* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Chapter 12 NM Tools and Systems
Survey
Document related concepts
Asynchronous Transfer Mode wikipedia , lookup
Dynamic Host Configuration Protocol wikipedia , lookup
Distributed firewall wikipedia , lookup
Net neutrality law wikipedia , lookup
Deep packet inspection wikipedia , lookup
Point-to-Point Protocol over Ethernet wikipedia , lookup
Piggybacking (Internet access) wikipedia , lookup
Computer network wikipedia , lookup
Airborne Networking wikipedia , lookup
IEEE 802.1aq wikipedia , lookup
Network tap wikipedia , lookup
Wake-on-LAN wikipedia , lookup
TCP congestion control wikipedia , lookup
Internet protocol suite wikipedia , lookup
Recursive InterNetwork Architecture (RINA) wikipedia , lookup
Transcript
Network Management Tools ifConfig (UNIX) • Used to assign/read an address to/of an interface • Option -a is to display all interfaces • Notice two interface loop-back (lo0) and Ethernet (hme0) [/home/staff/ycchen]ifconfig -a lo0: flags=849<UP,LOOPBACK,RUNNING,MULTICAST> mtu 8232 inet 127.0.0.1 netmask ff000000 hme0: flags=863<UP,BROADCAST,NOTRAILERS,RUNNING,MUL TICAST> mtu 1500 inet 163.22.20.16 netmask ffffff00 broadcast 163.22.20.255 ifconfig le0 down ifconfig le0 163.22.20.16 netmask 255.255.255.0 broadcast 163.22.20.255 ipconfig (Windows) ipconfig (internet protocol configuration) ipconfig /? /? /all /release /release6 /renew /renew6 /flushdns /registerdns /displaydns help 顯示完整設定資訊 釋放 IPv4 位址 釋放IPv6 位址 更新 IPv4 位址 更新Pv6 位址 清除 DNS 解析快取 重新整理 DHCP 租用並重新登錄 DNS 顯示 DNS 解析快取內容 ipconfig 無線區域網路介面卡 無線網路連線: 連線特定 DNS 尾碼 . . . . . . . . : 連結-本機 IPv6 位址 . . . . . . . : fe80::19e4:8b36:e72b:2cf%11 IPv4 位址 . . . . . . . . . . . . : 192.168.0.107 子網路遮罩 . . . . . . . . . . . .: 255.255.255.0 預設閘道 . . . . . . . . . . . . .: 192.168.0.1 ipconfig /all 無線區域網路介面卡 無線網路連線: 連線特定 DNS 尾碼 . . . . . . . . : 描述 . . . . . . . . . . . . . . .: Atheros AR5BWB225 Wireless Network Adapter 實體位址 . . . . . . . . . . . . .: 74-DE-2B-CB-49-0C DHCP 已啟用 . . . . . . . . . . . : 是 自動設定啟用 . . . . . . . . . . .: 是 連結-本機 IPv6 位址 . . . . . . . : fe80::19e4:8b36:e72b:2cf%11(偏好選項) IPv4 位址 . . . . . . . . . . . . : 192.168.0.107(偏好選項) 子網路遮罩 . . . . . . . . . . . .: 255.255.255.0 租用取得 . . . . . . . . . . . . .: 2013年4月5日 下午 07:58:09 租用到期 . . . . . . . . . . . . .: 2013年4月6日 下午 07:59:14 預設閘道 . . . . . . . . . . . . .: 192.168.0.1 DHCP 伺服器 . . . . . . . . . . . : 192.168.0.1 DHCPv6 IAID . . . . . . . . . . . : 292871723 DHCPv6 用戶端 DUID. . . . . . . . : 00-01-00-01-17-23-19-FF-74-DE-2B-CB-49-0C DNS 伺服器 . . . . . . . . . . . .: 192.168.0.1 NetBIOS over Tcpip . . . . . . . .: 啟用 手動設定IP位址 NAT - Network Address Translation © 2011 Pearson Education, Inc. Publishing as Prentice Hall 9 http://www.whatismyip.com/ Address Resolution Protocol RFC 826 To map network addresses to the hardware addresses used by a data link protocol To translate IP addresses to Ethernet MAC addresses Use data-link broadcast ARP Request, ARP Reply ARP Announcement Gratuitous ARP ARP Spoofing (ARP Poisoning) Send fake, or 'spoofed', ARP messages to an Ethernet LAN. Generally, to associate the attacker's MAC address with the IP address of another node (such as the default gateway). Passive sniffing, Man-in-the-middle attack, Denial-of-service attack http://www.oxid.it/downloads/apr-intro.swf ARP Cache Default cache time-outs: arp arp arp arp -a -d 10.10.34.235 -d * –s 157.55.85.212 C:\>arp -a Interface: 10.10.34.169 Internet Address 10.10.34.231 10.10.34.234 10.10.34.235 10.10.34.254 