CCNABRAINDUMP1(2)
添加时间: 2007-9-6 0:48:24 作者: Cisco考试认证 阅读次数:37 来源: http://www.d9soft.com
config net [ip add of tftp serv]: load config info from TFTP server, Config t: console / telnet (config from my term)
Catalyst 5000 : to config port, type slot/port (e 4/2 for Ethernet, card 4, port 2), Catalyst 7000 / 7500 VIP (versatile int processor cards): type slot/port adapter/port; e 2/0/1, 3 rd Enet vip card3, first port 0, 2 nd Enet Int.
Auto Install : config router autoly and remotely. New router acts as BootP work stn & gets IP from existing router acts as BootP or RARP server, connects to TFTP server, gets network-config, hostname-config/router-config files.
BootP server: provides (by TFTP) stn.IP add, server IP add and the name of the file to be loaded and booted.
Modes: User EXEC : After log in, you are automly in this mode, basic tests, temp term setup, conn to remote devices (router>), logout to exit, Privileged EXEC: Set OS params, config, debug,(router#) Quit/Exit to exec mode, ROM monitor: Occurs when no cisco IOS image found / boot interrupt (rommon>), Set up: occurs on first switch on, RxBoot : reboot from ext (router), Global config Mode: router(config)> commands affects whole system, exit/end to pre mode
Interface Config mode: router(config-if)# comm for config single int.
Editing: Ctrl+A-beging of line, Ctrl+E-end of line, Ctrl+F(R arrow)-move fwd 1 char, Ctrl+B(L arrow)- back 1 char, Ctrl+P(U arow)-scroll/Rpt prev comm, Ctrl+N(D arow)-recent comm recall, Esc+F-move fwd 1 word, Esc+B-back 1 word.
R>terminal editing / terminal no editing : advanced editing features on / off. R> enable / disable : privileged mode on / off
R>sh history-sh comm buffer, R>term history size- set comm buffer size, Tab: Completes comm entry,
Passwords: config t, Enable secret x, enable password x, line vty 0, login, pw x; line aux 0, login, pw x; line con 0, login, pw x; Banner: config t, banner motd #, xxx # ; Hostname: config t, hostname [newhostname]
Shutting down : config t, # int s0, # shutdown (Admntly down) # no shut down (Turn on)
DTE/DCE Cable: router use synch comm, needs clk, clock rate on DCE.+ specify bandwidth (for IGRP), Config t, int s0, clock rate 56000, bandwidth 56. def clk rate-T1, R# show controllers s0- Identifies serial port cable as DTE or DCE cable.
CSU/DSU : Chl svc unit/Data svc unit. Handles clocking on serial ports (WAN links), not used by Cisco router.
Token Ring Speed : # int token ring 2/0, # early token release, # ring-speed 16 (4-16 mb),
Media type : # int e1, # media type 10baseT, Clock set: R# clock set 11: 02: 01 04 August 1999
Config Comm: RouterR# sh startup-config/config: contents of NVRAM, sh running-config: contents of RAM,
R# erase startup-config (write erase)- erases NVRAM, starts initial config dialog, R# Setup: starts initial config dialog,
R# write term-sh run config, write mem- copy run start, config mem- copy start run, config net [ip ad of tftp ser]-lod config frm tftp, write network/R# copy run tftp (backup, ram>tftp serv), copy tftp run (restore), R# reload: lod startup confi to mem,
IOS Comm: R # copy flash tftp (ios backUp), # copy tftp flash (ios restore), Fallback-gives alternative IOS loading booting sources: config t, # boot system flash [ios_filename], boot system TFTP [ios_filename] [ TFTP_ip add], boot system ROM
R# erase- erases flash, # delete- (if multi flash), if ext flash card # delete-only marks the IOS, # squeeze-deletes IOS.
