f



IP 0.0.0.0/0 - 0.0.0.0/32

Hi

Any useful link that explains this IP address range in details, please?

Thanks in advance!

The Dude 


0
The
8/24/2006 12:29:29 AM
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In article <Jp6Hg.458762$IK3.24918@pd7tw1no>,
The Dude <The Dude@thedu.de> wrote:

>Any useful link that explains this IP address range in details, please?

Urrr -- 0.0.0.0/0 is the *entire* IPv4 address range, and
0.0.0.0/32 is just the single IPv4 address 0.0.0.0.

For any given network, the lowest address in the network is
reserved. Historically, the lowest address was one of the two
allowed choices for the broadcast address; later, the broadcast
address was standardized as being the highest address in the
network only.

You should only see traffic coming from the lowest address in
a network if the link is a point-to-point link and the network is
either a /31 or a /32.

One exception to that is that when a system is DHCP'ing,
it does not yet know its IP address, and so it is allowed to
use the IP address 0.0.0.0 as its source IP.
0
roberson
8/24/2006 1:49:56 AM
"Walter Roberson" <roberson@hushmail.com> wrote in message 
news:8B7Hg.459285$IK3.362963@pd7tw1no...
> In article <Jp6Hg.458762$IK3.24918@pd7tw1no>,
> The Dude <The Dude@thedu.de> wrote:
>
>>Any useful link that explains this IP address range in details, please?
>
> Urrr -- 0.0.0.0/0 is the *entire* IPv4 address range, and
> 0.0.0.0/32 is just the single IPv4 address 0.0.0.0.
>

As you know, subnet masks use 1s to match the bits and 0 to ignore the bits; 
1s indicate the network portion and 0s indicate the host portion of the IP 
address. Now, IP address 0.0.0.0/0 is considered the default ip route, 
whereas IP address 0.0.0.0/32 means _ any network_ with _any mask. I wish I 
could found some study material on this particular subject ...

The Dude 


0
The
8/24/2006 3:08:53 AM
In article <9L8Hg.448204$iF6.409035@pd7tw2no>,
The Dude <The Dude@thedu.de> wrote:
>As you know, subnet masks use 1s to match the bits and 0 to ignore the bits; 
>1s indicate the network portion and 0s indicate the host portion of the IP 
>address.

True, but you didn't use any subnet masks in your question.
You used CIDR notation, not masks.

>Now, IP address 0.0.0.0/0 is considered the default ip route, 

Yes.

>whereas IP address 0.0.0.0/32 means _ any network_ with _any mask.

I've never seen 0.0.0.0/32 used for -anything-, but I see in
RFC 3330 that

   0.0.0.0/8 - Addresses in this block refer to source hosts on "this"
   network.  Address 0.0.0.0/32 may be used as a source address for this
   host on this network; other addresses within 0.0.0.0/8 may be used to
   refer to specified hosts on this network [RFC1700, page 4].

Definitely not "any network with any mask".

0.0.0.0/32 is 0.0.0.0 with a netmask which has 32 leading 1's. By
your explanation, the leading 1's are the network portion. There isn't
any room left for a host mask, so 0.0.0.0/32 cannot be
"any network with any mask": it means one very specific network with
one very specific mask.


>I wish I 
>could found some study material on this particular subject ...

I'm not sure what kind of material you are looking for? RFC 3330 is
"Special-Use IPv4 Addresses".
0
roberson
8/24/2006 4:09:06 AM
"Walter Roberson" <roberson@hushmail.com> wrote in message 
news:CD9Hg.448475$iF6.189742@pd7tw2no...
> In article <9L8Hg.448204$iF6.409035@pd7tw2no>,
> The Dude <The Dude@thedu.de> wrote:
>>As you know, subnet masks use 1s to match the bits and 0 to ignore the 
>>bits;
>>1s indicate the network portion and 0s indicate the host portion of the IP
>>address.
>
> True, but you didn't use any subnet masks in your question.
> You used CIDR notation, not masks.


isn't  0.0.0.0/0 the same as 0.0.0.0 0.0.0.0  and 0.0.0.0/32  the same as 
0.0.0.0 255.255.255.255 ?


