Re: DoS for web by failing reverse DNS?

[shadow () DEMENTIA ORG (Derrick J Brashear)]

On Fri, 16 Jun 2000, Meelis Roos wrote:

> > A few weeks ago I set up a VPN tunnel and tunneled 16 IP addresses onto a
> > LAN. At the time none of these addresses reverse-resolved to anything.
> >
> > I noticed upon connecting to some web servers that a connection was opened
> > and then hung forever, while others were fine. Some experimentation showed
>
> You may be hit by a Path MTU discovery problem because VPN usually
> decreases maximal available MTU: http://www.worldgate.com/~marcs/mtu/

Further exploration reveals that this is apparently the problem.
Interestingly there were a small number of web servers which were
initially unaccessible which became accessible shortly after the IP
addresses began reverse-resolving to something, but this may also be a
result of a path mtu change; As I can prove nothing in that vein at this
point, I'm content to assume I'm suffering only from the known issue above
rather than that I stumbled upon a new problem.

Thanks for your pointers, all of you.

-D