TechTutorials - Free Computer Tutorials  







IPv6 Training (Cisco): Using the “address-family ipv4” Command 
 


Added: 11/10/2008, Hits: 6,949, Rating: 0, Comments: 0, Votes: 0
Add To Favorites | Comment on this article
Now, if this is your first time being introduced to the Cisco IOS command named “address-family ipv4” you’re in for a real treat; because this article is going to quickly explain the command to you; so, without further ado let’s begin.

The ““address-family ipv4” command is mainly used for BGP Multi-Topology Routing or (MTR); network administrators (like you) use the command to configure a BGP routing session that uses standard IPv4 address prefixes. The command can be performed in either Router Configuration Mode (Router(config-router)#address-family ipv4 ) Or Router Scope Configuration Mode (Router(config-router-scope)#address-family ipv4).

Here is the syntax you can use when the router is in Router Configuration Mode:

address-family ipv4 [mdt | multicast | tunnel | unicast [vrf vrf-name] | vrf vrf-name]

And, here is the syntax you can use when the router in Router Scope Configuration Mode:

address-family ipv4 [mdt | multicast | unicast]

So, after typing in the desired syntax, and hitting (pressing) the Enter key; the router will enter into either “Router Configuration Address Family Configuration Mode” Or “Router Scope Configuration Address Family Configuration Mode”.

Now, let’s say, you used the “address-family ipv4” earlier on a router and now you need to remove the IPv4 address family configuration from the (your) running configuration (running-config) file, and also exit address family configuration mode, you can perform both tasks by simply typing the word “no” in front of the command like this:

Example in Router Configuration Mode:

Router(config-router)#no address-family ipv4

Example in Router Scope Configuration Mode:

Router(config-router-scope)#no address-family ipv4

Explanation of the “address-family ipv4” command keywords:

mdt – Is an optional keyword; that can be used to specify an IPv4 Multicast Distribution tree (MDT) address-family session.

multicast – Is an optional keyword; that can be used to specify IPv4 multicast address prefixes.

tunnel – Is an optional keyword; that can be used to specify an IPv4 routing session for multipoint tunneling.

unicast – Is an optional keyword; that can be used to specify IPv4 unicast address prefixes (by the way, this is default).

vrf vrf-name – Is an optional keyword; that can be used to specify the name of the VPN routing and forwarding (VRF) instance to associate with subsequent IPv4 address family configuration mode commands.

Lastly, just in case if you were wondering, what the router prompt looks like when a Cisco router is in “Router Configuration Address Family Configuration Mode, here’s an example:

Router(config-router-af)#

And here’s an example of what the router prompt looks like when a Cisco router is in “Router Scope Configuration Address Family Configuration Mode”:

Router(config-router-scope-af)#

I wrote this article to help you quickly understand the usage and keywords that are associated with the “address-family ipv4” command; if after reading this article you feel this wasn’t enough information and you require more; I suggest you visit my website were you’ll find the latest information regarding Cisco IPv6 Design and Implementation Techniques.

To your success,

Charles Ross
CCNP #CSCO10444244
http://www.ciscoipv6ittechtips.com





Comments (0)

Be the first to comment on this article


Related Items








7 Seconds Resources, Inc.




IT Showcase