>
>>Now, IP address 0.0.0.0/0 is considered the default ip route,
>
> Yes.
>
>>whereas IP address 0.0.0.0/32 means _ any network_ with _any mask.
>
> I've never seen 0.0.0.0/32 used for -anything-,



0.0.0.0 255.255.255.255 is used for IP routing .



but I see in
> RFC 3330 that
>
>   0.0.0.0/8 - Addresses in this block refer to source hosts on "this"
>   network.  Address 0.0.0.0/32 may be used as a source address for this
>   host on this network; other addresses within 0.0.0.0/8 may be used to
>   refer to specified hosts on this network [RFC1700, page 4].



I have seen that and it does not tell me much.



>
> Definitely not "any network with any mask".
>
> 0.0.0.0/32 is 0.0.0.0 with a netmask which has 32 leading 1's. By
> your explanation, the leading 1's are the network portion. There isn't
> any room left for a host mask, so 0.0.0.0/32 cannot be
> "any network with any mask": it means one very specific network with
> one very specific mask.

The Dude 


0
The
8/24/2006 4:42:38 AM
The Dude wrote:

> isn't  0.0.0.0/0 the same as 0.0.0.0 0.0.0.0  and 0.0.0.0/32  the same as
> 0.0.0.0 255.255.255.255 ?

Yes. So it doesn't mean "any network with any mask". It means the exact
IP address 0.0.0.0. Since the subnet mask is all 1's, all the bits are
matched. So the only IP address that matches is 0.0.0.0. 0.0.0.1
doesn't match because the last bit differs and the last bit must match
because there's a '1' in that bit position in the mask.

Similarly, 0.0.0.0/8 is the same as 0.0.0.0 with a mask of 255.0.0.0.
This means the first octet must match but the last three need not. So
this network includes 0.1.0.9 but not 1.0.0.0.

DS

0
David
8/24/2006 4:52:41 AM
roberson@hushmail.com (Walter Roberson) writes:
> >whereas IP address 0.0.0.0/32 means _ any network_ with _any mask.
> 
> I've never seen 0.0.0.0/32 used for -anything-, but I see in

It's INADDR_ANY -- it usually means "no such host."

> RFC 3330 that
> 
>    0.0.0.0/8 - Addresses in this block refer to source hosts on "this"
>    network.  Address 0.0.0.0/32 may be used as a source address for this
>    host on this network; other addresses within 0.0.0.0/8 may be used to
>    refer to specified hosts on this network [RFC1700, page 4].

Another common use for 0.0.0.0/8 is to designate ifIndex numbers, as
for the "Link Data" value in OSPF, and for some BSD-ish interfaces.

-- 
James Carlson, KISS Network                    <james.d.carlson@sun.com>
Sun Microsystems / 1 Network Drive         71.232W   Vox +1 781 442 2084
MS UBUR02-212 / Burlington MA 01803-2757   42.496N   Fax +1 781 442 1677
0
James
8/24/2006 11:50:41 AM
The Dude wrote:
[snip: ip addressing]
.. I wish I could found some study material on
> this particular subject ...

google for it.
http://www.networkclue.com/routing/tcpip/addressing.aspx comes up as
does many other sites.



-- 

hsb


"Somehow I imagined this experience would be more rewarding" Calvin
**************************ROT13 MY ADDRESS*************************
Due to the volume of email that I receive, I may not be able to
reply to emails sent to my account. Please post a followup instead.
********************************************************************
0
Hansang
8/25/2006 3:12:51 AM
"Hansang Bae" <uonr@alp.ee.pbz> wrote in message 
news:TUtHg.46178$u05.39618@news-wrt-01.rdc-nyc.rr.com...
> The Dude wrote:
> [snip: ip addressing]
> . I wish I could found some study material on
>> this particular subject ...
>
> google for it.
> http://www.networkclue.com/routing/tcpip/addressing.aspx comes up as
> does many other sites.

This link does not deal with my subject, but thanks anyway....
FYI, before I ask here, I search engines, google included, but I am not 
always lucky ...

Regarding my statement 0.0.0.0 (any network) 255.255.255.255 (any mask), I 
was refering to ACL wildcard ... My bad.
ACL and OSPF use wildcards which are opposite of normal subnet masks (I 
wonder why) ....

Thanks for the feedback.

