From: Yasser Aly (blackyeyes00@hotmail.com)
Date: Fri Feb 20 2004 - 15:28:30 GMT-3
Hi group,
Would you kindly share us with your visions on time saving techniques to
detect a routing loop ?
Regards,
Yasser
>From: "Michael Snyder" <msnyder@revolutioncomputer.com>
>You don't.
>
>This is simply checking the routing table for present routes.
>
>A hybrid technique would be needed to test reachability and routing
>table contents.
>
>
>
>-----Original Message-----
>From: Yasser Aly [mailto:blackyeyes00@hotmail.com]
>Sent: Friday, February 20, 2004 12:10 PM
>To: msnyder@revolutioncomputer.com; ccielab@groupstudy.com
>Cc: ahmed.mustafa@sbcglobal.net
>Subject: RE: Checking the Lab Work
>
>
>Hello,
>
> I have two questions:
>
>1) How to verify reachability for all your routes on the 3550 switch. I
>tried tclsh but the command was not accepted on it ?
>
>2) If you rely on the procedure described below it will be misleading.
>Example, if you have a routing loop for a certain route, you will have a
>
>route in the sh ip route for the looped route, however you will not be
>able
>to detect that it is looped and might think everything is ok if you rely
>
>only that the route show up in the routing table.
>
>This leads to the question: How to detect that you have a routing loop
>with
>one of your routes ?
>
>Regards,
>Yasser
>
> >From: "Michael Snyder" <msnyder@revolutioncomputer.com>
> >
> >Here's a repost of the igp grading script I wrote last year.
> >
> >It's for people with a rack full of 2500`s and don't have access to
> >tclsh.
> >
> >-----------------------------------------------------------------------
>-
> >--
> >
> >I was working on a lab this morning, and for some reason my three way
> >redistribution wasn't working.
> >
> >After jumping router to router for 30 minutes, I thought gee I wish I
> >had a command to show me every missing route.
> >
> >I made a script to do this; I'll walk you thru how I composed the
> >script. It took me about 5 minutes.
> >
> >Here's some benefits of the script.
> >
> >1) Can't be fooled by a default route.
> >2) Can't be fooled by the wrong mask size.
> >3) Assumes that the route should be present.
> >
> >Generates output only if it's missing.
> >
> >
> >-----------------------------------------------------------------------
>-
> >--
> >
> >First I did a `show run | i ip address`
> >
> >And pasted the results to notepad from every router.
> >
> >
> >-----------------------------------------------------------------------
>-
> >--
> >
> > ip address 170.1.1.1 255.255.255.255
> > ip address 150.50.200.1 255.255.255.0
> > ip address 170.1.150.1 255.255.255.0
> >
> > ip address 170.1.2.2 255.255.255.255
> > ip address 172.16.1.1 255.255.255.0
> > ip address 172.16.3.1 255.255.255.0
> > ip address 172.16.2.1 255.255.255.0
> > ip address 172.16.0.1 255.255.255.0
> > no ip address
> > no ip address
> > ip address 170.1.100.2 255.255.255.0
> > ip address 170.1.150.2 255.255.255.0
> > ip address 150.50.9.5 255.255.255.252
> >
> > ip address 170.1.4.4 255.255.255.255
> > ip address 192.168.10.1 255.255.255.0
> > no ip address
> > ip address 170.1.100.4 255.255.255.0
> > no ip address
> >
> > ip address 170.1.5.5 255.255.255.255
> > ip address 170.1.200.5 255.255.255.224
> > no ip address
> > ip address 170.1.100.5 255.255.255.0
> > no ip address
> > no ip address
> >
> > ip address 170.1.6.6 255.255.255.255
> > ip address 170.1.200.6 255.255.255.224
> > no ip address
> > ip address 170.1.100.6 255.255.255.0
> > ip address 170.1.32.6 255.255.255.0
> > no ip address
> >
> > ip address 170.1.7.7 255.255.255.255
> > ip address 170.1.200.7 255.255.255.224
> > ip address 170.1.24.7 255.255.255.0
> >
> > ip address 170.1.8.8 255.255.255.255
> > ip address 150.50.4.8 255.255.255.0
> > ip address 170.1.24.8 255.255.255.0
> >
> > ip address 170.1.9.9 255.255.255.255
> > ip address 170.1.32.9 255.255.255.0
> > no ip address
> > ip address 170.1.15.9 255.255.255.192
> >
> >
> >
> >-----------------------------------------------------------------------
>-
> >--
> >
> >
> >Next in notepad, I did a replace all of `no ip address` with a null
> >string. Then I went thru the listing deleting the empty lines.
