CCNA Cheat Sheet

TE1

NT2

S

T

NT1

U

S TE2

TA

R

US EU

Mask CIDR Net Host Rng 252 /30 6 2 4 248 /29 5 3 8 240 /28 4 4 16 224 /27 3 5 32 192 /26 2 6 64 128 /25 1 7 128 0 /24 0 8 0

Ports

Protocol

21 22 23 25 53 69 110 119 161

FTP SSH Telnet SMTP DNS TFTP POP3 NNTP SNMP

80: HTTP 443: HTTPS

TCP

TCP Both!

UDP

Protocol Type EIGRP Hybrid

Admin Dist 90

Metrics

Notes

Multiple 32-bit composite

IGRP

DistVector 

100

Bandwidth, Delay

OSPF

Linkstate DistVector 

110

Bandwidth

Classless, VLSM, DUAL, RTP, PDMs (1x table set per prot), multiple AS#s, mult L3 prots, summarization Cisco prop, 255 max-hop-ct (100 default), AS#, updates @90 sec, invalid @270 sec, hold-down 280 secs, flush 630 secs, classless, VLSM Dijkstra alg, classless (VLSM), wildcard mask

120

Hop count

RIPv1

7 6 5 4 3 2 1

OSI Layer Application Presentation Session Transport Network Data Link Physical

IP Classes A 1 – 126 B 128 – 191 C 192 – 223

PDU Data Data Data Segment Packet Frame Bits

classful, 30 sec updates,180 sec route invalid,240 sec route flush, max. 15 hops (Bellman-Ford alg), round-robin load balancing (max. 6 links)

Internet Layer 4 Application

Internet layer Protocols SNMP, Telnet, FTP, TFTP

3 Transport 2 Internetwork 1 Network Interface

TCP, UDP IP, OSPF, RIP, ICMP lower-layer protocol standards

Private IPs 10.0.0.0 – 10.255.255.255 172.16.0.0 – 172.31.255.255 192.168.0.0 – 192.168.255.255

Dialer map steps: 1. dialer   2. map 3. 4. 5. dial-string

Blocking Listening Learning Forwardin g

DDR dialing sequence: 1. route determination 2. ID interesting traffic 3. Dialer info lookup 4. Traffic txn 5. Call terminated/timed out Standard ACL: Cisco(config)#access-list <1-99> Cisco(config)#access-list <1-99> permit any Extended ACL: Cisco(config)#access-list <100-199> eq Cisco(config)#access-list <100-199> permit any any To apply ACL: Cisco(config-if)#ip access-group <#> Applying IP address to 2950 switch: (config)#interface vlan1 ip address no shut Configure a new switch

SW2#Vlan database SW2#vtp domain fred SW2#exit set-up Client Trunking

SW2(conf)#int fa0/11 SW2(conf-if)#switch mode dynamic auto SW2(conf-if)#^Z SW2# Trouble Shooting Domain name must be the same One switch must be server (switch mode dynamic desirable) The others must be clients (switch mode dynamic auto)

STP States Preventing use of looped paths Prep to forward w/o populating MAC table Populate MAC table, not forwarding Sending/rcving data frames DDR Configuration BRI ( min config, switch-type and spid )

RT#isdn switch-type basic-ni1 Defining Interesting Traffic

RT1#access-list 101 permit tcp any host 172.16.3.1 eq 80 ! RT1#dialer-list 1 protocol ip permit ! RT#dialer-list 2 protocol ip list 101 RT#int bri 0 RT#(conf-if)encap ppp RT#(conf-if)ip address 172.16.2.2 255.255.255.0 RT#(conf-if)isdn spid1 555555522222202 (if required) !use this one if all IP is considered interesting RT#(conf-if)dialer-group 1 !or use next statement to trigger web to RT#(conf-if)dialer-group 2 NOTE: only one dialer group per interface!! Dailing: RT#(conf-if)dialer string 17067924567 !or if using broadcast names/ip map RT#(conf-if)dialer map ip 172.16.2.2 broadcast name LA 17212345555 DDR Configuration PRI Must configure: switch-type, DSO channels, encoding & framing, Configure a Default Route ip route 0.0.0.0 0.0.0.0 192.1.1.6 ip route default-network 10.0.0.0 (used to reach another Class A,B, or C network by default) Frame-Relay Static Mapping no frame-relay inverse-arp frame-relay map ip 199.1.1.2 570 broadcast frame-relay map ip 199.1.1.3 571 broadcast Dynamic frame-relay interface-dlci 570 [lim type]

Simulation Tips 1. Id Problem/Understand Topology 2. Watch the time 3. Use organized Troubleshooting 4. Things to look for: - Network Statements - IP a ddressing/Mask  - VTY Passwords

Point-to-Point (inverse ARP not needed) interface serial 0.3 point-to-point ip address 123.45.6.7 255.255.0.0 frame-relay interface-dlci 570