The Dude 


0
The
8/25/2006 3:47:39 AM
The Dude wrote:

> Regarding my statement 0.0.0.0 (any network) 255.255.255.255 (any mask), I
> was refering to ACL wildcard ... My bad.
> ACL and OSPF use wildcards which are opposite of normal subnet masks (I
> wonder why) ....

I think the theory is that wildcards are more flexible. For example,
suppose you want to block all addresses of the form 216.152.*.255. You
can do that with wildcards but not with subnet masks.

It may also just be a closer match with how they "think" internally.

DS

0
David
8/25/2006 4:30:29 AM
In article <1156480229.830288.152470@i42g2000cwa.googlegroups.com>,
David Schwartz <davids@webmaster.com> wrote:

>The Dude wrote:

>> Regarding my statement 0.0.0.0 (any network) 255.255.255.255 (any mask), I
>> was refering to ACL wildcard ... My bad.
>> ACL and OSPF use wildcards which are opposite of normal subnet masks (I
>> wonder why) ....

>I think the theory is that wildcards are more flexible. For example,
>suppose you want to block all addresses of the form 216.152.*.255. You
>can do that with wildcards but not with subnet masks.

Yes you can. You can't do it with CIDR notation, but subnet masks
are not required to use consequative bits.


>It may also just be a closer match with how they "think" internally.

Not even necessarily that. Reversing the mask logic for access lists
may have originally simply been intended to prevent confusion.
Subnet masks carry with them the implication that the first and
last addresses in the induced range are reserved for broadcast
traffic, so to avoid having people ask about that over and over again,
they may have chosen to use a distinctly different convention that
did not have that baggage.
0
roberson
8/25/2006 2:22:37 PM
In article <vpuHg.464648$IK3.282381@pd7tw1no>,
The Dude <The Dude@thedu.de> wrote:

>Regarding my statement 0.0.0.0 (any network) 255.255.255.255 (any mask), I 
>was refering to ACL wildcard ... My bad.
>ACL and OSPF use wildcards which are opposite of normal subnet masks (I 
>wonder why) ....

I haven't looked at OSPF in a long time, so I cannot comment on that.

ACL, "access control lists", are done differently by different
manufacturers and different software products. 0.0.0.0 255.255.255.255
as meaning "all IP addresses", is typical in Cisco IOS "extended"
access lists. There is no standard about that, it's just what
Cisco IOS uses. Cisco's PIX and ASA security appliances use the same
bit convention as for subnet masks.
0
roberson
8/25/2006 2:26:09 PM
The Dude wrote:
> This link does not deal with my subject, but thanks anyway....
> FYI, before I ask here, I search engines, google included, but I am
> not always lucky ...
> 
> Regarding my statement 0.0.0.0 (any network) 255.255.255.255 (any
> mask), I was refering to ACL wildcard ... My bad.  ACL and OSPF use
> wildcards which are opposite of normal subnet masks (I wonder why)


Wildcards are easy to master if (and only if) you convert the IPs to
binary numbers.  If you understand the logic of binary AND and binary
OR operations, it will become crystal clear.  Breaking it down to
binary numbers is the only way to calculate complicated acls.  But this
topic is better suited for comp.dcom.sys.cisco.

-- 

hsb


"Somehow I imagined this experience would be more rewarding" Calvin
**************************ROT13 MY ADDRESS*************************
Due to the volume of email that I receive, I may not be able to
reply to emails sent to my account. Please post a followup instead.
********************************************************************
0
Hansang
8/26/2006 2:35:10 AM
"Hansang Bae" <uonr@alp.ee.pbz> wrote in message 
news:yrOHg.24771$v82.5419@news-wrt-01.rdc-nyc.rr.com...
> The Dude wrote:
>> This link does not deal with my subject, but thanks anyway....
>> FYI, before I ask here, I search engines, google included, but I am
>> not always lucky ...
>>
>> Regarding my statement 0.0.0.0 (any network) 255.255.255.255 (any
>> mask), I was refering to ACL wildcard ... My bad.  ACL and OSPF use
>> wildcards which are opposite of normal subnet masks (I wonder why)
>
>
> Wildcards are easy to master if (and only if) you convert the IPs to
> binary numbers.  If you understand the logic of binary AND and binary
> OR operations, it will become crystal clear.  Breaking it down to
> binary numbers is the only way to calculate complicated acls.  But this
> topic is better suited for comp.dcom.sys.cisco.
>
I do not know about the details, but I find it easy by reversing the normal 
subnet mask, i.e.:
the wild card for A.B.C.D/ 27  (255.255.255.224) is 0.0.0.31 (255-224)

