FWIW, the FreeBSD FAQ (10.9) sez this (it's a one-liner that shows the netmask 0xffffffff).
Regards, Justin On Wednesday, November 28, 2001, at 05:08 , Crist J. Clark wrote: > On Wed, Nov 28, 2001 at 08:37:42AM -0800, [EMAIL PROTECTED] wrote: >> >> somebody told me that, when aliasing, the 2nd to īnī ipaddress netmask >> must not be the regular one, but 0xffffffff instead. Example: >> >> rl0 = 200.200.200.200 netmask 255.255.0.0 >> rl0:0 (the aliased) 200.200.220.200 netmask 0xffffffff >> [lots more] >> rl0:3000 200.200.255.200 netmask 0xffffffff >> >> is it for real?? what is the reason for this? > > Somebody told you wrong. When adding an alias _which is on the same > logical network_ as other addresses, it should have an 0xffffffff > mask. That is, only one address on an interface should have the "real" > netmask for any one network. > > The simple explanation for this is that if you have, > > a.b.c.d/24 > a.b.c.e/24 > > On an interface and you try to initiate a connection to another > machine through this interface, should your connection use a.b.c.d or > a.b.c.e as the source address? It is ambiguous and can make problems. > > In your case, the addresses lie on different networks. Each address > should have the netmask of the network it is on. Note that you do not > have the above problem in this case. > -- > Crist J. Clark | [EMAIL PROTECTED] > | [EMAIL PROTECTED] > http://people.freebsd.org/~cjc/ | [EMAIL PROTECTED] > > To Unsubscribe: send mail to [EMAIL PROTECTED] > with "unsubscribe freebsd-net" in the body of the message > > -- /~\ The ASCII Justin C. Walker, Curmudgeon-at-large \ / Ribbon Campaign X Against HTML / \ Email! To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-net" in the body of the message
