[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]

Inappropriate example in /wiki/Docs/Beats/Networking



Hi all, I have a question about the example of "Configurable
Source Address for ICMP Errors" in
http://fedoraproject.org/wiki/Docs/Beats/Networking

<quote>
For example, the kernel receives an ICMP echo request on the interface eth0. Because the new sysctl option is enabled, this causes the ICMP echo reply to be sent out via eth1. The address of eth0 is used when the default behavior would use the address of eth1.
</quote>

First of all, this new sysctl key refers ICMP *Error* messge.
It differs from ICMP Echo Reply. So, we are supposed to think
about the case that something error happens.

There is another point to be discussed. IMHO, former kernel
also uses eth1 interface to sent out the reply (as an error)
message in this case. The changed point caused by this new
feature is just IP address used in the reply packet. Kernel
routing shceme is unchanged in these new kernel releases.

My suggestion is:
  For example, the kernel receives a packet on the interface
  eth0 which cause ICMP Error and replies the ICMP Error
  messages via eth1 interface because of its routing table.
  If the the new sysctl option is enabled, the address of eth0
  is used for the source address of the ICMP Error while the
  default behavior would use the address of eth1.

-- 
SEKINE Tatsuo:
 tsekine sdri co jp    System Design & Research Inst. Co.,Ltd.
 http://www.amazon.co.jp/exec/obidos/ASIN/4797329750


[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]