Two-minute (unused entries) Ten-minute (used entries) 00-aa-00-62-c6-09 --- 0x2 Physical Address 00-12-cf-28-cd-20 00-12-cf-29-c6-80 00-12-cf-28-1e-20 00-08-e3-dd-b3-1f Type dynamic dynamic dynamic dynamic C:\>arp -s 10.10.34.235 00-12-cf-28-1e-20 C:\>arp –a Interface: 10.10.34.169 Internet Address 10.10.34.235 10.10.34.254 --- 0x2 Physical Address 00-12-cf-28-1e-20 00-08-e3-dd-b3-1f Type static dynamic Routing information route print route -4 print route -6 print route add 163.22.16.0 mask 255.255.255.0 192.168.0.254 metric 100 if 11 route add 163.22.16.0 mask 255.255.255.0 192.168.0.254 metric 100 route change 163.22.16.0 mask 255.255.255.0 192.168.0.254 metric 130 route delete 163.22.16.0 netstat -r 領域名稱系統(DNS) 提供主機名稱與IP位址之轉換 www.im.ncnu.edu.tw 163.22.20.16 由DNS伺服器提供 RR-DNS (Round Robin DNS) www.yahoo.com: (8台伺服器) 66.218.71.90, 66.218.71.80, 66.218.71.95, … DDNS (Dynamic DNS) 主機名稱 浮動IP位址 ipconfig /displaydns ipconfig /flushdns nslookup C:\>nslookup Default Server: academic.ncnu.edu.tw Address: 163.22.2.1 > www.cnn.com Server: academic.ncnu.edu.tw Address: 163.22.2.1 Non-authoritative answer: Name: www.cnn.com Addresses: 64.236.29.120, 64.236.91.21, 64.236.16.20, 64.236.16.52 64.236.16.84, 64.236.24.12, 64.236.24.20, 64.236.24.28 > 163.22.20.16 Server: academic.ncnu.edu.tw Address: 163.22.2.1 Name: euler.im.ncnu.edu.tw Address: 163.22.20.16 Aliases: 16.20.22.163.in-addr.arpa > nslookup • An interactive program for querying Internet Domain Name System servers • Converts a hostname into an IP address and vice versa querying DNS • Useful to identify the subnet a host or node belongs to • Lists contents of a domain, displaying DNS record DNS Lookup Ping Most basic tool for internet management Based on ICMP ECHO_REQUEST message Available on all TCP/IP stacks Useful for measuring • Connectivity • Packet Loss • Round Trip Time Can do auto-discovery of TCP/IP equipped stations on single segment ping Usage: ping [-t] [-a] [-n count] [-l size] [-f] [-i TTL] [-v TOS] [-r count] [-s count] [[-j host-list] | [-k host-list]] [-w timeout] destination-list Options: -t -a -n -l -f -i -v -r -s -j -k -w count size TTL TOS count count host-list host-list timeout Ping the specified host until stopped. To see statistics and continue - type Control-Break; To stop - type Control-C. Resolve addresses to hostnames. Number of echo requests to send. Send buffer size. Set Don't Fragment flag in packet. Time To Live. Type Of Service. Record route for count hops. Timestamp for count hops. Loose source route along host-list. Strict source route along host-list. Timeout in milliseconds to wait for each reply. Example C:\>ping -n 10 -l 256 www.im.ncnu.edu.tw Pinging euler.im.ncnu.edu.tw [163.22.20.16] with 256 bytes of data: Reply Reply Reply Reply Reply Reply Reply Reply Reply Reply from from from from from from from from from from 163.22.20.16: 163.22.20.16: 163.22.20.16: 163.22.20.16: 163.22.20.16: 163.22.20.16: 163.22.20.16: 163.22.20.16: 163.22.20.16: 163.22.20.16: bytes=256 bytes=256 bytes=256 bytes=256 bytes=256 bytes=256 bytes=256 bytes=256 bytes=256 bytes=256 time=1ms time=1ms time=1ms time=1ms time=1ms time=1ms time=1ms time=1ms time=1ms time=1ms TTL=253 TTL=253 TTL=253 TTL=253 TTL=253 TTL=253 TTL=253 TTL=253 TTL=253 TTL=253 Ping statistics for 163.22.20.16: Packets: Sent = 10, Received = 10, Lost = 0 (0% loss), Approximate round trip times in milli-seconds: Minimum = 1ms, Maximum = 1ms, Average = 1ms traceroute/tracert tracert www.hinet.net Usage: tracert [-d] [-h