cisco默认配置

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　　> no service pad
　　switch off pad protocol on the router.
　　Packet Assembly and Disassembly (PAD) is used for sending and
　　receiving "raw" data over IP networks. The modem takes care of
　　establishing IP network connections, as well as the encapsulation
　　of data within UDP or TCP packets. This eliminates the need for a
　　TCP/IP stack running on the host device.
　　> service timestamps debug uptime
　　switch on the service of timestamping each debug log (when you type any
　　debug command) the router produces.
　　But in opposed to "datetime" you use "uptime".
　　> service timestamps log datetime
　　The same what above, but applied to regular log data.
　　> service password-encryption
　　switch on cisco algorithm to hide clear text password (enable, telnet etc)
　　and instead show this password as a meaningless string (ggtrg9543ygtrhth).
　　In opposed to hash algorithm (e.g. MD5) its eassy to decipher this string to
　　original password.
　　> service sequence-numbers
　　To enable visible sequence numbering of system logging messages, use the
　　service sequence-numbers command in global configuration mode.
　　Each system status messages logged in the system logging process have a
　　sequence reference number applied. This command makes that number visible by
　　displaying it with the message. The sequence number is displayed as the
　　first part of the system status message.
　　For example:
　　000066: .Mar 22 15:35:57 PST: %SYS-5-CONFIG_I: Configured from console by
　　console
　　> no aaa new-model
　　You do not going to use AAA model (authentication, authorization and
　　accounting).
　　> clock timezone UTC 1
　　You set UTC time zone.
　　UTC is Coordinated Universal Time.
　　"1" after UTC means one hour shift, i.e. this is UTC+1=CET (and some others,
　　BST, IST, WEST)
　　CET is Central European Time.
　　> clock summer-time UTC recurring last Sun Mar 2:00 last Sun Oct 3:00
　　Configure the system to automatically switch to summer time (daylight saving
　　time).
　　> ip subnet-zero
　　You want to save and use the first subent (subnet zero).
　　This sybnet has the same network address what main network (the subnetted
　　one) but longer subnet mask
　　For example:
　　10.0.0.0/8 is main network
　　10.0.0.0/24 is subnet zero of this network.
　　With the commands "no ip subnet-zero" You are not allowed to use this
　　subnet.
　　Then You can use 10.0.1.0/24 subnet as the first usable subnet.
　　> no file verify auto
　　switch off automatic verification of cisco files.
　　When You copy some files to your router its safe to verify theirs control
　　sum.
　　For example:
　　copy /verify tftp://10.1.1.1/jdoe/c7200-js-mz disk0:
　　verify disk0:c7200-js-mz
　　reload /verify
　　With this feature switch on You do not need to do this, insted router do
　　this automatically.
　　> spanning-tree mode pvst
　　You want to run pvst (per-Vlan spannig tree) mode od spanning tree protocol.
　　It means that in every vlan throughout your switched network
　　seperate instance of STP frames will be running. Its good only for small
　　number of vlans. In other cases its safe to use MST (multiple spanning tree)
　　> spanning-tree extend system-id

　　Enable the extended system>　　addresses.Releases 12.1(13)E and later support chassis with 64 or 1024 MAC
　　addresses. For chassis with 64 MAC addresses, STP uses the extended system

　　ID plus a MAC address to make the bridge>　　> vlan internal allocation policy ascending
　　It configures the Internal Vlan allocation policy. You can choose between
　　"ascending" and "descending".
　　Enter the ascending keyword to allocate internal VLANs from 1006 and up.
　　Enter the descending keyword to allocate internal VLAN from 4094 and down.
　　1006-4094 - this is extended range of etherenet-only vlans, they are not
　　propagated by vtp protocol.
　　> control-plane
　　switch on control plane policing.
　　The Control Plane Policing feature allows users to configure a quality of
　　service (QoS) filter that manages the traffic flow of control plane packets
　　to protect the control plane of Cisco IOS routers and switches against
　　reconnaissance and denial-of-service (DoS) attacks. In this way, the control
　　plane (CP) can help maintain packet forwarding and protocol states despite
　　an attack or heavy traffic load on the router or switch.