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Can not access Certain sites

 
 
Jeremy McMasters
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      09-22-2004
I am curious to whether anyone on this board has ever ran into a problem
where if you have a .0 or a .255 as an ip address (last octet) that you
can't access websites like www.ebay.com or www.microsoft.com. I have a /21
that I have handling otu ip address's to subscribers using Cisco Network
Registrar. I am wondering if there is something I need to do on Layer 3 or
this needs to be escalated to my upstream-provider


 
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Rod Dorman
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      09-22-2004
In article <(E-Mail Removed)>,
Jeremy McMasters <(E-Mail Removed)> wrote:
> I am curious to whether anyone on this board has ever ran into a
>problem where if you have a .0 or a .255 as an ip address (last
>octet) that you can't access websites like www.ebay.com or
>www.microsoft.com. I have a /21 that I have handling otu ip
>address's to subscribers using Cisco Network Registrar. I am
>wondering if there is something I need to do on Layer 3 or this needs
>to be escalated to my upstream-provider


I've got a SMC7004VWBR at home that has an issue with .0 or .255 when
I enabled the more aggressive firewall features. It would start
complaining about "smurf" attacks even though it knew the netmask and
should have realized the IP address wasn't the broadcast address.

It didn't affect just a couple of websites though, it was unusable
until I disabled the anti-DOS option.

--
-- Rod --
rodd(at)polylogics(dot)com
 
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S. Gione
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      09-22-2004
..0 is reserved (network address)
..255 is reserved - broadcast.

"Jeremy McMasters" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> I am curious to whether anyone on this board has ever ran into a

problem
> where if you have a .0 or a .255 as an ip address (last octet) that you
> can't access websites like www.ebay.com or www.microsoft.com. I have a

/21
> that I have handling otu ip address's to subscribers using Cisco Network
> Registrar. I am wondering if there is something I need to do on Layer 3

or
> this needs to be escalated to my upstream-provider
>
>



 
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S. Gione
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      09-22-2004
Cancel my prior statement ... I did not initially notice the 21 bit network
notation.

Network would include zeros in the 3 low-order bits of the 3rd octet and
broadcast 1s in those bit positions.

This is assuming the network mask is set for 248 in the third octet.

"S. Gione" <(E-Mail Removed)> wrote in message
news:O6k4d.16769$(E-Mail Removed)...
> .0 is reserved (network address)
> .255 is reserved - broadcast.
>
> "Jeremy McMasters" <(E-Mail Removed)> wrote in message
> news:(E-Mail Removed)...
> > I am curious to whether anyone on this board has ever ran into a

> problem
> > where if you have a .0 or a .255 as an ip address (last octet) that you
> > can't access websites like www.ebay.com or www.microsoft.com. I have a

> /21
> > that I have handling otu ip address's to subscribers using Cisco Network
> > Registrar. I am wondering if there is something I need to do on Layer 3

> or
> > this needs to be escalated to my upstream-provider
> >
> >

>
>



 
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Walter Roberson
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      09-22-2004
In article <O6k4d.16769$(E-Mail Removed)>,
S. Gione <(E-Mail Removed)> wrote:
:.0 is reserved (network address)
:.255 is reserved - broadcast.

Incorrect. The all-zero "host" portion of an IP address is reserved,
and the all-ones "host" portion of an IP address is reserved, but
even in the old Class A/B/C/D days, that didn't automatically mean
that .0 and .255 were reserved.

For example, the class B address 132.133.0.0 is reserved and
132.133.255.255 would be reserved too for Class B, but (say)
132.133.18.255 would not be reserved. For Class B, the "network"
portion of the address is "132.133" and the host portion is the
remaining 16 bits, and the address is reserved only if all 16 of those
remaining bits are pure 0's or pure 1's.

Of course, with CIDR, pretty much any IP can end up being reserved
as being either the network base or the broadcast for some sufficiently
small network.

There is an RFC for using /31's on point-to-point links, that removes
the reserved status from the two addresses.
--
I've been working on a kernel
All the livelong night.
I've been working on a kernel
And it still won't work quite right. -- J. Benson & J. Doll
 
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Jeremy McMasters
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Posts: n/a
 
      09-22-2004
What I am thinking, of what Rod wrote about his firewall filtering out .0
and .255 ip address's even though I have another /21 that can access the
same site I will have to rule this out. Its an odd occurance and I am
actually quiet stumped on this. lets say I have 207.255.136.0 /21, this
block with any ip address .0 or .255 is blocked at microsoft or ebay. But I
have 24.197.56.0 /21 that can go to any site with out incident. All my
reverse's are in order. .0 and .255 should be viable /21 ip addresses as
long as it is not the beginning and ending ip address of the /21.

Jeremy





"Jeremy McMasters" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> I am curious to whether anyone on this board has ever ran into a

problem
> where if you have a .0 or a .255 as an ip address (last octet) that you
> can't access websites like www.ebay.com or www.microsoft.com. I have a

/21
> that I have handling otu ip address's to subscribers using Cisco Network
> Registrar. I am wondering if there is something I need to do on Layer 3

or
> this needs to be escalated to my upstream-provider
>
>



 
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S. Gione
Guest
Posts: n/a
 
      09-23-2004
Just my opinion, but I don't think that either of these addresses should be
used. For a 21-bit mask, they are both network addresses (last 11 bits
zero).

I don't know where in your (or outside on the route) it's happening, but it
appears that some classful constraints are being applied. This might be why
the 207 fails (class C in classful) and the 24.197.56.0 gets thru (because
it would be valid for a mask of 20 bits or less).

"Jeremy McMasters" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> What I am thinking, of what Rod wrote about his firewall filtering out .0
> and .255 ip address's even though I have another /21 that can access the
> same site I will have to rule this out. Its an odd occurance and I am
> actually quiet stumped on this. lets say I have 207.255.136.0 /21, this
> block with any ip address .0 or .255 is blocked at microsoft or ebay. But

I
> have 24.197.56.0 /21 that can go to any site with out incident. All my
> reverse's are in order. .0 and .255 should be viable /21 ip addresses as
> long as it is not the beginning and ending ip address of the /21.
>
> Jeremy
>
>
>
>
>
> "Jeremy McMasters" <(E-Mail Removed)> wrote in message
> news:(E-Mail Removed)...
> > I am curious to whether anyone on this board has ever ran into a

> problem
> > where if you have a .0 or a .255 as an ip address (last octet) that you
> > can't access websites like www.ebay.com or www.microsoft.com. I have a

> /21
> > that I have handling otu ip address's to subscribers using Cisco Network
> > Registrar. I am wondering if there is something I need to do on Layer 3

> or
> > this needs to be escalated to my upstream-provider
> >
> >

>
>



 
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