communicating over the network cisco pdf

... in the message display window in Figure 3.4 The two parts of the message can clearly be seen At the top is the header with the sender’s name, date, phone, subject and list of other people the ... describes the subject of the group The name consists of alphabetic character strings separated by periods The first part of the newsgroup name identifies the type of group followed by the subject of the ... within the requirements of their particular electronic mail system The mail server is the name of the computer through which your electronic mail passes and is separated from the user name by the...

Ngày tải lên: 09/06/2016, 14:46

... perspective of the service provider (on the global “network edge”) Taken together, these viewpoints will allow us to see exactly how the network works, inside and out Let’s explore the Illustrated Network ... addressing only the last two octets are shown. FIGURE 1.1 The Illustrated Network, showing the routers, links, and hosts on the network Many of the layer addresses used in this book appear in the fi gure ... LAN as well The home offi ce link uses digital Major Parts of the Illustrated Network The Illustrated Network is composed of four major components At the top are two Ethernet LANs with the hosts...

Ngày tải lên: 04/07/2014, 07:20

... signaling protocol to estab- lish connections on the fl y, node by node through the network from the source (the “caller”) host to the destination (the “callee”) host. Permanent connections are ... how TCP looks on the Illustrated Network. THE TCP HEADER The TCP header is the same for IPv4 and IPv6 and is shown in Figure 11.2. We’ve already talked about the port fi elds in the previous chapter ... intended to raise the priority of the segment. ACK If set, the Acknowledgment Number fi eld is valid. PSH If set, the receiver should not buffer the segment data, but pass them directly to the application....

Ngày tải lên: 04/07/2014, 07:20

... interface in a TCP/IP network The socket interface forms the boundary between the application program written by the programmer and the network processes that are usually bundled with the operating ... isolating the network program developers from any of the details of how the TCP/IP network actually operates In many cases, the application programmers interpret this “transparency” of the TCP/IP network ... who have been in the computer and network business almost from the start, the socket interface controversy in this regard closely mirrors the controversy that erupted when COBOL, the fi rst “high-level”...

Ngày tải lên: 04/07/2014, 07:20

... the cost to reach network 192.168.44.0 from this router could be the same (3) over E1 as it is over E2. The E1 interface is most likely in the table because the update from the neighbor router ... protocol, the network should be able to converge around the new topology. The routers at each end of the link, since they are locally connected to the interface (direct), will notice the outage ... adjacent routers until the packet TTL expires, even though the destination is reachable over another link. The “bouncing effect” will last until the network converges on the new topology. However,...

Ngày tải lên: 04/07/2014, 08:20

... runs on links between the border routers of these routing domains and shares information about the routes within the AS or learned by the AS with the AS on the other side of the “border.” BGP makes ... numbers The AS range 64512 through 65535 is reserved for private AS numbers Inside the AS, the network was assumed to be under the control of a single network administrator Within the AS, local network ... get there from here,” all will be fi ne at the little network in the middle BGP summarizes all that is known about the IP address space inside the local AS and advertises this information to other...

Ngày tải lên: 04/07/2014, 08:20

... of the terms commonly used in an IP multicast network The key component of the multicast network is the multicast-capable router, which replicates the packets The routers in the IP multicast network, ... router—the (S,G) notation—to the network—the (*,G) notation knows only the RP Exactly how the RP fi nds the unicast IP address of the source varies, but there must be some method to determine the ... know the addresses of the sources for every multicast group All they need to know is the IP address of the RP router The RP router knows the sources for all multicast groups The RP model shifts the...

Ngày tải lên: 04/07/2014, 08:20

... label-switched path The LSP is a unidirectional connection following the same path through the network Ingress router —The ingress router is the start of the LSP and where the label is pushed onto the packet ... the ISP As shown in the fi gure, a packet bound for 10.10.100.0/24 entering the border router from the upstream ISP is known, thanks to the IBGP information, to have to exit the ISP at the other ... of them), but the principle is the same Only the local packets with destinations within the ISP technically need to be routed by the interior routers Transit packets can be sent directly to the...

Ngày tải lên: 04/07/2014, 08:20

... administered in TCP/IP: the network portion of the IPv4 or IPv6 address and the domain name that goes along with it The host portion of the IP address and the further qualifi cation of the domain name ... for the zone ISPs typically run their own DNS servers, often for their customers, with the actual number of systems for each ISP depending on the size of the ISP At the top of the pyramid is the ... “maintain” the database records (surely the lowest maintenance task on the Internet) and the need to update the ISP’s database when changes to FQDN or IP addressing take place on the local network...

Ngày tải lên: 04/07/2014, 08:20

... access their email through their Web browser, which is a tribute to the versatility of the protocols used to make the Web such a vital part of the Internet experience There is no need to repeat the ... URLs over the years URLs are a subset of URIs, and like URIs, consist of two parts: a method used to access the resource, and the location of the resource itself Together, the parts of the ... component means that the date and time on the page are kept current. FIGURE 22.3 Capture of the HTTP for the ASP page, showing how the protocol identifi es the “make and model” of the Web site (Microsoft...