maximum_hops] [-j host-list] [-w timeout] target_name Options: -d Do not resolve addresses to hostnames. -h maximum_hops Maximum number of hops to search for target. -j host-list Loose source route along host-list. -w timeout Wait timeout milliseconds for each reply. C:\>tracert www.facebook.com 在上限 30 個躍點上 追蹤 star.c10r.facebook.com [31.13.82.1] 的路由: 1 2 3 4 5 6 7 8 9 10 11 12 8 ms 8 ms 9 ms 11 ms 16 ms 11 ms 12 ms 96 ms 97 ms 97 ms 97 ms 99 ms 8 ms 8 ms h254.s98.ts.hinet.net [168.95.98.254] 8 ms 8 ms 168.95.220.98 8 ms 8 ms NTNK-3101.hinet.net [220.128.21.110] 11 ms 11 ms tchn-3011.hinet.net [220.128.16.98] 14 ms 14 ms TPDT-3011.hinet.net [220.128.16.6] 12 ms 11 ms r4103-s2.tp.hinet.net [220.128.7.29] 13 ms 12 ms r4003-s2.tp.hinet.net [220.128.7.229] 96 ms 96 ms 211-72-233-77.HINET-IP.hinet.net [211.72.233.77] 97 ms 97 ms ae-5.r00.tokyjp03.jp.bb.gin.ntt.net [129.250.5.29] 98 ms 97 ms ae-0.facebook.tokyjp03.jp.bb.gin.ntt.net [61.213.145.74] 97 ms 97 ms po126.msw01.01.nrt1.tfbnw.net [31.13.27.221] 99 ms 99 ms edge-star-ecmp-01-nrt1.facebook.com [31.13.82.1] http://www.visualroute.com/ netstat C:\>netstat -n -a Active Connections Proto Local Address Foreign Address State TCP 0.0.0.0:21 0.0.0.0:0 LISTENING TCP 0.0.0.0:135 0.0.0.0:0 LISTENING TCP 0.0.0.0:445 0.0.0.0:0 LISTENING TCP 0.0.0.0:1234 0.0.0.0:0 LISTENING TCP 0.0.0.0:1235 0.0.0.0:0 LISTENING TCP 0.0.0.0:1236 0.0.0.0:0 LISTENING TCP 163.31.153.68:1234 163.22.3.4:80 ESTABLISHED TCP 163.31.153.68:1235 163.22.4.67:80 ESTABLISHED TCP 163.31.153.68:1236 163.22.4.67:80 SYN_SENT UDP 0.0.0.0:135 *:* UDP 0.0.0.0:445 *:* UDP 0.0.0.0:38037 *:* UDP 127.0.0.1:1230 *:* UDP 163.31.153.68:500 *:* NETSTAT [-a] [-e] [-n] [-s] [-p proto] [-r] [interval] -a -e Displays all connections and listening ports. Displays Ethernet statistics. This may be combined with the -s option. -n Displays addresses and port numbers in numerical form. -p proto Shows connections for the protocol specified by proto; proto may be TCP or UDP. If used with the -s option to display per-protocol statistics, proto may be TCP, UDP, or IP. -r Displays the routing table. -s Displays per-protocol statistics. By default, statistics are shown for TCP, UDP and IP; the -p option may be used to specify a subset of the default. interval Redisplays selected statistics, pausing interval seconds between each display. Press CTRL+C to stop redisplaying statistics. If omitted, netstat will print the current configuration information once. TCP Connection Monitoring netstat –p TCP netstat –b –p TCP netstat -e Network Management Tools • SNMP command tools • MIB Walk • MIB Browser SNMP Command Tools • snmptest • snmpget • snmpgetnext • snmpset • snmptrap • snmpwalk • snmpnetstat Network Status • Command: snmpnetstat host community • Useful for finding status of network connections % snmpnetstat noc5 public Active Internet Connections Proto Recv-Q Send-Q Local Address Foreign Address (state) tcp 0 0 *.* *.* CLOSED tcp 0 0 localhost.46626 localhost.3456 ESTABLISHED tcp 0 0 localhost.46626 localhost.3712 ESTABLISHED tcp 0 0 localhost.46626 localhost.3968 ESTABLISHED tcp 0 0 localhost.46626 localhost.4224 ESTABLISHED tcp 0 0 localhost.3456 localhost.46626 ESTABLISHED tcp 0 0 localhost.3712 localhost.46626 ESTABLISHED tcp 0 0 localhost.3968 localhost.46626 ESTABLISHED tcp 0 0 localhost.4224 localhost.46626 ESTABLISHED tcp 0 0 noc5.41472 noc5.4480 ESTABLISHED tcp 0 0 noc5.41472 noc5.4736 ESTABLISHED tcp 0 0 noc5.4480 noc5.41472 ESTABLISHED tcp 0 0 noc5.4736 noc5.41472 