address family

Answered Question
Apr 18th, 2007

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

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Correct Answer by Harold Ritter about 9 years 7 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 7 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

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.

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

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

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

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

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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