The Dude


0
The
8/26/2006 4:21:49 PM
On Sat, 26 Aug 2006, in the Usenet newsgroup comp.protocols.tcp-ip, in article
<xy_Hg.476263$IK3.433011@pd7tw1no>, The Dude wrote:

>"Hansang Bae" <uonr@alp.ee.pbz> wrote

>> Wildcards are easy to master if (and only if) you convert the IPs to
>> binary numbers.  If you understand the logic of binary AND and binary
>> OR operations, it will become crystal clear.

Agreed - once you understand the binary, hex or CIDR is a piece of cake.

>I do not know about the details, but I find it easy by reversing the normal
>subnet mask, i.e.:
>the wild card for A.B.C.D/ 27  (255.255.255.224) is 0.0.0.31 (255-224)

1518 An Architecture for IP Address Allocation with CIDR. Y. Rekhter,
     T. Li. September 1993. (Format: TXT=72609 bytes) (Status: PROPOSED
     STANDARD)

1519 Classless Inter-Domain Routing (CIDR): an Address Assignment and
     Aggregation Strategy. V. Fuller, T. Li, J. Yu, K. Varadhan. September
     1993. (Format: TXT=59998 bytes) (Obsoletes RFC1338) (Status: PROPOSED
     STANDARD)

1878 Variable Length Subnet Table For IPv4. T. Pummill, B. Manning.
     December 1995. (Format: TXT=19414 bytes) (Obsoletes RFC1860) (Status:
     INFORMATIONAL)

RFCs are available on very many web sites - three examples being

   http://www.ietf.org/rfc/rfc0000.txt
   http://www.faqs.org/rfcs/rfc0000.html
   http://www.rfc-editor.org/rfc/rfc0000.txt

replace the four zeros with the four digit RFC number.

        Old guy
0
ibuprofin
8/27/2006 9:05:51 PM
The Dude wrote:
[Cisco wildcards for ACLs]
> I do not know about the details, but I find it easy by reversing the
> normal subnet mask, i.e.:  the wild card for A.B.C.D/ 27
> (255.255.255.224) is 0.0.0.31 (255-224)

And what will you do if someone asks you to create an ACL that will
block every fourth host on a /26 network?  i.e. x.x.x.4, x.x.x.68,
x.x.x.132, x.x.x.196 but permit others?

Of course you can use four denies at the top and permit the block, but
for education sake, what if I told you that you can do this with one
line?

permit ip x.x.x.4 255.255.255.192 is the line you're looking for.

You really can't do this in your head w/o breaking it down into binary
numbers.

Before someone jumps in, yes, sometimes engineering elegance can lead
to operational confusion.  But this example is just that, an example.

-- 

hsb


"Somehow I imagined this experience would be more rewarding" Calvin
**************************ROT13 MY ADDRESS*************************
Due to the volume of email that I receive, I may not be able to
reply to emails sent to my account. Please post a followup instead.
********************************************************************
0
Hansang
8/29/2006 2:06:58 AM
"Hansang Bae" <uonr@alp.ee.pbz> wrote in message 
news:6jNIg.47239$u05.11356@news-wrt-01.rdc-nyc.rr.com...
> The Dude wrote:
> [Cisco wildcards for ACLs]
>> I do not know about the details, but I find it easy by reversing the
>> normal subnet mask, i.e.:  the wild card for A.B.C.D/ 27
>> (255.255.255.224) is 0.0.0.31 (255-224)
>
> And what will you do if someone asks you to create an ACL that will
> block every fourth host on a /26 network?  i.e. x.x.x.4, x.x.x.68,
> x.x.x.132, x.x.x.196 but permit others?

>
> Of course you can use four denies at the top and permit the block, but
> for education sake, what if I told you that you can do this with one
> line?
>
> permit ip x.x.x.4 255.255.255.192 is the line you're looking for.


The wild card should be 0.0.0.63.


>
> You really can't do this in your head w/o breaking it down into binary
> numbers.


I have imagination the same way a chess player can play the entire game 
blindfold.