R# sh flash-flash mem stat, all IOSs file name, # sh version-sh current IOS file (if multi flash), hw config, sw ver, Register setting, boot images, sh process: active process, cpu utilzn, sh mem: mem allctn stat, sh stacks- sh reason for crash/reboot,R# sh buffer- sh buffer stat, sh int- sh all int config, sh proto: sh all layer3 proto config, sh ip proto- IP proto in detail
Cisco Discovery Protocol (CDP): allows access config info on other routers with single command, uses SNAP broadcasts at DLLayer. CDP starts by default (ver10.3/later) & discovers neighboring routers running CDP thro data link broad. updates: 60 sec, holdtime: 180 sec, # config t, # cdp timer 60, # cdp holdtime 180 (global), R# sh cdp int: int stat, config info, encaps, cdp timers. R# sh cdp entry */ routerA: * shows info recd from all routers / only router A. R# sh cdp neighbors: shows cdp updates (device ID, local int/port, holdtime, capability, platform5000, neibhor port ID) (capa- R router, T trans bridge, B source route bridge, S switch, H host, I igmp), R# sh cdp neighbors detail: shows cdp enrty+ sh cdp neighbors
R# sh cdp traffic: reveals amount of pkts sent & recd among neighbors; config t, # no cdp run (cdp off-all int-router),
# config int, # no cdp enable (cdp off- single int)
Telnet : Virtual Term conns: part of tcp/ip proto allows to connect to remote hosts and routers. Cisco supports 5 simultaneous (vty 0 4) telnet sessions. R# telnet [ip add], ip add of any active int on the router. R# exit: to close session.
Ctrl+shift+6 X : return to org router w/o closing telnet. # 1, return: takes back to telnet session
R# sh sessions : sh all telnet sessions/conn no, host, add, byte, idle, conn name.
Hostnames: router can resolve ip add to hostnames. Config t, # ip host routerC 23 172.16.40.2 (23 telnet port- optl),
R # sh host / s: sh all> hosts, flags (perm/temp, ok/ex), age (hrs), type (proto), ip add, t# no ip domain-lookup: disables router DNS lookup (enabled by default), to re-enable DNS lookup, t# ip domain-lookup, t# ip name-server 172.16.30.8 (max 6 add)
IP Add config: config t, # int s0, # IP address [ ip-add] [ subnet-mask] - config IP add, Subnet mask for serial int s0.
# sh interfaces-shows all interface types & their associtd IP adds. use CDP command to see IP add of neighbor routers.
Inter Network Testing : R# telnet : shows all layers are working, verify appl layer commn between the hosts.
R# Ping 172.16.10.1- uses IP & ICMP proto to verify commn at Inet layer between hosts (! echo replay recd, . time out,
U dest un reachable, C congested exp pkt, ping interupted, ? pkt type unknown, & pkt TTL exceeded.)
R# trace ip 172.16.40.2 uses TTL values (!H-recd probe not forward due to access list, P proto un reach, N net unreach,
U port unreach,* time out, (trace used in IP, AppleTalk, CLNS, Vines, Old Vines), R# sh int so : shows line & data link
proto status, R# debug all, # undebug all,
IP Routing : Source and Destn. Hardware add keeps changing, but IP add remains same as pkt travels thro?routers.
Dest IP remains same, frame keeps changing at each hope b’cos source, destn h/w add keeps changing.
Static Routing config t, # ip route [rem net ID] [subnetmask] [def Gway,next hop add / interface][distance]- cisco book
# no ip route [remote net ID]- to cancel a route, # sh ip route-sh R table/all routes, # sh ip route static-sh only static routes,
# ip classless global command to use def routing with static routing to forward pkts destd to obscure subnets to best route. Default Routing : default route = router or gateway of last resort, # ip route [0.0.0.0] [0.0.0.0] [gateway IP/next hop add] # ip default-network 192.68.17.0 : Default route as per Cisco book, # no ip routing (disable), # ip routing (re enable)
Dynamic Routing : Autonomous System(AS): consists of routers that share info using same protocol. Backbone + areas. Routing within area/domain-Intra Domain Routing, Ext / Inter domain / inter AS Routers connect areas to backbone.
