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--- who_is_using_this_ip_address [2014/01/11 15:24] – samer
+++ who_is_using_this_ip_address [2014/02/09 13:04] – [3- A Do-It-Yourself BGP Query Service] samer
@@ Line 1: / Line 1: @@
+====== Who is Using This IP Address? =====
 A frequent question that faces network administrators or application developers consists in identifying //who is using a specific public IP address//. This information can be utilized for instance to perform user localization and enable location-based services or user access control. In this context, a main technical challenge is to associate the IP address or prefix with its corresponding Autonomous System (AS).
-====== Limitations of the whois Information ======
+===== -- Limitations of the whois Information =====
-A typical method to identify the AS that announces a specific IP prefix is to use the whois protocol. A whois command is available on main OSes and enables to query the databases of regional registries such as ARIN, RIPE, LACNINC, ... A very interesting [[http://answers.oreilly.com/topic/408-how-to-use-and-understand-whois-in-its-many-forms | article]] provides tips for using the whois command. Here is a simple example that queries the whois.ripe.net server database in order to find the origin AS of the 148.60.0.0/16.
+A typical method to identify the AS that announces a specific IP prefix is to use the whois protocol. A whois command is available on main OSes and enables to query the databases of regional registries such as ARIN, RIPE, LACNINC, ... A very interesting [[http://answers.oreilly.com/topic/408-how-to-use-and-understand-whois-in-its-many-forms | article]] provides tips for using the whois command. Here is a simple example that queries the whois.ripe.net server database in order to find the origin AS of the ''148.60.0.0/16''.
 	$ whois -h whois.ripe.net 148.60.0.0/16 | grep origin
 	origin:         AS2200
-However things get complicated very rapidly since the route object information is not always provided or may be outdated. Trying for example to identify the AS announcing 203.178.141.194 (corresponding to the famous www.kame.net), no answer is obtained since the corresponding route object is not registered by WIDE.
+However things get complicated very rapidly since the route object information is not always provided or may be outdated. Trying for example to identify the AS announcing ''203.178.141.194'' (corresponding to the famous www.kame.net), no answer is obtained since the corresponding route object is not registered by WIDE.
 	$ whois -h whois.apnic.net 203.178.141.194 | grep origin
-====== Using BGP Information ======
+===== -- Using BGP Information =====
-An alternative method for identifying the AS that announces a specific IP prefix consists in studying the BGP routing information. Typically, each BGP speaking router stores in a BGP table the routing announcements received for each prefix together with some protocol attributes such as the AS-PATH. This attribute contains the list of ASes traversed by the BGP announcement, with the first AS being the origin AS for the IP prefix! Therefore, the problem boils down to parsing the BGP routing information, matching the IP address or prefix, and then extracting the origin AS from the AS-PATH attribute. Such process is obviously optimal when the router has a global view of the Internet: this is the case for routers participating in the Default Free Zone (DFZ) where the BGP tables contain *all the prefixes* announced in the Internet. As of 2014, these routers have around 500 000 active BGP entries according to the latest statistics.
+An alternative method for identifying the AS that announces a specific IP prefix consists in studying the BGP routing information. Typically, each BGP speaking router stores in a BGP table the routing announcements received for each prefix together with some protocol attributes such as the AS-PATH. This attribute contains the list of ASes traversed by the BGP announcement, with the first AS being the origin AS for the IP prefix! Therefore, the problem boils down to parsing the BGP routing information, matching the IP address or prefix, and then extracting the origin AS from the AS-PATH attribute. Such process is obviously optimal when the router has a global view of the Internet: this is the case for routers participating in the Default Free Zone (DFZ) where the BGP tables contain //all the prefixes// announced in the Internet. As of 2014, these routers have around 500 000 active BGP entries according to the latest statistics.
 [{{ :bgp-table.png?direct&600 | Figure 1. Active BGP entries}}]
-However, having access to a DFZ BGP router is not easy in practice. Alternatively, it is possible to find similar routing information on looking glasses or route servers that are made public by network operators (see for example a list of servers on [[routeserver.org]]. Such devices are originally deployed in order to contribute to the monitoring or the tracking of BGP anomalies in the Internet.
+However, having access to a DFZ BGP router is not easy in practice. Alternatively, it is possible to find similar routing information on looking glasses or route servers that are made public by network operators (see for example a list of servers on www.routeserver.org). Such devices are originally deployed in order to contribute to the monitoring or the tracking of BGP anomalies in the Internet.
