Chia sẻ: Thanh Cong | Ngày: | Loại File: PDF | Số trang:50

0
53
lượt xem
18

Mô tả tài liệu

Tham khảo tài liệu 'tcp/ip network administration- p14', công nghệ thông tin, quản trị mạng phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả

Chủ đề:

Bình luận(0)

Lưu

## Nội dung Text: TCP/IP Network Administration- P14

1. [Appendix B] B.10 Control Statements proto proto | all aspath aspath_regexp origin any | igp | egp | incomplete [restrict] | [[metric metric] { route_filter [restrict | metric metric] ; }] ; The source of the routes can be any one protocol (proto) or all (all) protocols. The importation of routes can be controlled by matching their AS paths against the AS path regular expression (aspath_regexp) or by matching their addresses against the route_filter. Route filters and AS path regular expressions are explained above. To export routes learned from RIP and HELLO, use this export list syntax: proto rip | hello [interface interface_list | gateway gateway_list] [restrict] | [[metric metric] { route_filter [restrict | metric metric] ; }] ; The export of RIP and HELLO routes may be controlled by protocol, source interface, source gateway, or route filter. To export routes learned from OSPF, use this export list syntax: proto ospf | ospfase [restrict] | [[metric metric] { route_filter [restrict | metric metric] ; }] ; The export of OSPF and OSPF ASE routes may be controlled by protocol and route filter. Exporting OSPF routes can also be controlled by tag using the syntax shown below: proto proto | all tag tag [restrict] | [[metric metric] { route_filter [restrict | metric metric] ; }] ; OSPF and RIP version 2 provide a tag field. For all other protocols, the tag is always 0. Routes may be selected based on the contents of the tag field. There are other sources of routes that are not true routing protocols, and export lists can be defined for Please purchase PDF Split-Merge on www.verypdf.com to remove this watermark. file:///C|/mynapster/Downloads/warez/tcpip/appb_10.htm (7 of 8) [2001-10-15 09:19:19]
2. [Appendix B] B.10 Control Statements these sources. The two export lists for these sources are: proto direct | static | kernel [interface interface_list] [restrict] | [[metric metric] { route_filter [restrict | metric metric] ; }] ; The export of these routes can be controlled based on the source "protocol" and the source interface. The "protocols" in this case are routes to direct interfaces, static routes, or routes learned from the kernel. proto default | aggregate [restrict] | [[metric metric] { route_filter [restrict | metric metric] ; }] ; The export of these routes may only be controlled based on source "protocol." default refers to routes created by the gendefault option. aggregate refers to routes created by the aggregate statements, the topic of the next section. Previous: B.9 static TCP/IP Network Next: B.11 The Aggregate Statements Administration Statements B.9 static Statements Book Index B.11 The Aggregate Statements [ Library Home | DNS & BIND | TCP/IP | sendmail | sendmail Reference | Firewalls | Practical Security ] Please purchase PDF Split-Merge on www.verypdf.com to remove this watermark. file:///C|/mynapster/Downloads/warez/tcpip/appb_10.htm (8 of 8) [2001-10-15 09:19:19]
4. [Appendix B] B.11 The Aggregate Statements Only aggregate routes learned from the specified protocol. The value of proto may be any currently configured protocol. This includes the "protocols" direct, static, and kernel, discussed in the previous section; all for all possible protocols; and aggregate for other route aggregations. as as_number Only aggregate routes learned from the specified autonomous system. tag tag Only aggregate routes with the specified tag. aspath aspath_regexp Only aggregate routes that match the specified AS path. restrict Indicates routes that are not to be aggregated. Routes that match the route filters may contribute to the aggregate route. A route may only contribute to an aggregate route that is more general than itself. Any given route may only contribute to one aggregate route, but an aggregate route may contribute to a more general aggregate. A slight variation of aggregation is the generation of a route based on the existence of certain conditions. The most common usage for this is to create a default based on the presence of a route from a peer on a neighboring backbone. This is done with the generate statement. generate default | address [mask mask | masklen number] [preference preference] { proto proto [as as_number | tag tag | aspath aspath_regexp] [restrict] | [[preference preference] { route_filter [restrict | preference preference]] ; }; }; The generate statement uses many of the same options as the aggregate statement. These options are described earlier in this appendix. Previous: B.10 Control TCP/IP Network Next: C. A named Statements Administration Reference B.10 Control Statements Book Index C. A named Reference Please purchase PDF Split-Merge on www.verypdf.com to remove this watermark. file:///C|/mynapster/Downloads/warez/tcpip/appb_11.htm (2 of 3) [2001-10-15 09:19:19]
5. [Appendix B] B.11 The Aggregate Statements [ Library Home | DNS & BIND | TCP/IP | sendmail | sendmail Reference | Firewalls | Practical Security ] Please purchase PDF Split-Merge on www.verypdf.com to remove this watermark. file:///C|/mynapster/Downloads/warez/tcpip/appb_11.htm (3 of 3) [2001-10-15 09:19:19]
6. [Appendix C] A named Reference Previous: B.11 The Appendix C Next: C.2 named.boot Aggregate Statements Configuration Commands C. A named Reference Contents: The named Command named.boot Configuration Commands Zone File Records This appendix provides detailed information about named syntax and the commands and files used to configure it. This is primarily a reference to use in conjunction with the tutorial information in Chapter 8, Configuring DNS Name Service . This information is useful to any domain administrator. C.1 The named Command The server side of DNS is run by the name server daemon, named. The syntax of the named command is: [1] [1] Sun systems use in.named instead of named. named [-d level] [-p port[/localport]] [[-b] bootfile] [[-q] [[-r] The three options used on the named command line are: -d level Logs debugging information in the file /usr/tmp/named.run. The argument level is a number from 1 to 9. A higher level number increases the detail of the information logged, but even when level is set to 1, the named.run file grows very rapidly. Whenever you use debugging, keep an eye on the size of the named.run file and use SIGUSR2 to close and remove the file if it gets too large. Signal handling is covered in the next section. It is not necessary to turn on debugging with the -d option to receive error messages from named. named displays error messages on the console and stores them in the messages, even if debugging is not specified. The -d option provides additional debugging information. Please purchase PDF Split-Merge on www.verypdf.com to remove this watermark. file:///C|/mynapster/Downloads/warez/tcpip/appc_01.htm (1 of 3) [2001-10-15 09:19:20]
