From: Vincent Lee (mcne95@xxxxxxxxx)
Date: Fri Mar 15 2002 - 22:42:44 GMT-3
Thank you for all the input.
If our company applies for a block of class C IP
address, how can we won't have any down time on the
Web servers and SMTP servers when we switch current IP
addresses to the new class C IP address. After we
change the IP addresses in the DNS server, the change
will take up to 24 hours or even more.
thank you
--- "Howard C. Berkowitz" <hcb@gettcomm.com> wrote:
> At 8:05 PM +0000 3/15/02, Brian Lodwick wrote:
> >We had a customer that was on our old old network.
> This network had
> >a different AS and addressing. This customer wanted
> to move to a
> >newer solution we offered, but wanted to keep the
> existing
> >addressing structure. This wasn't much an issue,
> because accoring to
> >our policy we were allowed to advertise any
> customer net above a
> >/24, and they had a /22. The old network advertised
> an aggregate so
> >this more specific range was preferred and the
> transition worked.
> >The reason I went into this whole schpeal is that
> like you said if
> >you get addressing space from one of the providers,
> and you get
> >approval to advertise that range out of the other
> provider as well,
> >you will have sort of a primary / secondary
> solution and will not be
> >able to achieve load sharing.
>
> Untrue. Now, both providers MUST agree to it. Let's
> say there is a
> /24 from provider A's space, which comes out of
> their /16. Provider
> B certainly can advertise the /24, although it
> wouldn't be done in
> usual practice without agreement with A.
>
> Now, the subtle point. Once provider A agrees to let
> provider B
> advertise the more-specific, provider A _must_
> advertise both the /16
> _and_ a /24 for each multihomed customer.
> Otherwise, as you suggest,
> all traffic would take the more-specific advertised
> by provider B.
>
> >Reason being is the provider you get your
> addressing space from will
> >most likely be advertising to the NAP an aggregate
> so the other one
> >that allows you to advertise the /24 will always be
> preferred over
> >the aggregate. If redundancy is the only
> requirement you would be
> >fine if you had one provider give you addressing
> space and you
> >advertised it out of the other provider as well.
> >I wasn't aware you couldn't purchase a /24 from
> ARIN. I'm not really
> >too knowledgeable on that type of thing. I only cut
> addressing space
> >from our nets when needed for our customers. I have
> never gone out
> >and tried to purchase addressing space from ARIN.
>
> "Purchase" really isn't the right word. Allocation
> is the correct
> term for handing out provider-independent address
> space. ARIN, RIPE
> NCC, and APNIC won't just hand out space to anyone
> that brings them
> money; they will need to see a justification and
> will review your
> efficient utilization if you ask for more.
>
> You can multihome to multiple POPs of the same
> provider, with
> provider-assigned address space. See RFC 1998. You
> can even do this
> with PI space and a private ASN, although it's sort
> of a kludge. See
> RFC 2270.
>
> There are also engineered solutions where two
> providers originate the
> same prefix, which is technically an "inconsistent
> AS" but is not
> uncommon and doesn't really create problems.
>
> The address registries also make no guarantees if
> your address space
> will be globally routable. There is a trend to
> reduce the number of
> prefix length filters, but that also means the
> current routing
> architecture will run out of steam in 4-8 years.
> I'm involved in the
> Internet Research Task Force effort that's just
> starting to look at
> "what comes after the BGP architecture."
>
> >
> >BTW I have a neat HSRP & BGP redundancy solution to
> fix the downfall
> >of using this combination if you'd like to hear
> about it?
> >
> >
> >>From: Vincent Lee <mcne95@yahoo.com>
> >>Reply-To: Vincent Lee <mcne95@yahoo.com>
> >>To: Brian Lodwick <xpranax@hotmail.com>,
> wade.edwards@powerupnetworks.com
> >>CC: ccielab@groupstudy.com
> >>Subject: RE: OT: Change primary ISP from PacBell
> to Quest
> >>Date: Fri, 15 Mar 2002 11:09:07 -0800 (PST)
> >>
> >>Where can we apply for a class C IP address? ARIN
> >>only sell a larger block IP address. I believe if
> we
> >>want multihomed with different ISPs (AS), we need
> to
> >>setup BGP with both ISPs as peering.
>
> ARIN and the other registries will generally
> allocate /24 if you can
> show them contracts with two upstream providers, at
> least 50%
> utilization of your current address space, and
> various other
> justifications.
>
> You will probably need an AS number as well for
> general-case
> multihoming. There are requirements there. RIPE NCC,
> for example,
> requires that you write out your routing policy in
> RPSL and put it in
> the routing registry; this is optional but
> recommended for ARIN.
>
> Note that the address and routing data bases are
> separate.
>
> >>
> >>thanks
> >>
> >>--- Brian Lodwick <xpranax@hotmail.com> wrote:
> >>> The organization I work for will only allow it
> if
> >>> the space is /24 or
> >>> larger.
> >>>
> >>> >>>Brian
> >>>
> >>>
> >>> >From: "Wade Edwards"
> >>> <wade.edwards@powerupnetworks.com>
> >>> >Reply-To: "Wade Edwards"
> >>> <wade.edwards@powerupnetworks.com>
> >>> >To: "Vincent Lee" <mcne95@yahoo.com>
> >>> >CC: <ccielab@groupstudy.com>
> >>> >Subject: RE: OT: Change primary ISP from
> PacBell to
> >>> Quest
> >>> >Date: Fri, 15 Mar 2002 12:16:17 -0600
> >>> >
> >>> >To get a true backup you have to apply for
> your own
> >>> address space that
> >>> >you can announce to both PacBell and Qwest.
> If you
> >>> are using address
> >>> >space from both PacBell and Qwest then they
> will
> >>> not allow you to
> >>> >announce their addresses through a different
> >>> provider. You can ask if
> >>> >they will but this is usually against their
> routing
> >>> policy. So you
> >>> >don't need BGP. Just use static routing.
> >>> >
> >>> >L8r.
> >>> >
> >>> > -----Original Message-----
> >>> >From: Vincent Lee [mailto:mcne95@yahoo.com]
> >>> >Sent: Friday, March 15, 2002 11:49 AM
> >>> >To: Brian Lodwick; dmadlan@qwest.com
> >>> >Cc: ccielab@groupstudy.com
> >>> >Subject: Re: OT: Change primary ISP from
> PacBell to
> >>> Quest
> >>> >
> >>> >We are using the PacBell and already ordered
> the
> >>> Qwest
> >>> >Circuit.
> >>> >Two perimeter routers configed with HSRP and
> they
> >>> are
> >>> >only connect to Pacbell at this moment.
> >>> >
> >>> >We are going to keep PacBell as secondary with
> a
>
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