-Let us try for example to log on the Allstream route server in Canada and identify the origin AS of 148.60.0.0/16. The output of the ''show ip bgp command'' shows the AS path "15290 3356 1273 2200" in the BGP announcements. Therefore, the first AS, *i.e.*, 2200 is the origin AS of the studied prefix.
+Let us try for example to log on the Allstream route server in Canada and identify the origin AS of ''148.60.0.0/16''. The output of the ''show ip bgp command'' shows the AS path ''15290 3356 1273 2200'' in the BGP announcements. Therefore, the first AS, //i.e.//, AS ''2200'' is the origin AS of the studied prefix.
 	$ telnet route-server.east.bb.allstream.net
@@ Line 42: / Line 45: @@
 	      Community: 15290:3356 15290:64995 15290:65050 15290:65506
-Despite its availabitlity, this method remains cumbersome, especially if you want to quickly look up something or if you have a large number of addresses that you want to analyze with a script. Fortunatly, RIPE NCC and Team Cymru have already answered these questions: they provide solutions that combine the versatility of the whois protocol with the accuracy of the BGP information. In other words, you keep on using the legacy whois command by you get BGP-based results. Let us examine these solutions:
+Despite its availability, this method remains cumbersome, especially if you want to quickly look up something or if you have a large number of prefixes that you want to analyse with a script. Fortunately, RIPE NCC and Team Cymru have already answered these questions: they provide solutions that combine the versatility of the whois protocol with the accuracy of the BGP information. In other words, you keep on using the legacy whois command but you get BGP-based results.
+==== -- Team Cymru whois Server ====
+Team Cymru implements the ''whois.cymru.com'' server which provides the announcing AS number and name for any given IP prefix. The information in its database is based on the BGP feeds from 50+ BGP peers, and is updated at 4 hour intervals. Here is a simple example for using the cymru service:
+<code>
+$ whois -h whois.cymru.com 148.60.0.0/16
+AS      | IP               | AS Name
+    | 148.60.0.0       | FR-RENATER Reseau National de telecommunications pour la Technologie
+</code>
+and another example that demonstrates the possibility of sending multiple prefixes in the same query:
+<code>
+$ whois -h whois.cymru.com 148.60.0.0/16 203.178.141.194
+AS      | IP               | AS Name
+    | 148.60.0.0       | FR-RENATER Reseau National de telecommunications pour la Technologie
+AS      | IP               | AS Name
+    | 203.178.141.194  | WIDE-BB WIDE Project
+</code>
+==== -- Riswhois Server ====
+RIPE NCC implements a similar whois service named RISwhois by providing a higher level view over the most recently collected set of routing tables from the Remote Route Collectors (RRCs) at different [[http://www.ripe.net/data-tools/stats/ris/ris-peering-policy | locations]] in the world. Given an IPv4 or IPv6 prefix, RISwhois will tell which prefixes and origin ASes on which RRCs match that particular IP.
+<WRAP info>
+As mentioned on the [[http://www.ripe.net/data-tools/stats/ris/riswhois | Riswhois]] website, BGP information is more accurate than that contained in the databases of the regional registries: 21% of a set of unique IPs were unmatched when using the routing registry vs. only 1% unmatched when using RIS data.
+</WRAP>
+In the following, a simple example shows the output of a Riswhois query: ''203.178.141.194'' is originated by AS ''2500'' as seen by 16 RRCs.
+<code>
+$ whois -h riswhois.ripe.net 203.178.141.194
+route:        203.178.128.0/17
+origin:       AS2500
+descr:        WIDE-BB WIDE Project
+lastupd-frst: 2014-01-23 12:42Z  202.249.2.185@rrc06
+lastupd-last: 2014-02-08 13:26Z  187.16.218.21@rrc15
+seen-at:      rrc00,rrc01,rrc03,rrc04,rrc05,rrc06,rrc07,rrc10,rrc11,rrc12,rrc13,rrc14,rrc15
+num-rispeers: 105
+source:       RISWHOIS
+</code>
+<WRAP round important>
+Due to BGP policies between ASes in the Internet, RRCs may receive different BGP information for the same IP prefix. Therefore, Riswhois provides multiple matchings for the IP prefix, as in the following example. In such cases, a longest prefix matching may help in choosing a single originating AS.
