping scan to send a ping to >> 172.16.255.255, for example, in an attempt to ping everyone on network >> 172.16.0.0. Routers don't forward those these days because of the security >> risks. >> >> Back to NetBIOS. It does send a lot of broadcast traffic for naming >> purposes. In an IP environment, however, a host can be configured to send >> unicast naming queries and name registrations to a WINS server. There are >> probably lots of other issues, though. It really can be quite a pain to >get >> it to work correctly when you migrate from a small LAN to a larger >> internetwork with WANs, subnetting, VLANs, etc. >> >> >> I wonder what the original poster is really trying to do and where he can >> get a good Windows networking (internetworking) design guide. Cisco used >to >> have one, but it's probably way dated now.... >> >> >> Well, it's late and my writing is deteriorating. Howard covers directed >> broadcasts, by the way, (and a much better description of the OSI model, >> without reference to the dwarves, as I recall, although possibly with >> reference to the deadly sins) in his CertificationZone papers. I recommend > > them. >> >> Priscilla >> >> >> > >> > once i tried to answer a question with regards to bgp and a >> > 1720 router and only after howard helped us out was it clear >> > that the processor does play an important role. ;-) >> > >> > this time only after the input from priscilla is everybody >> > happy about the netbios/netbeui issue. ;-) >> > >> > but then i think what is important is that we dig a bit deeper >> > into some topics! >> > >> > Good work! Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=71239&t=71084 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
