From: ccielab@cox.net
Date: Sun Feb 08 2004 - 14:52:20 GMT-3
Thomas,
Great advice, what is the 'tcp compression' issue?
thanks
>
> From: "Thomas Larus" <tlarus@cox.net>
> Date: 2004/02/08 Sun PM 12:05:52 EST
> To: "Rahul Barua" <rahulbarua@touchtelindia.net>, <ccielab@groupstudy.com>
> Subject: Re: CCIE -lab - scripts .
>
> That is a great post about scripts, and those were great aliases, too.
> Still, I would like to remind CCIE candidates that ping scripts may not be
> adequate tests of your network, so do not rely too much on them.
>
> You can break your network in ways that a ping script will not catch, by
> misconfiguring extended access-lists or configuring TCP compression on only
> one side of a link. Also, a ping script could indicate problems that are
> not really problems. For example, if you are advertising only loopback
> addresses in BGP (and you are relying on BGP for connectivity between the
> two routers in question), a ping from one router to another might fail
> unless you use extended ping and specify as source the loopback whose
> network is advertised by BGP so that it reaches the destination router.
>
> I recognize that most CCIE candidates are well aware of these issues, but I
> mention them for the few that have not yet been exposed to them and for
> those who are forgetful like me. I did not know about the TCP compression
> issue until I attended a boot camp. It is important to think about what is
> going on at layers above Layer 3, and all the emphasis on security nowadays
> is probably helping folks to think in more precise terms about what is going
> on at the Transport layer and above.
>
> I tend to use Telnet a lot in my practice scenarios, because it lends itself
> to testing. Testing using Telnet reminds my readers (and myself) to focus
> on more than mere Layer 3 connectivity. You would not believe how easy it
> is to forget that point about specifying source interface for extended ping.
> Just the other day, I thought, for a few minutes, that I had a problem when
> I was testing part of a scenario, but then remembered that I should only be
> able to ping loopback to loopback.
>
> Best regards,
>
> Tom Larus, CCIE #10,014
> Author of CCIE Warm-Up: Advice and Learning Labs
>
>
>
> ----- Original Message -----
> From: "Rahul Barua" <rahulbarua@touchtelindia.net>
> To: <ccielab@groupstudy.com>
> Sent: Saturday, February 07, 2004 12:01 PM
> Subject: CCIE -lab - scripts .
>
>
> > Dear Kasturi ,
> > Any help is always appreciated . any ways i am yet far away from 8hr
> > sessions.
> > wat i really wanted to ask for is small tricks n tips , well one of my
> ccie
> > freinds says
> > ccie is a fight against time ,the more u save ,the better coz u can review
> ur
> > configs .
> > Th script he asked me to use is :
> >
> > tclsh
> > foreach test {
> > 10.1.1.1
> > 10.2.2.2
> > 10.3.3.3
> > 10.4.4.4
> > } {ping $test} ps: works on 12.2t and above n mostly seen on 26xx (yet to
> see
> > a 25xx with it)
> >
> > This way for checking end to end connectivity i don't have to type in more
> key
> > storkes .
> > just one script and test it on all the routers well saves 15 min , just
> type
> > all ips in
> > a note pad along with the script and boy u r not waiting for a ping to
> finish
> > to resume another one .
> > well i just wanted to know if there are other similar short tricks that
> could
> > make life easier .
> > i bet this script will sure help a lotta guys who din't know {if people
> like
> > that exist on this forum}.
> > well i use a long list of alias commands and practice to type them in just
> abt
> > 10 min .so that i can save time .
> > well i have made this post before but just if someone missed it here it is
> > again .
> >
> > alias configure ac alias configure
> > ac ae alias exec
> > ac ai alias interface
> > ac as alias subinterface
> >
> > ai i ip address
> > ai ns no shut
> > ai cr clock rate
> > ai e exit
> > ai ef encapsulation frame-relay
> > ai ep encapsulation ppp
> > ai fm frame-relay map ip
> > ai fi frame-relay interface-dlci
> > ai nfi no frame-relay inver
> > ai frts frame-relay traffic-shap
> >
> >
> > as i ip address
> > as ns no shut
> > as cr clock rate
> > as e exit
> > as ef encapsulation frame-relay
> > as ep encapsulation ppp
> > as fm frame-relay map ip
> > as fi frame-relay interface-dlci
> > as nfi no frame-relay inver
> > as frts frame-relay traffic-shap
> >
> > ac r router rip
> > ac e router eigrp
> > ac o router ospf
> > ac is router isis
> > ac b router bgp
> > ac a access-list
> > ac na no access-list
> > ac ia ip access-list
> > ac nia no ip access-list
> > ac i interface
> > ac rm route-map
> > ac nrm no route-map
> > ac di default interface
> >
> >
> > ae a sh access-list
> > ae b sh runn | begin
> > ae c conf t
> > ae sr sh runn | e alias
> > ae s sh ip inter brief | e unass
> > ae si sh ip route
> > ae i sh runn interface
> > ae sp sh ip protocols
> > ae sf sh frame-relay
> > ae sn sh isdn
> > ae sa sh atm
> > ae so sh ip ospf
> > ae se sh ip eigrp
> > ae sb sh ip bgp
> > ae sm sh ip mroute
> > ae ci clear ip route *
> > ae co clear ip ospf process
> > ae cb clear ip bgp *
> > ae sb sh ip bgp
> > ae nd undebug all
> > ae d debug
> > ae dci debug condition inteface
> > ae ndc no debug condition interface
> > ae sc show controller serial
> >
> > ae v sh vlan
> > ae sis sh interface status
> > ae st sh inter trunk
> > ac vd vlan database
> > ae sec show ether
> >
> > no ip domain lookup
> >
> > line con 0
> > logg sync
> > exec-t 0 0
> >
> > lin vty 0 4
> > logg sync
> > exec-t 0 0
> >
> >
> > Regards
> >
> > Rahul Barua .
> >
> > " Do,Or do not.There is no try . " - Yoda .
> >
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