1-2
Cisco ASA Series CLI Configuration Guide
Chapter 1 Setting General VPN Parameters
Permitting Intra-Interface Traffic (Hairpinning)
The syntax is
sysopt connection permit-vpn
.
The command has no keywords or arguments.
The following example enables IPsec traffic through the ASA without checking ACLs:
hostname(config)#
sysopt connection permit-vpn
Note
Decrypted through-traffic is permitted from the client despite having an access group on the outside
interface, which calls a
deny ip any any
access list, while
no sysopt connection permit-vpn
is
configured.
Users who want to control access to the protected network via site-to-site or remote access VPN using
the
no sysopt permit-vpn
command in conjunction with an access control list (ACL) on the outside
interface are not successful.
In this situation, when management-access inside is enabled, the ACL is not applied, and users can still
connect to the ASA using SSH. Traffic to hosts on the inside network is blocked correctly by the ACL,
but decrypted through-traffic to the inside interface is not blocked.
The
ssh
and
http
commands are of a higher priority than the ACLs. In other words, to deny SSH, Telnet,
or ICMP traffic to the box from the VPN session, use
ssh
,
telnet
and
icmp
commands.
Permitting Intra-Interface Traffic (Hairpinning)
The ASA includes a feature that lets a VPN client send IPsec-protected traffic to another VPN user by
allowing such traffic in and out of the same interface. Also called “hairpinning”, this feature can be
thought of as VPN spokes (clients) connecting through a VPN hub (ASA).
In another application, hairpinning can redirect incoming VPN traffic back out through the same
interface as unencrypted traffic. This would be useful, for example, to a VPN client that does not have
split tunneling but needs to both access a VPN and browse the web.
shows VPN Client 1 sending secure IPsec traffic to VPN Client 2 while also sending
unencrypted traffic to a public web server.
Figure 1-1
VPN Client Using Intra-Interface Feature for Hairpinning
Client VPN
laptop 2
Client VPN
laptop 1
192.168.0.11
192.168.0.10
Unencrypted traffic
Ipsec/SSL encrypted traffic
192.168.0.0
Security
appliance
Public web
server
143170
Содержание 5505 - ASA Firewall Edition Bundle
Страница 28: ...Glossary GL 24 Cisco ASA Series CLI Configuration Guide ...
Страница 61: ...P A R T 1 Getting Started with the ASA ...
Страница 62: ......
Страница 218: ...1 56 Cisco ASA Series CLI Configuration Guide Chapter 1 Managing Feature Licenses Feature History for Licensing ...
Страница 219: ...P A R T 2 Configuring High Availability and Scalability ...
Страница 220: ......
Страница 358: ...1 22 Cisco ASA Series CLI Configuration Guide Chapter 1 Information About Failover Failover Messages ...
Страница 403: ...P A R T 2 Configuring Interfaces ...
Страница 404: ......
Страница 499: ...P A R T 2 Configuring Basic Settings ...
Страница 500: ......
Страница 516: ...1 16 Cisco ASA Series CLI Configuration Guide Chapter 1 Configuring Basic Settings Monitoring DNS Cache ...
Страница 533: ...P A R T 2 Configuring Objects and Access Lists ...
Страница 534: ......
Страница 558: ...1 4 Cisco ASA Series CLI Configuration Guide Chapter 1 Information About Access Lists Where to Go Next ...
Страница 601: ...P A R T 2 Configuring IP Routing ...
Страница 602: ......
Страница 632: ...1 8 Cisco ASA Series CLI Configuration Guide Chapter 1 Defining Route Maps Feature History for Route Maps ...
Страница 680: ...1 48 Cisco ASA Series CLI Configuration Guide Chapter 1 Configuring OSPF Feature History for OSPF ...
Страница 745: ...P A R T 2 Configuring Network Address Translation ...
Страница 746: ......
Страница 780: ...1 34 Cisco ASA Series CLI Configuration Guide Chapter 1 Information About NAT Where to Go Next ...
Страница 844: ...1 32 Cisco ASA Series CLI Configuration Guide Chapter 1 Configuring Twice NAT Feature History for Twice NAT ...
Страница 845: ...P A R T 2 Configuring AAA Servers and the Local Database ...
