[HELP] How to change boot mode to SdxR5?

R

Ricky

Hi guys,

I heard something about a boot mode called SdxR5. It makes the SO faster and requires less RAM. I searched everywhere on the web but didn't find anything, so I was wondering if someone here ever heard about this "SdxR5" and could give me a hand :)

Thank you.
 
Where did you hear about this? There's zero information about it as far as I can see. It's a random string at best..
 
Probably the same thing as sending the new guy out to get landscape paper.
 
Well, I'm not 100% sure if the name of it is what I think it is. I will try to get more information from the place i heard it.

Anyway, you know something about a boot mode that make the SO faster?

Thanks for the answers.
 
I am sorry about the double post but I find that the denominated boot mode doesn't exist! It is basically: remove unused staff from the rc.conf

Mystery solved :)

Now, I would like to ask for some help to edit it. I'm new to FreeBSD, although I already acquired the basic Linux consents.
 
Problem solved, sorry for disturbing you.

Here is my rc.conf:

Code: 
ifconfig_em0="inet 192.168.5.100 netmask 255.0.0.0"
defaultrouter="192.168.5.1"
hostname="SOMETHING"
sshd_enable="yes"
mysql_enable="YES"
firewall_enable="YES"
firewall_type="/etc/rc.firewallt.rules"
firewall_quiet="YES"# -- sysinstall generated deltas -- # Sun May 29 00:56:13 2011
keymap="pt.iso"
 
Ricky said:
Here is my rc.conf:

Code: 
ifconfig_em0="inet 192.168.5.100 netmask 255.0.0.0"
Click to expand...
This can't be correct. RFC-1918 says this range is only a /16 and most people use it as a /24.
 
You have /8 netmask. Thus, valid private network would be 10.0.0.0. The "largest" netmask that you can have with 192.168 networks is 255.255.0.0.

With that kind of setup, non-private IP addresses can be seen as a part of your private LAN. http://www.bbn.com resolves to 192.1.122.17. Both that IP and 192.168.0.1 belong to same network under 255.0.0.0 netmask. That's what SirDice is talking about.
 
If the IP address is directly attached to Internet, you can't access anything since it's a private IP address.
If you are behind a NAT then it's fine. Mask is irrelevant, it's not carried in IP packet. I'm not sure what you are implying.
 
@bbzz

I don't think you fully grasp the issue.

He has given his computer a 192.168.5.100/8 IP address.

This means that as far as his computer is aware, anything that resolves to a 192.x.x.x IP address is on his local LAN. However, only addresses that start 192.168.x.x are actually private. There are numerous public services on the Internet that use IP's starting with 192, including http://www.bbn.com as mentioned.

Assuming he's behind NAT he will not be able to get to http://www.bbn.com as his computer will assume that the destination address is on his own LAN, rather than forwarding the packet to his gateway like it should. He's basically made any service on the Internet using a routable 192.x.x.x address unavailable to his computer.

He should be using a /16 or smaller netmask. And yes, mask is always relevant - it defines how your computer knows if another IP address is local (directly-connected) or not.
 
I see what you mean. But whether or not you'll connect depends on your connection, assuming you are behind NAT. Simple access to DNS, then APRing for "local" IP adress on ethernet will surely fail.
But that's not what I meant; My point was that you can configure IP ranges with any mask you want. There's no concept of A, B, C ranges. Thus it's perfectly fine to use original class C address with class A mask as long as you know what you are doing.
 
bbzz said:
then APRing for "local" IP adress on ethernet will surely fail.
Click to expand...

Yes it will fail, that's our point - we are making it clear that the system is configured in such a way that he may have problems accessing many Internet services. He probably wasn't aware of this and should change the IP settings.

Yes, there's no hard rule with netmasks. You can use a /24 with a 10.x.x.x IP and a /16 with a 192.x.x.x IP if you want, but when configuring a machine with private addresses that you want to connect to the Internet through NAT, you should make sure that it never overlaps real, public addresses.

You should always use
10.0.0.0 with /8 or higher
172.16.0.0 with /12 or higher
192.168.0.0 with /16 or higher

Using anything else is INCORRECT and shouldn't be done by anyone other than maybe for specific testing by someone who has a knowledgeable reason for configuring their system incorrectly.
 
Right; Like I said that's not what I was getting at, but the fact that RFC-1918 is not a requirement, but a recommendation. Reread my first reply.
 
Yes, I'm aware you can use any mask you want. I'm also aware you can also use any IP address you want.

My point was that his current configuration might work fine for most of the IP addresses but he will not be able to connect to any machine in the 192/8 range that isn't on his local subnet.

NAT (or private IP ranges for that matter) has nothing to do with this. It's a simple routing issue and a rookie networking mistake.
 
SirDice said:
NAT (or private IP ranges for that matter) has nothing to do with this. It's a simple routing issue and a rookie networking mistake.
Click to expand...

Technically speaking, it can make a difference. While private IP address will simply be filtered inbound by ISP or simply unroutable back, the scenario at hand can be solved if the aforementioned private IP is behind a NAT, with a technicality or two. Now whether one will know these is another issue.

But let's not go into that, the problem is solved.
 
192.0.0.0-192.167.255.255 and 192.169.0.0-192.255.255.255 are all very public, non-private, non-RFC1918, IP addresses, all 16,711,680 of them. Having 192.0.0.0-192.255.255.255 on your LAN because of a 255.0.0.0 netmask will force all traffic to them back to the LAN, not through NAT to the Internet. I'll write that on a wall so SirDice can bang his head against it some more ;)
 
DutchDaemon said:
192.0.0.0-192.167.255.255 and 192.169.0.0-192.255.255.255 are all very public, non-private, non-RFC1918, IP addresses, all 16,711,680 of them. Having 192.0.0.0-192.255.255.255 on your LAN because of a 255.0.0.0 netmask will force all traffic to them back to the LAN, not through NAT to the Internet. I'll write that on a wall so SirDice can bang his head against it some more ;)
Click to expand...

Right, right; That's not necessarily true is all I'm saying (the routing part).
Just like you can make it work if you use public range for numbering your internal LAN.
 
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