> >
> >
> >-----------------------------------------------------------------------
>-
> >--
> >
> > ip address 170.1.1.1 255.255.255.255
> > ip address 150.50.200.1 255.255.255.0
> > ip address 170.1.150.1 255.255.255.0
> > ip address 170.1.2.2 255.255.255.255
> > ip address 172.16.1.1 255.255.255.0
> > ip address 172.16.3.1 255.255.255.0
> > ip address 172.16.2.1 255.255.255.0
> > ip address 172.16.0.1 255.255.255.0
> > ip address 170.1.100.2 255.255.255.0
> > ip address 170.1.150.2 255.255.255.0
> > ip address 150.50.9.5 255.255.255.252
> > ip address 170.1.4.4 255.255.255.255
> > ip address 192.168.10.1 255.255.255.0
> > ip address 170.1.100.4 255.255.255.0
> > ip address 170.1.5.5 255.255.255.255
> > ip address 170.1.200.5 255.255.255.224
> > ip address 170.1.100.5 255.255.255.0
> > ip address 170.1.6.6 255.255.255.255
> > ip address 170.1.200.6 255.255.255.224
> > ip address 170.1.100.6 255.255.255.0
> > ip address 170.1.32.6 255.255.255.0
> > ip address 170.1.7.7 255.255.255.255
> > ip address 170.1.200.7 255.255.255.224
> > ip address 170.1.24.7 255.255.255.0
> > ip address 170.1.8.8 255.255.255.255
> > ip address 150.50.4.8 255.255.255.0
> > ip address 170.1.24.8 255.255.255.0
> > ip address 170.1.9.9 255.255.255.255
> > ip address 170.1.32.9 255.255.255.0
> > ip address 170.1.15.9 255.255.255.192
> >
> >
> >
> >
> >-----------------------------------------------------------------------
>-
> >--
> >
> >
> >This lab uses a summary address of 172.16.0.0/22, so I chose to pull
>out
> >the 172.16.1.1/24 routes and use the summary instead.
> >
> >Here's a important part, I needed a unique post-delimiter on the ends
> >of the statements for text search and replace later. So I appended the
> >` char to the ends of the statements by hand. Each statement begins
>the
> >same `ip address` text, so I don't need a pre-delimiter here.
