internet attacks, Linux and non-Linux

[paolo furieri]

Often, in Internet places, there are perhaps 1 or many Linux server (I have 1),
perhaps 1 or many Non-Linux servers(I have 1 AIX RISC-6000),
and some routers (I have 2 CISCO 2511).
I have seeed that there are some new attack methods for crashing internet server
(syn, teardrop etc.). They somewhat attack Linux servers with old kernels.
If I update with new kernels and performs appropriate actions
(described is various documentations), propably I have a good protection
against such attacks.
Q. And for Non-Linux servers ? They have same problems ?
   (If YES, everyone must update his kernel).
   (If NO, they are better than Linux ? orror!!)
Q. And for routers ? They have same problems ?
   (If YES, how can anyone update them ? ).