The Illustrated Network- P59 pps

... Level 4. The other client retrieves the message from the email server using POP3 (fetchmail). 5. The local host transfers the message to the local mailbox using ESMTP. 6. The use of these protocols ... recorded in the headers (from “bottom to top”) is: 1. The mail application receives the composed message from the local user. 2. The local mailbox receives the messa...

Ngày tải lên: 04/07/2014, 08:20

... chapters on top of the printer bin, and he began reading it. When I came to retrieve the printout, he was fascinated by the sample chapters. He wanted the book then and there. And as we talked, ... book is a bit of a synthesis of the written and the seen. It attempts to give the reader the opportunity to see common tasks in a real, work- ing, hands-on environment of the p...

Ngày tải lên: 04/07/2014, 07:20

... (rather than transferring the whole fi le to the other host) known as the Network File System (NFS). There is also the Simple Network Management Protocol (SNMP) for network operations. For the ... which the IP layer in hosts and routers route connectionlessly to the destina- tion host. On the receiving side, TCP accepts the incoming segments from the IP layer and deliver...

Ngày tải lên: 04/07/2014, 07:20

... receive comes from the other end as well. THE EVOLUTION OF ETHERNET The original Ethernet was developed at the Xerox Palo Alto Research Center (PARC) in the mid-1970s to link the various mainframes ... Metcalf, the Ethernet inventor, left Xerox and recruited two other companies, one to make chipsets for Ethernet and the other to make the hardware components to employ the...

Ngày tải lên: 04/07/2014, 07:20

... to other routers, have them anyway—this is the only way to make the serial links “visible” to the IP layer and network operations). The Control fi eld is set to 0x03 (0000 0011), which is the ... that there is no sequence numbering in these frames. The UI for- mat is used to indicate that the connectionless IP protocol is in use. The Protocol fi eld identifi es the format an...

Ngày tải lên: 04/07/2014, 07:20

... to the right, there are lots of networks, but none of them can have many hosts. If it is set too far to the left, then there are plenty of hosts allowed, but fewer networks overall. In IP, the ... rules ϭ SONET/SDH Dashed rules ϭ Gig Ethernet Note: All links use 10.0.x.y addressing only the last two octets are shown. FIGURE 4.1 The Illustrated Network IP addressing, showing th...

Ngày tải lên: 04/07/2014, 07:20

... value. The data fi eld in the ICMPv6 message is 1440 bytes long. The rest of the 1510 bytes are from the various headers pasted onto these bytes. Frame 2 holds the rest of the 2000 bytes in the ... information needed for the destination to reassemble the fragments (in this case, two of them). The important fi elds are highlighted in bold in the preceding code. The fi...

Ngày tải lên: 04/07/2014, 07:20

... host knew to ask for the MAC address of the destination host because the destination host is on the same LAN as the source. Hosts with the same IP network addresses must be on the same LAN segment. ... hosts on the same LAN are simply “asked” to provide their MAC addresses. The destination MAC address in the frame is the MAC address that corresponds to the destinati...

Ngày tải lên: 04/07/2014, 07:20

... which is the longest match? The router will keep compar- ing the addresses in the table to the destination address bit by bit until the table runs out of entries. The last match is the longest ... is the 22nd bit in the destination address. There is no longer entry. This makes the /22 entry the longest match for the destination address, and the packet is forwarde...

Ngày tải lên: 04/07/2014, 07:20

... that carry the call for the loss of the use of their own facilities (which could otherwise make money for the company directly) for the duration of the call. Now, in the IP world the source ... arrangement, the fi rst ISP, where the packet originates at a client, gets all of the revenue from the customer. However, the fi rst ISP shares some of this money with the...

Ngày tải lên: 04/07/2014, 07:20