8. [Appendix C] A named Reference Debugging information is written to /usr/tmp/named.run just as it is when the -d option is used on the named command line. Debugging does not have to be enabled with the -d option for the SIGUSR1 signal to work. SIGUSR1 allows debugging to be turned on when a problem is suspected, without stopping named and restarting it with the -d option. SIGUSR2 Turns off debugging and closes /usr/tmp/named.run. After issuing SIGUSR2, you can examine named.run or remove it if it is getting too large. Optionally, some other signals can be handled by named. These additional signals require named to be compiled with the appropriate options to support the signals: SIGABRT Writes statistics data to /var/tmp/named.stats. named must be compiled with -DSTATS for this signal to work. SIGSYS Writes profiling data into the /var/tmp directory. named must be compiled with profiling to support this signal. SIGTERM Writes back the primary and secondary database files. This is used to save data modified by dynamic updates before the system is shut down. named must be compiled with dynamic updating enabled. SIGWINCH Toggles logging of all incoming queries via syslogd. named must be compiled with QRYLOG option to support this. Previous: B.11 The TCP/IP Network Next: C.2 named.boot Aggregate Statements Administration Configuration Commands B.11 The Aggregate Book Index C.2 named.boot Configuration Statements Commands [ Library Home | DNS & BIND | TCP/IP | sendmail | sendmail Reference | Firewalls | Practical Security ] Please purchase PDF Split-Merge on www.verypdf.com to remove this watermark. file:///C|/mynapster/Downloads/warez/tcpip/appc_01.htm (3 of 3) [2001-10-15 09:19:20]
13. [Appendix C] C.3 Zone File Records Previous: C.2 named.boot Appendix C Next: D. A dhcpd Reference A named Reference Configuration Commands C.3 Zone File Records Two types of entries are used to construct a zone file: control entries that simplify constructing the file, and standard resource records that define the domain data contained in the zone file. While there are several types of standard resource records, there are only two control statements. These are: $INCLUDE filename Identifies a file that contains data to be included in the zone file. The data in the included file must be valid control entries or standard resource records.$INCLUDE allows a large zone file to be divided into smaller, more manageable units. The filename specified on the command line is relative to the directory named on the directory statement in the named.boot file. For example: if the named.boot file for almond contains a directory /etc statement, and a zone file on almond contains an $INCLUDE sales.hosts statement, then the file /etc/sales.hosts would be included in that zone file. If you don't want the filename to be relative to that directory, specify a fully qualified name, such as /usr/dns/sales.hosts.$ORIGIN domainname Changes the default domain name used by subsequent records in the zone file. Use this command to put more than one domain in a zone file. For example, an $ORIGIN sales statement in the nuts.com zone file sets the domain name to sales.nuts.com. All subsequent resource records would be relative to this new domain. The named software uses$ORIGIN statements to organize its own information. Dumping the named database, with the SIGINT signal, produces a single file containing all the information that the server knows. This file, named_dump.db, contains many $ORIGIN entries used to place all of the domains that named knows about into a single file. These two control entries are helpful for organizing and controlling the data in a zone file, but all of the actual database information comes from standard resource records. All of the files pointed to by named.boot contribute to the DNS database, so all of these files are constructed from standard resource records. Please purchase PDF Split-Merge on www.verypdf.com to remove this watermark. file:///C|/mynapster/Downloads/warez/tcpip/appc_03.htm (1 of 16) [2001-10-15 09:19:23] 14. [Appendix C] C.3 Zone File Records C.3.1 Standard Resource Records The format of standard resource records, sometimes called RRs, is defined in RFC 1033, the Domain Administrators Operations Guide. The format is: [name] [ttl] class type data The individual fields in the standard resource record are: name This is the name of the object affected by this resource record. The named object can be as specific as an individual host, or as general as an entire domain. The string entered for name is relative to the current domain unless a fully qualified domain name is used. [4] Certain name values have special meaning. These are: A blank name field denotes the current named object. The current name stays in force until a new name value is encountered in the name field. This permits multiple RRs to be applied to a single object without having to repeat the object's name for each record. .. Two dots in the name field refer to the root domain. However, a single dot (the actual name of the root) also refers to the root domain, and is more commonly used. @ A single at-sign (@) in the name field refers to the current origin. The origin is a domain name derived by the system from the current domain name or explicitly set by the system administrator using the$ORIGIN command. * An asterisk in the name field is a wildcard character. It stands for a name composed of any string. It can be combined with a domain name or used alone. Used alone, an asterisk in the named field means that the resource record applies to objects with names composed of any string of characters plus the name of the current domain. Used with a domain name, the asterisk is relative to that domain. For example, *.bitnet. in the name field means any string plus the string .bitnet. [4] The FQDN must be specified all the way to the root; i.e., it must end with a dot. ttl Please purchase PDF Split-Merge on www.verypdf.com to remove this watermark. file:///C|/mynapster/Downloads/warez/tcpip/appc_03.htm (2 of 16) [2001-10-15 09:19:23]