Ipv6 Cisco Training Using The address-family Ipv4 Command
Now, if this is your first time being introduced to the Cisco IOS command named address-family ipv4 youre in for a real treat; because this article is going to quickly explain the command to you; so, without further ado lets 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, lets 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, heres an example:
Router(config-router-af)#
And heres 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 wasnt enough information and you require more; I suggest you visit my website were youll find the latest information regarding Cisco IPv6 Design and Implementation Techniques.
To your success,