The Dude 


0
The
8/29/2006 5:26:11 AM
"The Dude" <The Dude@thedu.de> wrote in message 
news:TdQIg.492503$IK3.360274@pd7tw1no...
>
> "Hansang Bae" <uonr@alp.ee.pbz> wrote in message 
> news:6jNIg.47239$u05.11356@news-wrt-01.rdc-nyc.rr.com...
>> The Dude wrote:
>> [Cisco wildcards for ACLs]
>>> I do not know about the details, but I find it easy by reversing the
>>> normal subnet mask, i.e.:  the wild card for A.B.C.D/ 27
>>> (255.255.255.224) is 0.0.0.31 (255-224)
>>
>> And what will you do if someone asks you to create an ACL that will
>> block every fourth host on a /26 network?  i.e. x.x.x.4, x.x.x.68,
>> x.x.x.132, x.x.x.196 but permit others?

First of all, there are only 3 subnetworks on a /26 network , not 4!

x.x.x.0, x.x.x.64, and x.x.x.128


>>
>> Of course you can use four denies at the top and permit the block, but
>> for education sake, what if I told you that you can do this with one
>> line?
>>
>> permit ip x.x.x.4 255.255.255.192 is the line you're looking for.

I do not see how your line can block every 4 th host and how your line can 
be any different than

"permit ip x.x.x.4 0.0.0.63". Note: ACL uses wildcards.

The Dude 


0
The
8/29/2006 2:02:54 PM
In article <iOXIg.480998$Mn5.225834@pd7tw3no>, "The Dude" <The Dude@thedu.de> writes:
> 
> "The Dude" <The Dude@thedu.de> wrote in message 
> news:TdQIg.492503$IK3.360274@pd7tw1no...
>>
>> "Hansang Bae" <uonr@alp.ee.pbz> wrote in message 
>> news:6jNIg.47239$u05.11356@news-wrt-01.rdc-nyc.rr.com...
>>> The Dude wrote:
>>> [Cisco wildcards for ACLs]
>>>> I do not know about the details, but I find it easy by reversing the
>>>> normal subnet mask, i.e.:  the wild card for A.B.C.D/ 27
>>>> (255.255.255.224) is 0.0.0.31 (255-224)
>>>
>>> And what will you do if someone asks you to create an ACL that will
>>> block every fourth host on a /26 network?  i.e. x.x.x.4, x.x.x.68,
>>> x.x.x.132, x.x.x.196 but permit others?
> 
> First of all, there are only 3 subnetworks on a /26 network , not 4!
> 
> x.x.x.0, x.x.x.64, and x.x.x.128

Don't know what you're talking about or what the relevance is.

There are four possible values for the final octet in the "host 4"
IP address of a /26 network.  Those are x.x.x.4, x.x.x.68,
x.x.x.132 and x.x.x.196

It is the blocking of the "host 4" IP address in all possible /26 netblocks
that we're after.  There isn't any subnetting going on.

[It took me a bit to catch on.  "Every 4th host" isn't very good wording.
Initially it sounded to me like he wanted the low order two bits of all
the blocked IP addresses to be identical.]

>>> Of course you can use four denies at the top and permit the block, but
>>> for education sake, what if I told you that you can do this with one
>>> line?
>>>
>>> permit ip x.x.x.4 255.255.255.192 is the line you're looking for.
> 
> I do not see how your line can block every 4 th host and how your line can 
> be any different than
> 
> "permit ip x.x.x.4 0.0.0.63". Note: ACL uses wildcards.

Why are you specifying a 4 and then wildcarding it with a 63?

RTR(config-ext-nacl)#deny ip 1.2.3.4 0.0.0.63 any
RTR(config-ext-nacl)#^Z
RTR#show ip access-list test
Extended IP access list test
    deny ip 1.2.3.0 0.0.0.63 any

IOS properly ignored the "4".

How does this succeed in blocking every 4th host?


Of course we may also ask:

"Why is he specifying x.x.x and then wildcarding it with a 255.255.255.192?"

RTR(config)#ip access-list extended test
RTR(config-ext-nacl)#deny ip 1.2.3.4 255.255.255.192 any
RTR(config-ext-nacl)#^Z
RTR#show ip access-list test
Extended IP access list test
    deny ip 0.0.0.4 255.255.255.192 any

This ACL entry nicely handles the stated problem.

