我正在尝试找到一种方法,用于枚举数据包在互联网上可能采取的一些可能路由,特别是计算它可能在路由上传递的AS。
这是否可行,我是否能够收集离线计算所需的所有信息(即所有BGP路由的可能一致的快照)?
答案 0 :(得分:1)
编写我认为你要问的那种算法可能并不像你希望的那么容易。
是否可以计算数据包的潜在 AS路径的答案是不合格的。您可以通过连接BGP Looking Glass获得大量的互联网图片。您可以连接到多个BGP Looking Glasses并从中提取整个BGP表。
由于以下原因,您是否能够以任何一致的概率计算数据包的未来路径是一项非常困难的工作:
来自routeviews.org的Cisco IOS BGP Looking Glass的示例输出:
bgp-views>show ip bgp 4.0.0.0
BGP routing table entry for 4.0.0.0/9, version 658263
Paths: (35 available, best #13, table Default-IP-Routing-Table)
Not advertised to any peer
19214 25973 3356, (aggregated by 3356 4.69.130.2)
208.74.64.40 from 208.74.64.40 (208.74.64.40)
Origin IGP, localpref 100, valid, external, atomic-aggregate
852 1299 3356, (aggregated by 3356 4.69.130.18)
154.11.98.225 from 154.11.98.225 (154.11.98.225)
Origin IGP, metric 0, localpref 100, valid, external, atomic-aggregate
Community: 852:180
852 1299 3356, (aggregated by 3356 4.69.130.10)
154.11.11.113 from 154.11.11.113 (154.11.11.113)
Origin IGP, metric 0, localpref 100, valid, external, atomic-aggregate
Community: 852:180
3561 3356, (aggregated by 3356 4.69.130.2)
206.24.210.102 from 206.24.210.102 (206.24.210.102)
Origin IGP, localpref 100, valid, external, atomic-aggregate
812 6461 3356, (aggregated by 3356 4.69.130.12)
64.71.255.61 from 64.71.255.61 (64.71.255.61)
Origin IGP, localpref 100, valid, external, atomic-aggregate
3277 3267 1273 1273 3356, (aggregated by 3356 4.69.130.76)
194.85.102.33 from 194.85.102.33 (194.85.4.4)
Origin IGP, localpref 100, valid, external, atomic-aggregate
Community: 3277:3267 3277:65321 3277:65323 3277:65330
6939 1299 3356, (aggregated by 3356 4.69.130.2)
216.218.252.164 from 216.218.252.164 (216.218.252.164)
Origin IGP, localpref 100, valid, external, atomic-aggregate
286 3356, (aggregated by 3356 4.69.130.82)
134.222.87.1 (inaccessible) from 134.222.87.1 (134.222.85.99)
Origin IGP, localpref 100, valid, external, atomic-aggregate
Community: 286:18 286:19 286:29 286:800 286:888 286:3031 286:4010
[table manually truncated for brevity]
bgp-views>
与BGP分析相关的一些相关链接......
这是来自bgplay的示例AS图表,您可能会感兴趣...这是从NASA的BGP自治系统(AS297)的BGP路径信息的时间重放截图。
修改强>
我是一名专业的网络工程师;编码是我为提高网络工程技能所做的工作。关于你对routeviews.org是否拥有良好数据的问题,当我与一个大型网络设备制造商的开发团队合作时,仍然无名,Routeviews.org是我的实时BGP表信息的实际来源。另外,我在调试互联网路由问题时总是使用Routeviews。他们的原始bgp Looking Glass数据与您免费获得的数据一样好。