Страница 846: ......
Страница 859: ...1 13 Cisco ASA Series CLI Configuration Guide Chapter 1 Configuring AAA Servers and the Local Database Configuring AAA ...
Страница 871: ...1 25 Cisco ASA Series CLI Configuration Guide Chapter 1 Configuring AAA Servers and the Local Database Configuring AAA ...
Страница 981: ...P A R T 2 Configuring Access Control ...
Страница 982: ......
Страница 994: ...1 12 Cisco ASA Series CLI Configuration Guide Chapter 1 Configuring Access Rules Feature History for Access Rules ...
Страница 1028: ...1 34 Cisco ASA Series CLI Configuration Guide Chapter 1 Configuring Management Access Feature History for Management Access ...
Страница 1054: ...1 26 Cisco ASA Series CLI Configuration Guide Chapter 1 Configuring AAA Rules for Network Access Feature History for AAA Rules ...
Страница 1060: ...1 6 Cisco ASA Series CLI Configuration Guide Chapter 1 Configuring Web Cache Services Using WCCP Feature History for WCCP ...
Страница 1061: ...P A R T 2 Configuring Service Policies Using the Modular Policy Framework ...
Страница 1062: ......
Страница 1093: ...P A R T 2 Configuring Application Inspection ...
Страница 1094: ......
Страница 1191: ...P A R T 2 Configuring Unified Communications ...
Страница 1192: ......
Страница 1333: ...P A R T 2 Configuring Connection Settings and QoS ...
Страница 1334: ......
Страница 1370: ...1 20 Cisco ASA Series CLI Configuration Guide Chapter 1 Configuring QoS Feature History for QoS ...
Страница 1379: ...P A R T 2 Configuring Advanced Network Protection ...
Страница 1380: ......
Страница 1448: ...1 20 Cisco ASA Series CLI Configuration Guide Chapter 1 Configuring Threat Detection Configuration Examples for Threat Detection ...
Страница 1474: ...1 18 Cisco ASA Series CLI Configuration Guide Chapter 1 Configuring Filtering Services Monitoring Filtering Statistics ...
Страница 1475: ...P A R T 2 Configuring Modules ...
Страница 1476: ......
Страница 1504: ...1 28 Cisco ASA Series CLI Configuration Guide Chapter 1 Configuring the ASA IPS Module Feature History for the ASA IPS module ...
Страница 1528: ...1 24 Cisco ASA Series CLI Configuration Guide Chapter 1 Configuring the ASA CX Module Feature History for the ASA CX Module ...
Страница 1548: ...1 20 Cisco ASA Series CLI Configuration Guide Chapter 1 Configuring the ASA CSC Module Feature History for the CSC SSM ...
Страница 1549: ...P A R T 2 Configuring VPN ...
Страница 1550: ......
Страница 1592: ...1 42 Cisco ASA Series CLI Configuration Guide Chapter 1 Configuring IPsec and ISAKMP Supporting the Nokia VPN Client ...
Страница 1612: ...1 20 Cisco ASA Series CLI Configuration Guide Chapter 1 Configuring L2TP over IPsec Feature History for L2TP over IPsec ...
Страница 1796: ...1 6 Cisco ASA Series CLI Configuration Guide Chapter 1 Configuring the PPPoE Client Using Related Commands ...
Страница 1965: ...P A R T 2 Configuring Logging SNMP and Smart Call Home ...
Страница 1966: ......
Страница 1988: ...1 22 Cisco ASA Series CLI Configuration Guide Chapter 1 Configuring Logging Feature History for Logging ...
Страница 2002: ...1 14 Cisco ASA Series CLI Configuration Guide Chapter 1 Configuring NetFlow Secure Event Logging NSEL Feature History for NSEL ...
Страница 2036: ...1 34 Cisco ASA Series CLI Configuration Guide Chapter 1 Configuring SNMP Feature History for SNMP ...
Страница 2059: ...P A R T 2 System Administration ...
Страница 2060: ......
Страница 2098: ...1 8 Cisco ASA Series CLI Configuration Guide Chapter 1 Troubleshooting Viewing the Coredump ...
Страница 2099: ...P A R T 2 Reference ...
Страница 2100: ......