ESTABLISHED SNMP Browser • Command: snmpwalk host community [variable name] • Uses Get Next Command • Presents MIB Tree Protocol Analyzer Data Capture Device PROTOCOL ANALYZER Raw data transferred on Modem / WAN or LAN Link LAN • Analyzes data packets on any transmission line including LAN • Measurements Figure made locally orAnalyzer remotely 12.13 Protocol Basic Configuration • Probe (data capture device) captures data and transfers to the protocol analyzer (no storage) • Data link between probe and protocol analyzer either dial-up or dedicated link or LAN • Protocol analyzer analyzes data at all protocol levels RMON Probe PROTOCOL ANALYZER SNMP Traffic Router BACKBONE NETWORK Router SNMP Traffic RMON Probe LAN Communication between probe and analyzer is using SNMP Figure 12.14 Protocolfor Analyzer with RMON Probe • Data gathered and stored an extended period of time and analyzed later • Used for gathering traffic statistics and used for configuration management for performance tuning Network Monitoring with RMON Probe Ethernet Probe Protocol Analyzer Ethernet LAN Router Backbone Network FDDI LAN Router Router FDDI Probe Token Ring LAN Token Ring Probe Backbone Probe Network Statistics • • • • Protocol Analyzers RMON Probe / Protocol analyzer MRTG (Multi router traffic grouper) Home-grown program using tcpdump Traffic Load: Source HostTopN Host 1 Host 2 Host 3 Host 4 Host 5 Host 6 Host 7 Host 8 Host 9 Host 10 0 100 200 Giga Octets 300 400 Traffic Load: Source/Destination Protocol Distribution Network Monitoring • • • • By polling By traps (notifications) Failure indicated by pinging or traps Ping frequency optimized for network load vs. quickness of detection • trap messages: linkdown, linkUp, coldStart, warmStart, etc. • Network topology discovered by auto-discovery Global View Domain View Segment View Node Discovery In a Network Node Discovery Given an IP Address with its subnet mask, find the nodes in the same network. Two Major Approaches: Use ICMP ECHO to query all the possible IP addresses. Use SNMP to query the ARP Cache of a node known Use ICMP ECHO Eg: IP address: 163.25.147.12 Subnet mask: 255.255.255.0 All possible addresses: 163.25.147.1 ~ 163.25.147.254 For each of the above addresses, use ICMP ECHO to inquire the address If a node replies (ICMP ECHO Reply), then it is found. Use SNMP Find a node which supports SNMP The given node, default gateway, or router Or try a node arbitrarily Query the ipNetToMediaTable in MIB-II IP group ipNetToMediaPhysAddress ipNetToMediaType ipNetToMediaIfIndex ipNetToMediaNetAddress 1 2 00:80:43:5F:12:9A 00:80:51:F3:11:DE 163.25.147.10 dynamic(3) 163.25.147.11 dynamic(3) Network Discovery Network Discovery Find the networks to be managed with their interconnections Given a network, find the networks which directly connect with it. Recall that networks are connected via routers. Major Approach Use SNMP Discovering Networks 163.25.145.0 163.25.146.0 140.112.8.0 140.112.6.0 163.25.148.0 163.25.147.0 140.112.5.0 192.168.13.0 192.168.12.0 A Network Discovery Algorithm 1. First use a node discovery algorithm to find all the nodes in the network. 2. For each discovered node, use SNMP to query the ipAddrTable of MIB-II IP group ipAdEntIfIndex ipAdEntBcastAddr ipAdEntAddr ipAdEntNetMask 163.25.145.254 1 255.255.255.0 163.25.145.255 … 162.25.146.254 2 255.255.255.0 163.25.146.255 … 162.25.147.254 3 255.255.255.0 163.25.147.255 … 3. Query the corresponding entries in ipRouteTable to verify the above addresses ipRouteTable