Does a Linux machine know that a Router Advertisement didn't come from a default router?
I tried to send 2 RA packets using Scapy with the destination as ff02::1. One packet I sent using the source address of the default router, while the other using a lower LLA. The default routes were not generated. How did Linux figure it out? Is there a way to know the errors that were hit? I don't know where the "ND_PRINTK" outputs go for the function "ndisc_router_discovery". How do I enable tracing for ND prints. I looked into "dmesg" but there were no logs there. Dheeraj On Wed, Jun 15, 2022 at 12:27 PM Dheeraj Kandula <dkand...@gmail.com> wrote: > Thanks Marc. This is a requirement. > > Thus I will conclude that the kernel doesn't limit the number of RAs. I > have to figure out a way to do this from user space. > > Dheeraj > > On Wed, Jun 15, 2022 at 11:49 AM Marc Haber <mh+debian-i...@zugschlus.de> > wrote: > >> On Wed, Jun 15, 2022 at 10:23:18AM -0400, Dheeraj Kandula wrote: >> > This is to avoid DOS attacks using RAs from being bombarded onto a linux >> > machine. >> >> You have malicious users on your LAN and cannot do anything against >> them? >> >> (RAs are link local communication and should not pass over routers, >> thus, RAs must originate in the local network). >> >> Greetings >> Marc >> >> -- >> >> ----------------------------------------------------------------------------- >> Marc Haber | "I don't trust Computers. They | Mailadresse im >> Header >> Leimen, Germany | lose things." Winona Ryder | Fon: *49 6224 >> 1600402 >> Nordisch by Nature | How to make an American Quilt | Fax: *49 6224 >> 1600421 >> >>
