RE: BGP no sync and Bootcamp Labs

From: Steven Weber (itweber@xxxxxxxxxxxxx)
Date: Sun Mar 04 2001 - 20:50:33 GMT-3


   

just thought I mention the point, sorry if I confused anybody

Steve

----- Original Message -----

From: Bowen,
Shawn

To: Groupstudy

Sent: 3/4/01 6:09:21 PM

Subject: RE: BGP no sync and Bootcamp
Labs

True, true. I didn't want to mention that cause I was worried
about the

implications of not understanding it:-) It's not usually what was meant
to

be done to inject a whole class A into BGP on accident:-) Aggregates
also

work nicely for this.

Shawn

-----Original Message-----

From: Steven Weber [mailto:itweber@earthlink.net ]

Sent: Sunday, March 04, 2001 4:58 PM

To: Groupstudy; Bowen, Shawn

Subject: RE: BGP no sync and Bootcamp Labs

I just wanted to add to Shawn's statement, as this topic is worthy of

discussion because it is part of understanding the core of what bgp
is

about. I just wanted to add that you can also use the classful
network

address in your network statement without having to match on a BIT by
BIT

basis the only drawback is that everything in your routing table under
that

classful prefix ends up getting advertised.

----- Original Message -----

From: Bowen, mailto:sbowen@neteffectcorp.com Shawn

To: Groupstudy mailto:sbowen@neteffectcorp.com

Sent: 3/4/01 3:59:12 PM

Subject: RE: BGP no sync and Bootcamp Labs

No sync comes in handy when you do not want to have explicit BGP
network

statements. BGP will only use your network statement IF and ONLY
IF your

BGP network statement coincides with a BIT for BIT match in your
interior

routing protocol (forget about no-sync for a second). Now, this
is all cool

and dandy unless you are say using EIGRP and it summarizes the networks
for

you by default. Then when your BGP statement uses the actual
match it will

not match BIT for BIT and will not be included in BGP. No Sync
is one way

around this, another is a static route for your network to NULL on
the

router you want to inject into BGP. You will then go to the
longest match

rule and the NULL route will be ignored and BGP will get to inject it

without no-sync. As long as your interior routing protocol has
the route in

its tables, and your BGP network statement matches it BIT for BIT (IP
and

MASK) then it will fly.

Shawn

-----Original Message-----

From: crl [ mailto:cisco@crl.fdns.net mailto:mailto:cisco@crl.fdns.net
]

Sent: Sunday, March 04, 2001 3:15 PM

To: Groupstudy

Subject: BGP no sync and Bootcamp Labs

Just finished my first run through Bootcamp Lab #6. Not a very tough
one

anymore if you skip the protocols that are irrelevant to today's lab...
To

shake things up a bit, I decided to try to get the BGP configs all
working

without using the no sync command (I know that it wasn't outlawed in
the

lab.)

Well I had a terrible time of this. I admit, BGP is a weak area for me,
and

I likely won't be doing anymore Bootcamp labs until I polish my BGP
core

knowledge. Has anyone else done these labs leaving syncronization enabled?
I

could get about half my routes into the routing table, but the other half
I

just couldn't.

I know it's been brought up before, but if the odds are that the lab
is

going to outlaw the "no sync" command, why do so many people turn it on
when

doing scenarios?

That's my thought of the day...



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