address family

Answered Question
Apr 18th, 2007
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hello. anybody know when address family first time appeared.... what is exactly purpose of address family? is true this is exists in rip,ospf,eigrp,bgp? is bgp address family only used on mpls? thanks

Correct Answer by Harold Ritter about 9 years 11 months ago

Mohammed,


You can add a few more:


RouterB(config-router)#address-family ?

ipv4 Address family

ipv6 Address family

l2vpn Address family

nsap Address family

vpnv4 Address family

vpnv6 Address family

RouterB(config-router)#address-family ipv4 ?

mdt Address Family modifier

multicast Address Family modifier

tunnel Address Family modifier

unicast Address Family modifier

vrf Specify parameters for a VPN Routing/Forwarding instance



- "ipv4 mdt" is for MDT SAFI support (mVPN InterAS support)

http://www.cisco.com/en/US/products/sw/iosswrel/ps1829/products_feature_guide09186a00803420bc.html

- "ipv4 tunnel" is for Tunnel SAFI support (mpls vpn over IP Tunnels)

http://www.cisco.com/en/US/products/sw/iosswrel/ps1829/products_feature_guide09186a00802b4817.html

- "l2vpn vpls" is for VPLS auto-discovery support.

http://www.cisco.com/univercd/cc/td/doc/product/software/ios122sr/newft/122srb33/fs_vpls.htm

- "nsap" is for CLNS support.

http://www.cisco.com/en/US/products/ps6441/products_configuration_guide_chapter09186a00807f6ff5.html

- "vpnv6" is for 6VPE (ipv6 mpls vpn) support.

http://www.cisco.com/en/US/products/sw/iosswrel/ps5187/products_configuration_guide_chapter09186a00807d26c0.html



Hope this helps,

Correct Answer by mohammedmahmoud about 9 years 11 months ago

Hi Jimmy,


Been along time, but going through the posts i found out that i didn't answer all your points, as for the part "is bgp address family only used on mpls?"


BGP supports the following address-families:


IPv4 unicast

address-family ipv4 unicast


IPv4 multicast

address-family ipv4 multicast


IPv6 unicast

address-family ipv6 unicast


VPN-IPv4 unicast

address-family vpnv4 unicast


VPN-IPv4 multicast

address-family vpnv4 multicast


IPv4 unicast with CE router

address-family ipv4 vrf vrf-name



HTH,

Mohammed Mahmoud.

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Overall Rating: 4.3 (4 ratings)
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mohammedmahmoud Thu, 04/19/2007 - 00:48
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Hi there,


The concept of address-family (routing context) was introduced to enhance the peer-to-peer VPN Model (the current perfect example is MPLS VPNs).


Each VPN is associated with a VPN routing/forwarding instances (VRFs). A VRF table defines a VPN at a customer site attached to a PE router. A VRF table consists of:


* an IP routing table

* a derived Cisco Express Forwarding (CEF) table

* a set of interfaces that use the forwarding table

* a set of rules and routing protocol variables that determine what goes into the forwarding table


Although VRF provides isolation on PE routers between customers, the customers routes needs to be propagated to other PEs for customer site to site reachability --> A routing process is needed between each CE and its PE and also between PE routers while still providing isolation (VPN aware routing protocols)


Since the router can run a limited number of routing protocols (ex: A router can run only 1 instance of RIP and BGP), and since each VPN (more precisely each VRF) requires isolated routing table --> (for both security and address space overlapping) --> These protocols can't run directly in their native form as a PE-CE routing protocol.


Routing Context = Routing Protocol per VRF = address-families


This can be implemented in 2 ways:

. Several instances of the same routing process or simply address-family (BGP, RIP v2 and EIGRP) - Each instance will contain its own independent parameters (networks/timers/neighbors/auth/...)

. Several routing processes (OSPF)


NOTE: ISIS is not a VPN-aware routing protocol --> It doesn't support address-family, and OSPF is a VPN-aware routing protocol but using another concept than address-family (it uses a separate OSPF process per VRF).


HTH, please rate if it does,

Mohammed Mahmoud.

Paolo Bevilacqua Thu, 04/19/2007 - 06:26
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I could not explain this better, even if I knew (and is not the case :)

My rate a "5" !

mohammedmahmoud Thu, 04/19/2007 - 14:30
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Hi there,


Thanks Paolo :)


Jimmy, I forgot to add that VRF-Lite also supports address-families but only BGP, RIP and Static routing can operate between the PE and the CE routers (OSPF has also added the support for Multi-VRF on CE Routers).


HTH,

Mohammed Mahmoud.


mohammedmahmoud Fri, 04/20/2007 - 01:05
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Hi Jimmy,


If you can acquire "MPLS Fundamentals by Luc De Ghein, CCIE No. 1897" book it would be great, i've used this book and i've benefited a lot from it.


BR,

Mohammed Mahmoud.

Correct Answer
mohammedmahmoud Mon, 04/23/2007 - 06:52
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  • Green, 3000 points or more

Hi Jimmy,


Been along time, but going through the posts i found out that i didn't answer all your points, as for the part "is bgp address family only used on mpls?"


BGP supports the following address-families:


IPv4 unicast

address-family ipv4 unicast


IPv4 multicast

address-family ipv4 multicast


IPv6 unicast

address-family ipv6 unicast


VPN-IPv4 unicast

address-family vpnv4 unicast


VPN-IPv4 multicast

address-family vpnv4 multicast


IPv4 unicast with CE router

address-family ipv4 vrf vrf-name



HTH,

Mohammed Mahmoud.

Correct Answer
Harold Ritter Mon, 04/23/2007 - 07:22
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  • Cisco Employee,

Mohammed,


You can add a few more:


RouterB(config-router)#address-family ?

ipv4 Address family

ipv6 Address family

l2vpn Address family

nsap Address family

vpnv4 Address family

vpnv6 Address family

RouterB(config-router)#address-family ipv4 ?

mdt Address Family modifier

multicast Address Family modifier

tunnel Address Family modifier

unicast Address Family modifier

vrf Specify parameters for a VPN Routing/Forwarding instance



- "ipv4 mdt" is for MDT SAFI support (mVPN InterAS support)

http://www.cisco.com/en/US/products/sw/iosswrel/ps1829/products_feature_guide09186a00803420bc.html

- "ipv4 tunnel" is for Tunnel SAFI support (mpls vpn over IP Tunnels)

http://www.cisco.com/en/US/products/sw/iosswrel/ps1829/products_feature_guide09186a00802b4817.html

- "l2vpn vpls" is for VPLS auto-discovery support.

http://www.cisco.com/univercd/cc/td/doc/product/software/ios122sr/newft/122srb33/fs_vpls.htm

- "nsap" is for CLNS support.

http://www.cisco.com/en/US/products/ps6441/products_configuration_guide_chapter09186a00807f6ff5.html

- "vpnv6" is for 6VPE (ipv6 mpls vpn) support.

http://www.cisco.com/en/US/products/sw/iosswrel/ps5187/products_configuration_guide_chapter09186a00807d26c0.html



Hope this helps,

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