+</WRAP>
+<code>
+$ whois -h riswhois.ripe.net 217.70.184.1
+route:        217.0.0.0/8
+origin:       AS3303
+descr:        SWISSCOM Swisscom (Switzerland) Ltd
+lastupd-frst: 2014-01-30 00:20Z  217.29.66.120@rrc10
+lastupd-last: 2014-02-04 14:36Z  192.65.185.243@rrc04
+seen-at:      rrc04,rrc10
+num-rispeers: 2
+source:       RISWHOIS
-- Team Cymru implements the `whois.cymru.com` server
+route:        217.70.176.0/20
+origin:       AS29169
+descr:        GANDI-AS Gandi SAS
+lastupd-frst: 2013-10-21 08:55Z  202.249.2.185@rrc06
+lastupd-last: 2014-02-08 13:28Z  187.16.218.21@rrc15
+seen-at:      rrc00,rrc01,rrc03,rrc04,rrc05,rrc06,rrc07,rrc10,rrc11,rrc12,rrc13,rrc14,rrc15
+num-rispeers: 111
+source:       RISWHOIS
+</code>
+===== -- A Do-It-Yourself BGP Query Service =====
+When accessing the online servers (Riswhois, Cymru or legacy whois servers) is not possible or not recommended, an autonomous implementation of an equivalent server is possible. This can be the case when service availability constraints are very tight or when the Internet connection is not permanent.
+Here are some hints and recipes to implement a server that maps IP prefixes with AS numbers based on BGP information.
-has made a whois server available which provides the announcing AS number and name for any given IP address. The information in its database is based on 17 BGP feeds and is updated twice per hour. If your operating system has a command-line whois client, simply type `whois -h whois.cymru.com` followed on the same line by the IP address you would like to look up. In addition to simple lookups as described above, the server also supports comments and multiple addresses per query. Both of these features are especially useful if you have a script to analyze a large number of IP addresses from a script. For more information about these features, see the server's web page or type `whois -h whois.cymru.com help`.
+==== Basic Steps ====
-- A similar service was announced by the RIPE RIS project. Their whois server can be queried using "whois -h riswhois.ripe.net", and returns results in RPSL like format (as used by the RIPE whois database itself). The data is gathered from route collector boxes in various locations. For more information about this service, see this web page.
+Start by downloading raw BGP data collected by RIPE NCC servers from http://www.ripe.net/data-tools/stats/ris/ris-raw-data. For example, the latest data file from RRC0 (Amsterdam) is always available on http://data.ris.ripe.net/rrc00/latest-bview.gz.
-	$ whois -h riswhois.ripe.net 217.70.180.132
+<code>
-	% This is RIPE NCC's Routing Information Service
+$ wget http://data.ris.ripe.net/rrc00/latest-bview.gz
-	% whois gateway to collected BGP Routing Tables
+</code>
-	% IPv4 or IPv6 address to origin prefix match
-	%
-	% For more information visit http://www.ripe.net/ris/riswhois.html
-	route:        192.0.0.0/3
-	origin:       AS3303
-	descr:        SWISSCOM Swisscom (Switzerland) Ltd
-	lastupd-frst: 2013-11-09 23:48Z  192.65.185.140@rrc04
-	lastupd-last: 2013-11-09 23:48Z  192.65.185.243@rrc04
-	seen-at:      rrc04
-	num-rispeers: 2
-	source:       RISWHOIS
-	route:        217.0.0.0/8
-	origin:       AS3303
-	descr:        SWISSCOM Swisscom (Switzerland) Ltd
-	lastupd-frst: 2013-09-24 09:23Z  217.29.66.120@rrc10
-	lastupd-last: 2013-11-09 23:48Z  192.65.185.243@rrc04
-	seen-at:      rrc04,rrc10
-	num-rispeers: 3
-	source:       RISWHOIS
-	route:        217.70.176.0/20
-	origin:       AS29169
-	descr:        GANDI-AS Gandi SAS
-	lastupd-frst: 2013-07-04 02:06Z  198.32.176.24@rrc14
-	lastupd-last: 2013-11-11 15:53Z  195.69.146.99@rrc03
-	seen-at:      rrc00,rrc01,rrc03,rrc04,rrc05,rrc06,rrc07,rrc10,rrc11,rrc12,rrc13,rrc14,rrc15
-	num-rispeers: 114
-	source:       RISWHOIS
+As raw data is written in MRT format, you need to install [[https://bitbucket.org/ripencc/bgpdump/wiki/Home | bgpdump]] in order to parse it easily.
-### A Do-It-Yourself BGP Query Service
+<code>
+$ zcat latest-bview.gz | bgpdump -m - > latest-bview-parsed.txt
+</code>
-Start by downloading multiple routing tables for routeviews or RIPE RIS servers. Transform these tables into parsable format bu using bgpdump. Use any scripting language to perform a best prefix match and output the origin AS of your desired IP prefix.
+Use any scripting language to perform a best prefix match and output the origin AS of your desired IP prefix.