> >
> >
> >-----------------------------------------------------------------------
>-
> >--
> >
> >
> >
> > ip address 170.1.1.1 255.255.255.255 `
> > ip address 150.50.200.1 255.255.255.0 `
> > ip address 170.1.150.1 255.255.255.0 `
> > ip address 170.1.2.2 255.255.255.255 `
> > ip address 172.16.0.0 255.255.252.0 `
> > ip address 170.1.100.2 255.255.255.0 `
> > ip address 170.1.150.2 255.255.255.0 `
> > ip address 150.50.9.5 255.255.255.252 `
> > ip address 170.1.4.4 255.255.255.255 `
> > ip address 192.168.10.1 255.255.255.0 `
> > ip address 170.1.100.4 255.255.255.0 `
> > ip address 170.1.5.5 255.255.255.255 `
> > ip address 170.1.200.5 255.255.255.224 `
> > ip address 170.1.100.5 255.255.255.0 `
> > ip address 170.1.6.6 255.255.255.255 `
> > ip address 170.1.200.6 255.255.255.224 `
> > ip address 170.1.100.6 255.255.255.0 `
> > ip address 170.1.32.6 255.255.255.0 `
> > ip address 170.1.7.7 255.255.255.255 `
> > ip address 170.1.200.7 255.255.255.224 `
> > ip address 170.1.24.7 255.255.255.0 `
> > ip address 170.1.8.8 255.255.255.255 `
> > ip address 150.50.4.8 255.255.255.0 `
> > ip address 170.1.24.8 255.255.255.0 `
> > ip address 170.1.9.9 255.255.255.255 `
> > ip address 170.1.32.9 255.255.255.0 `
> > ip address 170.1.15.9 255.255.255.192 `
> >
> >
> >
> >
> >-----------------------------------------------------------------------
>-
> >--
> >
> >Here's the payoff. Using notepad, replace all `ip address` with `show
> >ip route` Also replace our delimiting char ` with `| i not`
> >
> >
> >-----------------------------------------------------------------------
>-
> >--
> >
> > show ip route 170.1.1.1 255.255.255.255 | i not
> > show ip route 150.50.200.1 255.255.255.0 | i not
> > show ip route 170.1.150.1 255.255.255.0 | i not
> > show ip route 170.1.2.2 255.255.255.255 | i not
> > show ip route 172.16.0.0 255.255.252.0 | i not
> > show ip route 170.1.100.2 255.255.255.0 | i not
> > show ip route 170.1.150.2 255.255.255.0 | i not
> > show ip route 150.50.9.5 255.255.255.252 | i not
> > show ip route 170.1.4.4 255.255.255.255 | i not
> > show ip route 192.168.10.1 255.255.255.0 | i not
> > show ip route 170.1.100.4 255.255.255.0 | i not
> > show ip route 170.1.5.5 255.255.255.255 | i not
> > show ip route 170.1.200.5 255.255.255.224 | i not
> > show ip route 170.1.100.5 255.255.255.0 | i not
> > show ip route 170.1.6.6 255.255.255.255 | i not
> > show ip route 170.1.200.6 255.255.255.224 | i not
> > show ip route 170.1.100.6 255.255.255.0 | i not
> > show ip route 170.1.32.6 255.255.255.0 | i not
> > show ip route 170.1.7.7 255.255.255.255 | i not
> > show ip route 170.1.200.7 255.255.255.224 | i not
> > show ip route 170.1.24.7 255.255.255.0 | i not
> > show ip route 170.1.8.8 255.255.255.255 | i not
> > show ip route 150.50.4.8 255.255.255.0 | i not
> > show ip route 170.1.24.8 255.255.255.0 | i not
> > show ip route 170.1.9.9 255.255.255.255 | i not
> > show ip route 170.1.32.9 255.255.255.0 | i not
> > show ip route 170.1.15.9 255.255.255.192 | i not
> >
> >
> >-----------------------------------------------------------------------
>-
> >--
> >
> >Ok, lets try it on R4.
> >
> >I use four terminal windows, so I cut and paste to all four at once,
>and
> >read the results when done. It's really telling when you see the same
> >missing route on three of the four routers.
