Hi David,
The AFI represents the Address Family Identifier i.e. it is the primary protocol identifer e.g. IPv4, IPv6,
The SAFI is the Subsequent Address Family Identifier which qualifies the AFI to be of a certain type e.g unicast, multicast
The NLRI is the "prefix" that corresponds to a given AFi/SAFI e.g. 10.1.1.0/24 for IPv4 unicast, 2001:FF::/64 for IPv6.
Here's the current list of AFI's assigned by IANA:
Number Description Reference
------ ---------------------------------------------------- ---------
0 Reserved
1 IP (IP version 4)
2 IP6 (IP version 6)
3 NSAP
4 HDLC (8-bit multidrop)
5 BBN 1822
6 802 (includes all 802 media plus Ethernet "canonical format")
7 E.163
8 E.164 (SMDS, Frame Relay, ATM)
9 F.69 (Telex)
10 X.121 (X.25, Frame Relay)
11 IPX
12 Appletalk
13 Decnet IV
14 Banyan Vines
15 E.164 with NSAP format subaddress [UNI-3.1] [Malis]
16 DNS (Domain Name System)
17 Distinguished Name [Lynn]
18 AS Number [Lynn]
19 XTP over IP version 4 [Saul]
20 XTP over IP version 6 [Saul]
21 XTP native mode XTP [Saul]
22 Fibre Channel World-Wide Port Name [Bakke]
23 Fibre Channel World-Wide Node Name [Bakke]
24 GWID [Hegde]
65535 Reserved
And here's the current list of SAFI:
Value Description Reference
----- ----------- ---------
0 Reserved
1 Network Layer Reachability Information used [RFC2858]
for unicast forwarding
2 Network Layer Reachability Information used [RFC2858]
for mulitcast forwarding
3 Network Layer Reachability Information used [RFC2858]
for both unicast and multicast forwarding
4 Network Layer Reachability Information (NLRI) [RFC3107]
with MPLS Labels
5-63 Unassigned
64 Tunnel SAFI [Nalawade]
65 Virtual Private LAN Service (VPLS) [Kompella]
66 BGP MDT SAFI [Nalawade]
67-127 Unassigned
128 MPLS-labeled VPN address [RFC4364]
129-255 Private Use
Hope that helps - pls rate the post if it does.
Paresh