I'm using the IOS convention that wildcard masks use set bits to indicate
wildcard positions and clear bits to indicate positions that must match
the specified IP address.  The PIX convention is, of course, the reverse.
0
briggs
8/29/2006 4:40:00 PM
<briggs@encompasserve.org> wrote in message 
news:G5enUT4+Exyi@eisner.encompasserve.org...
> In article <iOXIg.480998$Mn5.225834@pd7tw3no>, "The Dude" <The 
> Dude@thedu.de> writes:
>>
>> "The Dude" <The Dude@thedu.de> wrote in message
>> news:TdQIg.492503$IK3.360274@pd7tw1no...
>>>
>>> "Hansang Bae" <uonr@alp.ee.pbz> wrote in message
>>> news:6jNIg.47239$u05.11356@news-wrt-01.rdc-nyc.rr.com...
>>>> The Dude wrote:
>>>> [Cisco wildcards for ACLs]
>>>>> I do not know about the details, but I find it easy by reversing the
>>>>> normal subnet mask, i.e.:  the wild card for A.B.C.D/ 27
>>>>> (255.255.255.224) is 0.0.0.31 (255-224)
>>>>
>>>> And what will you do if someone asks you to create an ACL that will
>>>> block every fourth host on a /26 network?  i.e. x.x.x.4, x.x.x.68,
>>>> x.x.x.132, x.x.x.196 but permit others?
>>
>> First of all, there are only 3 subnetworks on a /26 network , not 4!
>>
>> x.x.x.0, x.x.x.64, and x.x.x.128
>
> Don't know what you're talking about or what the relevance is.
>
> There are four possible values for the final octet in the "host 4"
> IP address of a /26 network.  Those are x.x.x.4, x.x.x.68,
> x.x.x.132 and x.x.x.196
>
> It is the blocking of the "host 4" IP address in all possible /26 
> netblocks
> that we're after.  There isn't any subnetting going on.
>
> [It took me a bit to catch on.  "Every 4th host" isn't very good wording.
> Initially it sounded to me like he wanted the low order two bits of all
> the blocked IP addresses to be identical.]
>
>>>> Of course you can use four denies at the top and permit the block, but
>>>> for education sake, what if I told you that you can do this with one
>>>> line?
>>>>
>>>> permit ip x.x.x.4 255.255.255.192 is the line you're looking for.
>>
>> I do not see how your line can block every 4 th host and how your line 
>> can
>> be any different than
>>
>> "permit ip x.x.x.4 0.0.0.63". Note: ACL uses wildcards.
>
> Why are you specifying a 4 and then wildcarding it with a 63?
>
> RTR(config-ext-nacl)#deny ip 1.2.3.4 0.0.0.63 any
> RTR(config-ext-nacl)#^Z
> RTR#show ip access-list test
> Extended IP access list test
>    deny ip 1.2.3.0 0.0.0.63 any
>
> IOS properly ignored the "4".
>
> How does this succeed in blocking every 4th host?
>
>
> Of course we may also ask:
>
> "Why is he specifying x.x.x and then wildcarding it with a 
> 255.255.255.192?"
>
> RTR(config)#ip access-list extended test
> RTR(config-ext-nacl)#deny ip 1.2.3.4 255.255.255.192 any
> RTR(config-ext-nacl)#^Z
> RTR#show ip access-list test
> Extended IP access list test
>    deny ip 0.0.0.4 255.255.255.192 any
>
> This ACL entry nicely handles the stated problem.
>
> I'm using the IOS convention that wildcard masks use set bits to indicate
> wildcard positions and clear bits to indicate positions that must match
> the specified IP address.  The PIX convention is, of course, the reverse.

255.255.255.255 is called host mask and specifies the network of one host.
In the following example it's used to advertise a loopback network:

(config)# int loopback 0
(config-if)# ip address 192.168.31.33 255.255.255.255

The Dude


0
The
8/30/2006 1:52:37 AM
[snip: how to block every fourth (ordinal) host IP address of /26
networks]


> > > permit ip x.x.x.4 255.255.255.192 is the line you're looking for.


