Jack
>From what I remember - SNAP and VC-Mux are two differnet encapsulations for
layer 3 protocols over ATM. I think VC-mux only allows one protocol/vc
while SNAP (because of the additional header) allows multiple layer 3
protocols/vc of course at an additional cost of the SNAP header which I
w
Hi Group,
Could you please light me up on the following comments:
"OSPF allows use of ATM VCmux encapsulation (so TCP acks fit in one ATM
cell);
IS-IS requires ATM SNAP encapsulation, forcing two-cell TCP acks (but Henk
Smit's NLPID hack fixes this)."
I have no clue what this means, please hel
Don't get me wrong. There are definite times to use ISIS, there are
definite times to use OSPF, and there are times either will work just
fine.
>Russ Meyer <[EMAIL PROTECTED]> wrote
>
>IS-IS is considered more stable because you can manually set the refresh
>time as far out as 18 + hours.
Thi
> You know sometimes the bottom of answers are so deep. It is hard to
>actually get to the bottom. Reading books from different authors I
>often notice contradicting stories. This gets to be quite confusing.
>
>Howard wrote:
>>>I wouldn't say US government requirements drove IS-IS. In fact,
>>
gt;>>Brian
>
>Go Alternet!
>
>>From: "Howard C. Berkowitz" <[EMAIL PROTECTED]>
>>Reply-To: "Howard C. Berkowitz" <[EMAIL PROTECTED]>
>>To: [EMAIL PROTECTED]
>>Subject: RE: IS-IS use??
>>Date: Thu, 16 Nov 2000 17:59:01 -0500
>
ot realize the difficulties we ran
into with Europe.
>>>Brian
Go Alternet!
>From: "Howard C. Berkowitz" <[EMAIL PROTECTED]>
>Reply-To: "Howard C. Berkowitz" <[EMAIL PROTECTED]>
>To: [EMAIL PROTECTED]
>Subject: RE: IS-IS use??
>Date: Thu, 16 No
"Howard C. Berkowitz" wrote:
>
> The direct ancestor of IS-IS is DECnet Phase IV routing, principally
> designed by Radia Perlman. DEC contributed its work to ISO, and
> IS-IS was initially developed as a pure OSI routing protocol (i.e.,
> for CLNP). IS-IS became the native IGP for DECnet Phase
-
Van: Peter Van Oene [mailto:[EMAIL PROTECTED]]
Verzonden: donderdag 16 november 2000 23:58
Aan: [EMAIL PROTECTED]
Onderwerp: Re: IS-IS use??
ISP's use IGP's (be they OSPF or IS-IS) for internal reachability (IBGP
peering is generally done on loopbacks and these networks need to be
adve
>"William Gragido" <[EMAIL PROTECTED]> wrote,
>IS-IS is most definetly still alive and kicking. The US military utilizes
>it, and it works very well. OSPF is a different animal, and Rik, I would
>disagree with your statement as to its scalability. IS-IS was designed to
>provide complete non-
ISP's use IGP's (be they OSPF or IS-IS) for internal reachability (IBGP peering is
generally done on loopbacks and these networks need to be advertised) and for next hop
resolution. Hence, all the perimeter BGP next hops will be advertised into the IGP so
that all IBGP speakers can properly po
ler'; [EMAIL PROTECTED]
>Sent: 11/16/00 5:38 PM
>Subject: RE: IS-IS use??
>
>IS-IS is most definetly still alive and kicking. The US military
>utilizes
>it, and it works very well. OSPF is a different animal, and Rik, I
>would
>disagree with your statement as to its
>Well, I believe that Cisco's take on this is that OSPF does not scale as
>well for very large networks as does IS-IS. At least so sayeth an
>instructor SE that I happen to know.
>
>Rik
It depends on how you define "large." Neither will handle extremely
large networks. Truly large networks us
>At 09:38 AM 11/16/00, Spolidoro, Guilherme wrote:
>
>>UUNet for example uses IS-IS on their core while the rest (or the majority)
>>of the ISPs use OSPF. I wonder why UUNet chosed for IS-IS instead of OSPF.