Ngày tải lên: 04/07/2014, 08:20

... responsible for the network device ■ sysName(5)—The name of the manufacturer of the network device ■ sysLocation(6)—The physical location of the network device ■ sysServices(7)—The services the network ... large networks There is a potential problem with man-aging SNMP devices on a network over the network itself (security is another matter) The problem is simply this: What if the link to the network ... congestion on the network The problem is that all of these SNMP messages fl owing over the network back and forth to all of the network devices can add a considerable load to a network at the worst...

Ngày tải lên: 04/07/2014, 08:20

... password, the data provided are the password itself There can be other messages exchanged, depending on the authentication request But ultimately the server issues an authentication response The response ... authentication request, which prompts the server to reply with a list of the authentication methods the client can choose to continue the process In other words, if the server requires any authentication ... do is exchange their A* and B* numbers over the network—not caring who sees them (which they can’t help anyway) But wait, couldn’t someone easily fi gure out the A and B values in the example?...

Ngày tải lên: 04/07/2014, 08:20

... Devices and their Role on the Network • The network devices that people are most familiar with are called end devices These devices form the interface between the human network and the underlying ... www.bkacad.com The Internet – A Network of Networks • • • A global mesh of interconnected networks (internetworks) meets these human communication needs The Internet is created by the interconnection of networks ... Area Networks • • Networks infrastructures can vary greatly in terms of: – The size of the area covered – The number of users connected – The number and types of services available Local Area Network...

Ngày tải lên: 12/12/2013, 14:15

... Reproduced with permission of the copyright owner Further reproduction prohibited without permission Reproduced with permission of the copyright owner Further reproduction prohibited without ... permission Reproduced with permission of the copyright owner Further reproduction prohibited without permission Reproduced with permission of the copyright owner Further reproduction prohibited without ... permission Reproduced with permission of the copyright owner Further reproduction prohibited without permission Reproduced with permission of the copyright owner Further reproduction prohibited without...

Ngày tải lên: 22/12/2013, 21:16

... computer networking protocol suite The terms are often used interchangeably Strictly speaking, the suite is the definition of the protocols, and the stack is the software implementation of them 24 Network ... a network is carried on a medium The medium provides the channel over which the message travels from source to destination Network media: The medium over which the message travels Metallic wires ... Providers) Often also TSPs Connect their customers to the Internet The Internet – ISPs connected to other ISPs 20 The Internet – A Network of Networks •Although there are benefits to using a LAN...

Ngày tải lên: 01/04/2014, 12:20

... location and network them together using H.323 (running on a Cisco IOS gatekeeper) You can then use the zone bandwidth feature to limit the number of calls and force overflow to the Public Switched ... at a Voice over Data design for a customer who wants to replace voice trunk lines in a private voice network Which of the following considerations are important as part of the Voice Network Assessment? ... are out of service if the WAN goes down unless there is dial backup d All the above e A and B only 5) Consider this scenario You want to connect your IP Telephony network to the central office switch...

Ngày tải lên: 18/01/2014, 05:20

... part of the VRF, the hosts in the authentication VLAN are removed from the original global network and isolated from the rest of the network because the VRF is a separate routing table The result ... tunnel overlays A tunnel overlay (either in a full or partial mesh) is created for the authentication network In this design, the access VLANs are placed into the global table The tunnel overlay ... a user connects to the network, they are placed into an authentication VLAN by the NAC Appliance Manager The authentication VLAN has very limited access to the rest of the network; typically,...

Ngày tải lên: 24/01/2014, 10:20

... CCNA, CCNP, Cisco, the Cisco Certified Internetwork Expert logo, Cisco IOS, the Cisco IOS logo, Cisco Press, Cisco Systems, Cisco Systems Capital, the Cisco Systems logo, Empowering the Internet ... from Cisco CallManager to the phone where a call state is active during a failover The Cisco Agent Desktop will re-register to the CTIM configured in the JTAPI preferences on the local PC The ... valid Cisco service contracts, the Cisco Technical Assistance Center (TAC) provides 24-hour, award-winning technical support services, online and over the phone Cisco. com features the Cisco TAC...

Ngày tải lên: 24/01/2014, 10:20

... in the IP Suite of Protocols Layer Attacks Layer and Layer Attacks The Cisco Secure Network Intrusion Detection System What Is the Cisco Secure Network Intrusion Detection System? The Probe The ... How the OSI Model Works Transport Layer Protocols The Internet Layer The Network Layer Composition of a Data Packet Ethernet Security in TCP/IP Cisco IP Security Hardware and Software The Cisco ... Private Networks and Remote Access Introduction Overview of the Different VPN Technologies The Peer Model The Overlay Model Link Layer VPNs Network Layer VPNs Tunneling VPNs Virtual Private Dial Networks...

Ngày tải lên: 24/01/2014, 10:20

... CES d STUN 28) In ATM the AAL Cell Tax refers to the fact that the number of bytes in the AAL varies from to bytes and that these bytes are subtracted from the size of the remaining 48 bytes ... ne twork and the PSTN c Is optional in H.323 networks d All of the above e None of the above 46) In implementing Voice over Data networks, in all likelihood you will be able to use the legacy dial ... under the uOne architecture involves which of the following protocols: a SMTP b Lightweight Directory Access Protocol (LDAP) c Cisco Skinny d All the above e None of the above 16) Which of these...

Ngày tải lên: 24/01/2014, 19:20