> >
> >Another thing, if route shouldn't show up on any router, replace the `i
> >not` with `e not`
> >
> >-----------------------------------------------------------------------
>-
> >--
> >
> >R4#
> >R4#
> >R4# show ip route 170.1.1.1 255.255.255.255 | i not
> >R4# show ip route 150.50.200.1 255.255.255.0 | i not
> >% Network not in table
> >
> >R4# show ip route 170.1.150.1 255.255.255.0 | i not
> >R4# show ip route 170.1.2.2 255.255.255.255 | i not
> >R4# show ip route 172.16.0.0 255.255.252.0 | i not
> >R4# show ip route 170.1.100.2 255.255.255.0 | i not
> >R4# show ip route 170.1.150.2 255.255.255.0 | i not
> >R4# show ip route 150.50.9.5 255.255.255.252 | i not
> >% Network not in table
> >
> >R4# show ip route 170.1.4.4 255.255.255.255 | i not
> >R4# show ip route 192.168.10.1 255.255.255.0 | i not
> >R4# show ip route 170.1.100.4 255.255.255.0 | i not
> >R4# show ip route 170.1.5.5 255.255.255.255 | i not
> >R4# show ip route 170.1.200.5 255.255.255.224 | i not
> >% Subnet not in table
> >
> >R4# show ip route 170.1.100.5 255.255.255.0 | i not
> >R4# show ip route 170.1.6.6 255.255.255.255 | i not
> >R4# show ip route 170.1.200.6 255.255.255.224 | i not
> >% Subnet not in table
> >
> >R4# show ip route 170.1.100.6 255.255.255.0 | i not
> >R4# show ip route 170.1.32.6 255.255.255.0 | i not
> >R4# show ip route 170.1.7.7 255.255.255.255 | i not
> >% Subnet not in table
> >
> >R4# show ip route 170.1.200.7 255.255.255.224 | i not
> >% Subnet not in table
> >
> >R4# show ip route 170.1.24.7 255.255.255.0 | i not
> >% Subnet not in table
> >
> >R4# show ip route 170.1.8.8 255.255.255.255 | i not
> >% Subnet not in table
> >
> >R4# show ip route 150.50.4.8 255.255.255.0 | i not
> >% Network not in table
> >
> >R4# show ip route 170.1.24.8 255.255.255.0 | i not
> >% Subnet not in table
> >
> >R4# show ip route 170.1.9.9 255.255.255.255 | i not
> >R4# show ip route 170.1.32.9 255.255.255.0 | i not
> >R4# show ip route 170.1.15.9 255.255.255.192 | i not
> >R4#
> >
> >
> >-----------------------------------------------------------------------
>-
> >--
> >
> >There's my missing routes!!! For some reason rip isn't making it to
> >ospf on R4.
> >
> >
> >-----Original Message-----
> >From: Ahmed Mustafa [mailto:ahmed.mustafa@sbcglobal.net]
> >Sent: Wednesday, February 18, 2004 9:44 PM
> >To: ccielab@groupstudy.com
> >Subject: Checking the Lab Work
> >
> >Guys,
> >
> >What is the easiest way to check the lab work. This is the most
> >important
> >task especially if one is taking a real lab.
> >
> >I mean what is the best way to find out that you are seeing all the
> >routes in
> >your routers that are you are supposed to be seeing, and pinging all
>the
> >interfaces making sure that there is no loss of connectivity. I know
> >that one
> >can do this from each router to see what routes are seen and whether
> >they are
> >pingable
> >Is there any work around?
> >
> >Thanks,
> >
> >Ahmed
> >
> >_______________________________________________________________________
> >Please help support GroupStudy by purchasing your study materials from:
> >http://shop.groupstudy.com
> >
> >Subscription information may be found at:
> >http://www.groupstudy.com/list/CCIELab.html
> >
> >_______________________________________________________________________
> >Please help support GroupStudy by purchasing your study materials from:
> >http://shop.groupstudy.com
> >
> >Subscription information may be found at:
> >http://www.groupstudy.com/list/CCIELab.html
>
>_________________________________________________________________
>MSN 8 helps eliminate e-mail viruses. Get 2 months FREE*.
>http://join.msn.com/?page=features/virus&pgmarket=en-ca&RU=http%3a%2f%2f
>join.msn.com%2f%3fpage%3dmisc%2fspecialoffers%26pgmarket%3den-ca
>
>_______________________________________________________________________
>Please help support GroupStudy by purchasing your study materials from:
>http://shop.groupstudy.com
>
>Subscription information may be found at:
>http://www.groupstudy.com/list/CCIELab.html
This archive was generated by hypermail 2.1.4 : Fri Mar 05 2004 - 07:13:51 GMT-3