1-10
Cisco ASA Series CLI Configuration Guide
Chapter 1 Completing Interface Configuration (Routed Mode)
Completing Interface Configuration in Routed Mode
hostname/contextA(config-if)#
nameif outside
hostname/contextA(config-if)#
security-level 100
hostname/contextA(config-if)#
ip address 10.1.2.1 255.255.255.0
What to Do Next
•
(Optional) Configure the MAC address and the MTU. See the
“Configuring the MAC Address and
.
•
(Optional) Configure IPv6 addressing. See the
“Configuring IPv6 Addressing” section on
Configuring the MAC Address and MTU
This section describes how to configure MAC addresses for interfaces and how to set the MTU.
Information About MAC Addresses
By default, the physical interface uses the burned-in MAC address, and all subinterfaces of a physical
interface use the same burned-in MAC address.
For the ASASM, all VLANs use the same MAC address provided by the backplane.
A redundant interface uses the MAC address of the first physical interface that you add. If you change
the order of the member interfaces in the configuration, then the MAC address changes to match the
MAC address of the interface that is now listed first. If you assign a MAC address to the redundant
interface using this command, then it is used regardless of the member interface MAC addresses.
For an EtherChannel, all interfaces that are part of the channel group share the same MAC address. This
feature makes the EtherChannel transparent to network applications and users, because they only see the
one logical connection; they have no knowledge of the individual links. The port-channel interface uses
the lowest numbered channel group interface MAC address as the port-channel MAC address.
Alternatively you can manually configure a MAC address for the port-channel interface. In multiple
context mode, you can automatically assign unique MAC addresses to interfaces, including an
EtherChannel port interface. We recommend manually, or in multiple context mode, automatically
configuring a unique MAC address in case the group channel interface membership changes. If you
remove the interface that was providing the port-channel MAC address, then the port-channel MAC
address changes to the next lowest numbered interface, thus causing traffic disruption.
In multiple context mode, if you share an interface between contexts, you can assign a unique MAC
address to the interface in each context. This feature lets the ASA easily classify packets into the
appropriate context. Using a shared interface without unique MAC addresses is possible, but has some
limitations. See the
“How the ASA Classifies Packets” section on page 1-3
for more information. You
can assign each MAC address manually, or you can automatically generate MAC addresses for shared
interfaces in contexts. See the
“Automatically Assigning MAC Addresses to Context Interfaces” section
to automatically generate MAC addresses. If you automatically generate MAC addresses,
you can use this procedure to override the generated address.
For single context mode, or for interfaces that are not shared in multiple context mode, you might want
to assign unique MAC addresses to subinterfaces. For example, your service provider might perform
access control based on the MAC address.
Information About the MTU
The MTU is the maximum datagram size that is sent on a connection. Data that is larger than the MTU
value is fragmented before being sent.
Summary of Contents for 5505 - ASA Firewall Edition Bundle
Page 28: ...Glossary GL 24 Cisco ASA Series CLI Configuration Guide ...
Page 61: ...P A R T 1 Getting Started with the ASA ...
Page 62: ......
Page 219: ...P A R T 2 Configuring High Availability and Scalability ...
Page 220: ......
Page 403: ...P A R T 2 Configuring Interfaces ...
Page 404: ......
Page 499: ...P A R T 2 Configuring Basic Settings ...
Page 500: ......
Page 533: ...P A R T 2 Configuring Objects and Access Lists ...
Page 534: ......
Page 601: ...P A R T 2 Configuring IP Routing ...
Page 602: ......
Page 745: ...P A R T 2 Configuring Network Address Translation ...
Page 746: ......
Page 845: ...P A R T 2 Configuring AAA Servers and the Local Database ...
Page 846: ......
Page 981: ...P A R T 2 Configuring Access Control ...
Page 982: ......
Page 1061: ...P A R T 2 Configuring Service Policies Using the Modular Policy Framework ...
Page 1062: ......
Page 1093: ...P A R T 2 Configuring Application Inspection ...
Page 1094: ......
Page 1191: ...P A R T 2 Configuring Unified Communications ...
Page 1192: ......
Page 1333: ...P A R T 2 Configuring Connection Settings and QoS ...
Page 1334: ......
Page 1379: ...P A R T 2 Configuring Advanced Network Protection ...
Page 1380: ......
Page 1475: ...P A R T 2 Configuring Modules ...
Page 1476: ......
Page 1549: ...P A R T 2 Configuring VPN ...
Page 1550: ......
Page 1965: ...P A R T 2 Configuring Logging SNMP and Smart Call Home ...
Page 1966: ......
Page 2059: ...P A R T 2 System Administration ...
Page 2060: ......
Page 2098: ...1 8 Cisco ASA Series CLI Configuration Guide Chapter 1 Troubleshooting Viewing the Coredump ...
Page 2099: ...P A R T 2 Reference ...
Page 2100: ......