Cisco Notepad

12.12 Telnet Service Options

• Configure R3 to source all telnet sessions from its Loopback0 interface, and to use a marking of IP Precedence 3 for these packets.
• …
• Idle outgoing telnet sessions should signal the remote host to pause output.
• Display the message “Sorry, your connection failed” when a telnet connection to the above host fails.

Configuration

Rack1R3#sh run

service telnet-zeroidle
ip telnet source-interface Loopback0
ip telnet tos 60
ip telnet quiet
ip telnet hidden hostnames
ip telnet hidden addresses

ip host R4 150.1.4.4
busy-message R4 ^CSorry, your connection failed^C

Rack1R3(config)#service ?
  alignment              Control alignment correction and logging
  compress-config        Compress the nvram configuration file
  config                 TFTP load config files
  dhcp                   Enable DHCP server and relay agent
  disable-ip-fast-frag   Disable IP particle-based fast fragmentation
  exec-callback          Enable exec callback
  exec-wait              Delay EXEC startup on noisy lines
  finger                 Allow responses to finger requests
  hide-telnet-addresses  Hide destination addresses in telnet command
  linenumber             enable line number banner for each exec
  nagle                  Enable Nagle's congestion control algorithm
  old-slip-prompts       Allow old scripts to operate with slip/ppp
  pad                    Enable PAD commands
  password-encryption    Encrypt system passwords
  prompt                 Enable mode specific prompt
  pt-vty-logging         Log significant VTY-Async events
  sequence-numbers       Stamp logger messages with a sequence number
  slave-log              Enable log capability of slave IPs
  tcp-keepalives-in      Generate keepalives on idle incoming network
                         connections
  tcp-keepalives-out     Generate keepalives on idle outgoing network
                         connections
  tcp-small-servers      Enable small TCP servers (e.g., ECHO)
  telnet-zeroidle        Set TCP window 0 when connection is idle
  timestamps             Timestamp debug/log messages
  udp-small-servers      Enable small UDP servers (e.g., ECHO)

IEWB1 Vol1 ver5 Task 12.10

• Configure R3 to save core dumps to an FTP server at 155.X.146.100 under the name “r3-core”.
• Use active FTP and the username/password values cisco/cisco.
• Configure the router to generate a memory dump and reload as soon as free memory falls below 1Mbyte.
• The router should also reload in the case that memory fragmentation prohibits a process from allocating more than 64Kbytes of memory.
• Disable the local crash information collection.

Configuration

Rack1R3#
exception core-file r3-core
exception protocol ftp
exception dump 155.1.146.100
exception memory fragment 64000
exception memory minimum 1000000
!
no ip ftp passive
ip ftp username cisco
ip ftp password cisco
!
no exception crashinfo

Note with entering the last command:

Rack1R3(config)#no exception crashinfo
% Incomplete command.

Rack1R3(config)#no exception crashinfo file flash:

Rack1R3(config)#do sh run | in crashinfo
no exception crashinfo