Jonathan Brewer wrote:
Hi Folks,
I am wondering about the etiquette of reporting RFC1918 addresses back to hosts performing a traceroute. Example below:
Oooh goody, one of my favourite pet rants. :) RFC1918 addresses on routers is bad because if the router has to generate an ICMP error message it is sent with an RFC1918 source address (as your traceroute shows). These packets are often filtered by various devices using loose or strict reverse path filtering causing; * Traceroutes to have "*"'s in the middle of them. * pMTU discovery to break (ICMP Fragmentation required packets never make it back to the source) Other issues arise such as people trying to ssh to one machine inside their local network due to routing glitches ending up sshing into someone elses router. This also shows that ISP's in NZ aren't dropping packets sourced from bogus addresses at their boundary :) obrantlink: http://coders.meta.net.nz/wordpress/archives/2005/01/27/the-evils-of-rfc1918...
Hostname 1. ourhost.ourprovider.net.nz 2. f3-0-2.core1.wlg.ourprovider.net.nz 3. f0-0-4.core3.wlg.ourprovider.net.nz 4. f4-0-5.core2.akl.ourprovider.net.nz 5. g1-0-1396.u12.brfd.otherprovider.net.nz 6. g1-0-1043.u12.brh.otherprovider.net.nz 7. 10.65.32.1 8. 10.65.32.250 9. 10.69.0.2 10. a12-3-23.u21.tar.otherprovider.net.nz 11. fa7-4-1042.bigrouter.otherprovider.net.nz 12. otherhost.otherprovider.net.nz
Any comments on this practice?