The Dude wrote:
[snip]
> I do not see how your line can block every 4 th host and how your
> line can be any different than

You can't see it because you don't understand binary.  It's just that
simple.  I hope you're a damn good chess player because you will not go
very far in the tech field with your current attitude.  You lack the
fundamental "gee, I wonder why that is....let me find out!"
requirement.  There are people you can learn from and there are people
you can safely ignore.  It's up to you to decide who fits the former
and who fits in the latter.

> 
> "permit ip x.x.x.4 0.0.0.63". Note: ACL uses wildcards.

As does my "permit ip x.x.x.4 255.255.255.192"  Again, you lack the
foundation.  It's time to hit the books again and try to understand the
concepts.


-- 

hsb


"Somehow I imagined this experience would be more rewarding" Calvin
**************************ROT13 MY ADDRESS*************************
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0
Hansang
8/30/2006 2:17:39 AM
The Dude wrote:
[Briggs and are, of course, talking about wildcard masking on Cisco
routers]

> 255.255.255.255 is called host mask and specifies the network of one
> host.  In the following example it's used to advertise a loopback
> network:
> 
> (config)# int loopback 0
> (config-if)# ip address 192.168.31.33 255.255.255.255

Dude,
Couple of Mark Twain's quotes are apropos here:

1)  It is wiser to find out than to suppose.
2)  It is best to keep your mouth shut and be presumed ignorant than to
open it and remove all doubt.  (or any variation of this quote)

If you want to make it in this field, you have to take #1 to heart.


-- 

hsb


"Somehow I imagined this experience would be more rewarding" Calvin
**************************ROT13 MY ADDRESS*************************
Due to the volume of email that I receive, I may not be able to
reply to emails sent to my account. Please post a followup instead.
********************************************************************
0
Hansang
8/30/2006 2:54:26 AM
"Hansang Bae" <uonr@alp.ee.pbz> wrote in message 
news:C57Jg.48301$u05.12189@news-wrt-01.rdc-nyc.rr.com...
> The Dude wrote:
> [Briggs and are, of course, talking about wildcard masking on Cisco
> routers]
>
>> 255.255.255.255 is called host mask and specifies the network of one
>> host.  In the following example it's used to advertise a loopback
>> network:
>>
>> (config)# int loopback 0
>> (config-if)# ip address 192.168.31.33 255.255.255.255
>
> Dude,
> Couple of Mark Twain's quotes are apropos here:
>
> 1)  It is wiser to find out than to suppose.
> 2)  It is best to keep your mouth shut and be presumed ignorant than to
> open it and remove all doubt.  (or any variation of this quote)
>
> If you want to make it in this field, you have to take #1 to heart.

You suppose first (based on your knowledge and experience) and you find out 
next.

The second one suggests that people are born ignorant and should die 
ignorant.

As for binary here is a way for you to learn how to memorize things:

128    192   224   240   248    252    254    255
128     64     32      16     8        4         2       1
 1         2        3        4      5       6         7        8

                               32
                               48
                      64     64
                               70
                      96     96
                             112
            128  128   128
                             144
                    160   160
                             176
                    192   192
                             208
                             224

If you do not understand any of the above, feel free to ask. That's what I 
am here for!

The Dude 


0
The
8/31/2006 12:55:11 AM
The Dude wrote:
[snip]
> As for binary here is a way for you to learn how to memorize things:
> 128    192   224   240   248    252    254    255
> 128     64     32      16     8        4         2       1
> 1         2        3        4      5       6         7        8

Herein lies the issue at heart.  You want to "memorize" something
because you simply do not understand binary math.  If you understand
binary math you would

a)  understand what the hell I'm talking about
b)  understand what masking is all about
c)  understand the subnet mask and wildcard masks are different - but
is not limited to 255.255.255.x and 0.0.0.x syntax for the former and
the latter
d)  understand how to derive complicated ACL wildcard masks.


> If you do not understand any of the above, feel free to ask. That's
> what I am here for!


Something tells me that will not happen, but hey, you never know.
Thanks for the offer.


-- 

hsb


"Somehow I imagined this experience would be more rewarding" Calvin
**************************ROT13 MY ADDRESS*************************
Due to the volume of email that I receive, I may not be able to
reply to emails sent to my account. Please post a followup instead.
********************************************************************
0
Hansang
8/31/2006 2:07:34 AM
Reply: