3com 3031 Instruccion De Instalación

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C
HAPTER
 60: IPS
EC
 C
ONFIGURATION
Encryption ACLs defined at the local and peer routers must be consistent (i.e., they 
can mirror each other), thus allowing either side to decrypt the data encrypted at 
the other side. For example,
Local end:
acl number 2101
rule 1 permit ip source 173.1.1.1 0.255.255.255 destination 
173.2.2.2 0.255.255.255
Peer end:
acl number 2101
rule 1 permit ip source 173.2.2.2 0.255.255.255 destination 
173.1.1.1 0.255.255.255
IPSec protects the data flow permitted in the ACL, therefore, the users are 
recommended to configure the ACL accurately, that is, configure permit only to 
the data flow needing IPSec protection so as to avoid the excessive use of the key 
word 
any
.
The users are recommended to configure the ACLs of local and peer ends as the 
mirror of each other.
Executing the 
display acl
 command will display all the ACLs, including all the 
extended IP ACLs regardless whether they are for communications filtering or for 
encryption. Simply speaking, the system does not discriminate the extended ACLs 
for these two purposes in the output information of this command.
Defining IPSec Proposal
An IPSec proposal saves the particular security protocol and the 
encryption/authentication algorithms applied in IPSec, intending for providing 
security parameters for IPSec to make SA negotiation. To ensure the success of a 
negotiation, the two ends involved in the negotiation MUST use the same IPSec 
proposal.
Perform the following tasks to configure an IPSec proposal.
Define IPSec proposal
Select security protocol
Select security algorithms
Set the mode adopted by the security protocol in IP datagram encapsulation
Defining IPSec proposal
IPSec proposal is a set of security protocol, algorithms and packet encapsulation 
format used to implement IPSec protection. An IPSec policy can determine the 
adopted security protocol, algorithms, and encapsulation mode by quoting one or 
more IPSec proposals. Before an IPSec proposal is quoted by IPSec policy, this IPSec 
proposal must be established. Up to 50 IPSec proposals can be configured.
You are allowed to modify an IPSec proposal, but such modifications cannot take 
effect at all if the modified proposal is applied to an SA that has been set up 
between the two sides after negotiation - unless you execute the 
reset ipsec sa
 
command to reset the SA. New security proposals can only apply to new SAs.