Routing Enumeration

One of the cooler sections in Extreme Exploits covers ways to learn about a target network by looking at routes to those networks. I showed a few ways to use this data two years ago, but here's a more recent example.

Let's say I want to find out more about the organization hosting the Extreme Exploits Web site. First I resolve the hostname to an IP address.

host www.extremeexploits.com
www.extremeexploits.com has address 69.16.147.21

Now I use whois to locate the owner's netblock.

whois 69.16.147.21
Puregig, Inc. PUREGIG1 (NET-69-16-128-0-1)
                                  69.16.128.0 - 69.16.191.255
VOSTROM Holdings, Inc. PUREGIG1-VOSTROM1 (NET-69-16-147-0-1)
                                  69.16.147.0 - 69.16.147.255

# ARIN WHOIS database, last updated 2005-08-14 19:10
# Enter ? for additional hints on searching ARIN's WHOIS database.

Now I telnet to a route server and make queries about this netblock.

route-server.phx1>sh ip bgp 69.16.147.0
BGP routing table entry for 69.16.147.0/24, version 84120350
Bestpath Modifiers: always-compare-med, deterministic-med
Paths: (2 available, best #2)
  Not advertised to any peer
  22822 11588, (received & used)
    67.17.64.89 from 67.17.81.24 (67.17.81.24)
      Origin IGP, metric 0, localpref 300, valid, internal
      Community: 3549:4044 3549:30840 22822:4012 22822:9120
      Originator: 67.17.80.225, Cluster list: 0.0.0.11
  22822 11588, (received & used)
    67.17.64.89 from 67.17.80.251 (67.17.80.251)
      Origin IGP, metric 0, localpref 300, valid, internal, best
      Community: 3549:4044 3549:30840 22822:4012 22822:9120
      Originator: 67.17.80.225, Cluster list: 0.0.0.11

I learn a few details:

• The autonomous system for this network is truly a /24, as shown by "BGP routing table entry for 69.16.147.0/24"


• The AS number for 69.16.147.0/24 is 11588. Its upstream provider AS is 22822. (AS data is read right-to-left.)
  

Now I want to find out if any other networks belong to this AS.

route-server.phx1>sh ip bgp regexp _11588$
BGP table version is 97334640, local router ID is 67.17.81.28
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete

   Network          Next Hop            Metric LocPrf Weight Path
* i63.78.12.0/22    67.17.64.89              0    300      0 22822 11588 i
*>i                 67.17.64.89              0    300      0 22822 11588 i
* i69.16.128.0/19   67.17.64.89              0    300      0 22822 11588 i
*>i                 67.17.64.89              0    300      0 22822 11588 i
* i69.16.147.0/24   67.17.64.89              0    300      0 22822 11588 i
*>i                 67.17.64.89              0    300      0 22822 11588 i
* i69.16.187.0/24   67.17.64.89              0    300      0 22822 11588 i
*>i                 67.17.64.89              0    300      0 22822 11588 i
* i69.16.191.0/24   67.17.64.89              0    300      0 22822 11588 i
*>i                 67.17.64.89              0    300      0 22822 11588 i
* i140.99.96.0/19   67.17.64.89              0    300      0 22822 11588 i
*>i                 67.17.64.89              0    300      0 22822 11588 i
* i208.247.17.0     67.17.64.89              0    300      0 22822 11588 i
*>i                 67.17.64.89              0    300      0 22822 11588 i
* i209.50.48.0/20   67.17.64.89              0    300      0 22822 11588 i
*>i                 67.17.64.89              0    300      0 22822 11588 i
* i209.50.56.0/21   67.17.64.89              0    300      0 22822 11588 i
   Network          Next Hop            Metric LocPrf Weight Path
*>i                 67.17.64.89              0    300      0 22822 11588 i

We could then run queries on the new networks to learn more about them, e.g.:

whois 63.78.12.0
UUNET Technologies, Inc. UUNET63 (NET-63-64-0-0-1)
                                  63.64.0.0 - 63.127.255.255
ElDorado Sales, Inc. UU-63-78-12 (NET-63-78-12-0-1)
                                  63.78.12.0 - 63.78.15.255

# ARIN WHOIS database, last updated 2005-08-14 19:10

One final cool tool: Victor has a project called Pwhois that provides prefix query information:

whois -h whois.pwhois.org 69.16.147.21
IP: 69.16.147.21
Origin-AS: 11588
Prefix: 69.16.147.0/24
AS-Path: 3356 11588
Cache-Date: 1122289900

I am a real newbie with this BGP and AS stuff. If anyone wants to comment (Trevor, Nate, etc.) I appreciate it.