Codes- # sh ip route- C-dir conntd, S-static, I-IGRP, R-RIP, M-mobile, B-BGP, D-EIGRP, EX-EIGRP ext,
O-OSPF, IA-OSPF inter area, E1- OSPF ext type1, E2-OSPF ext type2, E-EGP, I-ISIS, L1-ISIS lvl 1, L2-ISIS lvl 2.
Admn distance: Source’s trustworthiness 0-255 : Directly connected Interface-0, Static route-1, EIGRP sum route-5, Ext BGP-20, Int EIGRP-90, IGRP-100, OSPF-110, ISIS-115, RIP-120, EGP-140, Int BGP-200, Unknown-255.
Interior Routing protos:used within an AS. RIP, IGRP (Dist vect), OSPF (Link state), EIGRP (Bal Hybrid) all layer3.
Distance Vector-RIP-uses 2nd hand info, metric (hops 16 ), slow conv. @ 30 sec, routing loops, counting to infinity.
To Stop Loops: Counting to infinity/exceeding TTL: max.16 loops, Split Horizon: stops info return, Route Poisoning: uses net unreachable entry (metric for down link = infinity), and triggered updates. Hold Downs : stops regular updates from reinstating down link, waits & watches status, work with route poisoning, and use triggered updates.
Link State- OSPF- uses LSP (hello pkts), topology Dbase, SPF algorithm, metric-65533, routing table. needs more power, memory, b/w, fast conv @ 2-12 hrs(uses DR designated Router), LSP time stamps,
Balanced Hybrid-IS-IS, EIGRP: combines and uses best of both above. Link state triggers. Classfull routing: summarizing routing info by major network nos.(RIP, IGRP), Classless and Prefix routing : allows contiguous blocks of hosts, subnets or nets to be represented by a single route. Cost= Path Cost: based on hope, bw, etc. to determine the best route. Lower the cost value better the path. Routing metric: method by which routing algorithm decides one route is better than other. Stored in routing table. Includes bw, comm cost, delay, hop count, load, MTU, path cost, and reliability.
RIP: dynamic, dist vect, classful routing proto, no support prefix routing. Provides IP dest add, metric-hop count (16), IP add of next router in the way, marker & flags (recent route change), timer, Hold downs, Split horizon, Poison rev, slow conv, loops. Timers: update-30sec, invalid-180sec, flush-240sec., hold-180sec, Admn Dist.: 120,
RIP pkt format: command1,ver no1, zero2, add family ID2, zero2, add4, zero4, zero4, metric4.
Enab RIP: cancel all stat/def routes, config t, Enab RIP(# router rip),Enab net (# net work x.x.0.0), R# wr mem
Testing RIP: # sh ip route rip, # ping [add]. Passive RIP: stops router from advt to internet. Commands: config t,
# router rip, # network 172.16.0.0, # passive serial 1 ( serial 1 connects the local net to the internet),
Neighbor RIP: WAN link (frame relay) doesn’t broadcast RIP update by default. use neighbor command to solve this.
config t, # router rip, # network 172.16.0.0, # neighbor 172.18.3.10. RIP Broadcast : sending update to 255.255.255.255 via e0
Monitoring RIP: R # sh ip route rip-sh only RIP routes, # sh ip protocol-sh RIP timers, net ID, routing info sources,
# sh ip interface: shows interface config and statistics, R# debug ip rip: turns on RIP debugging-shows RIP updates live,
# undebug ip rip: stops debug, R # trace 172.16.50.2: sh path to dest add, config t # no router rip: stops running RIP proto.