>>Maybe somebody on the list has an answer?
>>
>>Today I would chose OSPF over IS-IS becau
>Jack Walker wrote,
>Sorry for jumping into this.
>
>I think I agree with Bob that IS-IS is more like something a service
>provider should consider.
>OSPF is sufficient for enterprise network, at least I think so, just imagine
>a network with 3000 or more routers, how could we design a OSPF
>Chuck, I think this is a good question. I always looked for comparisons
>between IS-IS and OSPF and never really could find any good source (I mean,
>Doyle describe both protocols very well, but that's not what I'm looking
>for, I'm looking for large implementation descriptions, explaining
>probl
o IP. I'm sure most ISPs
that still use ATM would also use ATM to load balance traffic between links,
etc.
Does it help? :-)
Guilherme
-Original Message-
From: Jack Walker [mailto:[EMAIL PROTECTED]]
Sent: Thursday, November 16, 2000 3:41 PM
To: [EMAIL PROTECTED]
Subject: Re: IS-I
(CCIE
3xxx or so) agrees with.
I know absolutely nothing about IS-IS, so this is not my opinion, only a
repeat from those that know much more than me! ;-}
Rik
-Original Message-
From: William Gragido
To: 'Rik Guyler'; [EMAIL PROTECTED]
Sent: 11/16/00 5:38 PM
Subject: RE: IS-IS us
I am not familiar with the ISP enviroment at all.
When we say UUNet uses IS-IS on their core, do we mean that they
redistribute their BGP routes from their edge routers into IS-IS and
redistribute back into BGP and the far end edge routers?
Which means the edge routers are running BGP to learn cu
US
Government(ie Military), to accomadate its World Wide network.
-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of
Rik Guyler
Sent: Thursday, November 16, 2000 11:50 AM
To: '[EMAIL PROTECTED]'
Subject: RE: IS-IS use??
Well, I believe that Cisco
t: RE: IS-IS use??
At 09:38 AM 11/16/00, Spolidoro, Guilherme wrote:
>UUNet for example uses IS-IS on their core while the rest (or the
majority)
>of the ISPs use OSPF. I wonder why UUNet chosed for IS-IS instead of
OSPF.
>Maybe somebody on the list has an answer?
>
>Today I would c
At 09:38 AM 11/16/00, Spolidoro, Guilherme wrote:
>UUNet for example uses IS-IS on their core while the rest (or the majority)
>of the ISPs use OSPF. I wonder why UUNet chosed for IS-IS instead of OSPF.
>Maybe somebody on the list has an answer?
>
>Today I would chose OSPF over IS-IS because:
>
>
y perception that OSPF is the direction chosen by IETF, or at
>least
> > much more work is being done on OSPF than IS-IS
> > - OSPF is much more used than IS-IS, what makes easier to find people to
> > implement/support it
> >
> > Any inputs on that?
> >
> > Guilherme
&g
; much more work is being done on OSPF than IS-IS
> - OSPF is much more used than IS-IS, what makes easier to find people to
> implement/support it
>
> Any inputs on that?
>
> Guilherme
>
>
> -Original Message-
> From: McCallum, Robert [mailto:[EMAIL PROTECTED]]
>
IS-IS is used by a large percentage of 1st tier internet backbone providers. From
what I understand, it was chosen not for technical superiority over OSPF, but becuase
cisco's IS-IS code was more stable at the time. At present, IS-IS maintains a couple
advantages over OSPF in the ISP world.
Any inputs on that?
Guilherme
-Original Message-
From: McCallum, Robert [mailto:[EMAIL PROTECTED]]
Sent: Thursday, November 16, 2000 9:03 AM
To: 'Chuck Church'; '[EMAIL PROTECTED]'
Subject: RE: IS-IS use??
Chuck, come on IS-IS is an "OPEN" standard. I am
Chuck, come on IS-IS is an "OPEN" standard. I am the total opposite to you
as to say I have no been without it in 2 companies that I have worked for.
As for when you should use it - to be honest I am hearing of more and more
businesses using it as people are starting to "think" that IS-IS is m
26 matches
Mail list logo
