At 11:40 AM 11/17/01, Jonathan Hays wrote: >Priscilla Oppenheimer wrote: > > > way, is another set of documents that I trust, (although the ARP tutorial > > has the usual misconceptions in it, which is very disappointing.) > >Priscilla, >I don't remember reading that paper and unfortunately I have let my >membership elapse. >Could you share what these common misconceptions are, and if possible, >point us to a >more accurate source of information written in plain English (that means >non-RFC)? >Thanks.
Here's a copy of the message I sent to CertificationZone over two weeks ago about the ARP errors. I thought they would fix them. An ARP frame does not have an IP header. Figure 2 should show a real ARP frame. Note that the destination is six sets of FFs (not the four in the figure) and that there's no IP layer. Ethernet Header Destination: FF:FF:FF:FF:FF:FF Ethernet Broadcast Source: 00:00:0C:05:3E:80 Protocol Type:0x0806 ARP - Address Resolution Protocol Hardware: 1 Ethernet (10Mb) Protocol: 0x0800 IP Hardware Address Length: 6 Protocol Address Length: 4 Operation: 1 ARP Request Sender Hardware Address: 00:00:0C:05:3E:80 Sender Internet Address: 172.16.10.1 Target Hardware Address: 00:00:00:00:00:00 Target Internet Address: 172.16.10.10 Figure 3 needs to be fixed also. A reply doesn't have an IP header either. Does this matter? Yes. If you set a filter to capture just IP packets with a protocol analyzer or debugged just IP packets on a router, for example, you would miss all the ARPs since they aren't IP packets. Plus we expect accuracy from CertificationZone! ;-) Priscilla ________________________ Priscilla Oppenheimer http://www.priscilla.com Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=26596&t=25925 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