IGRP: Dist vect, cisco prop, scalability, fast convergence, multi paths (def 4, max 6) & unequal load balancing, Periodic & Flash updates, no VLSM, complex metric (1-255) [delay-media speed (10mb=100=1ms), bw (1.2kb-10Gb), reliability (1-255optm), load (optm 0-255), MTU], hold down, poison rev, split horizon,
Timers: update-90s, invalid-270s, holddown-270+10s, Flush-630s, Admn Dist:100
IGRP routes : Interior: routes between subnets, System: routes within AS, Exterior: routes out side AS (1-65655).
Enable IGRP: Enable IGRP with AS no. (config t, # router igrp 10, # network 172.16.0.0, # wr mem )
Monitoring IGRP: R# sh ip route igrp : sh like RIP+ delay, bw, reliabilty, load, R# sh ip route igrp-shows IGRP routes,
R # sh ip protocol-sh all timers, broad freq, etc, R# sh ip int-shows int config, status & global parameters,
R# un / debug ip igrp events / transactions : sh IGRP traffic live, config t # no route igrp-stops IGRP.
OSPF: Link state proto, used within AS, a grp of routers that share a routing proto. Each router retains own dbase.
Huge metric limit 65533, assign cost to a link, load balancing among equal cost links, update-only for a change, pkts carry info for multi routers (tell a friend), can communicate out side AS, supports VLSM, TOS (types of svce routing)
EIGRP: Cisco prop, Balanced Hybrid Proto (best path by dist vect, update by link state), fast conv, support VLSM, partial updates, multi proto support (IP/IPX/Apple talk), update-only for change only for neighbors.
Exterior Routing proto : used outside an AS. More complex, stores more info about more routers.
EGP (Exterior g/way proto): dist vector proto, Dynamic, doesn’t use metrics like interior routing proto, can’t detect or correct routing loops, communicates thro?a core backbone routing net that connects AS together, establishes a set of neighbors to share routing info, send polls to neighbors to check ‘alive? updates other routers within an As.
Message types: neighbor acquisition message to check ‘alive? not, neighbor reachability message to check down/not, Poll messages to collect info about remote hosts?network, Error message to identify various errors.
BGP (Border g/way proto): An inter AS routing proto used on internet, used between & within AS, Determines loops, two BGP neighbors must be on same physical net to communicate, doesn’t use a core, all areas can comm w/o going thro?a core backbone, incremental updates for optimal routes only, metric with degree of preference.
Message Types: Open-conn established, Notification: error det, Keepalive: keeps the hold timer alive,
Novell IPX proto stack : ( SPX Sequence pkt exch, IP Internetwork pkt exch)
7/ 6/ 5-SAP, NCP; 4-SPX; 3-IPX, RIP, NLSP; 2+1-Thro Open Data Link ODL Interface Novell supports all media types.
IPX: connless proto, uses sockets, controls assignment of address ( software addressing), governs pkt delivery, makes routing decisions based on info from RIP or NLSP proto, SPX: adds conn oriented comms to the connless IPX. Works by creating virtual ckts or connections between machines with each conn having a conn ID included in the IPX header.
Novell RIP: dist vect routing proto, uses ticks (1/18 sec) & hop count (max 15) as metrics, split horizon, Aging timer,
RIP Broadcast @ 60 sec, SAP: svce advt proto, servers use it to advt svcs @ 60 sec, nodes use it to locate svcs,
Netware server: SAP(svcs table)& RIP (routing table) info xge between servers by broadcast @ 60 sec,
NLSP: Netware Link svce proto, advanced link state routing proto, might replace RIP & SAP. NCP: Netware core proto, provides file access, printing, synch, & security. GNS Request : Loc server, Cisco router + Rem server (book)
IPX Addressing: use 80 bits (10 bytes), first 4 B-Net add; 6 B-Node add & is assigned autoly, mostly MAC add (3B vendor code +3B sl no- so no need ARP). Since hw MAC add is included as part of software add IPX , no need of ARP eqvlnt.
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