Hi Jaffar,

Jaffar the Prince wrote:

> i have 2 questions, for the same cisco 2509 router:
> set up some routes to make it go through the interface that i want ? i
> have ip's from both halfs on the eth0 and also on async1-8. i _dont_ want
> all outgoing traffic to go through one default interface, and only
> incoming to be routed. i have already tried the following:

You need to implement policy routing in order to route the data according
to the source address, instead of the destination (the default). This
involves setting up access lists, defining which packets you are interested
in, then declaring a route map and applying this to the LAN interface of
the router (where the packets arrive from).

The example below is for your setup, if I read you message correctly:

!--- Cut ---
! Setup access lists
! these route based on source address
! (the masks are calculated as the inverted subnet mask)
!
! Line #1 - subnet x.x.x.0 to x.x.x.127
!
no access-list 120
access-list 120 permit ip x.x.x.0 0.0.0.127 any
!
!  Line #2 - subnet x.x.x.128 to x.x.x.255
!
no access-list 121
access-list 121 permit ip x.x.x.128 0.0.0.127 any
!
!
! Policy route definition
!
! route map can be called anything you want, here I use 'MultiLine'
no route-map MultiLine
!
! If you want to modify each entry, you must delete it first
no route-map MultiLine permit 10
route-map MultiLine permit 10
 match ip address 120
 set ip default next-hop ip.of.peer.of.serial.0
!
no route-map MultiLine permit 20
route-map MultiLine permit 20
 match ip address 121
 set ip default next-hop ip.of.peer.of.serial.1
!
!
interface Ethernet0
 ip policy route-map MultiLine
!
!
end

!--- Cut ---

(this will give errors the first time you run it if the access-lists/route
map
do not exist, this is normal).
 
The route map is applied to the interface where the outgoing data will
arrive from on the router, e.g.:  The LAN interface.

You don't use the default route entries at all.

> 2. same cisco, one C class for now, maybe more classes in the future. i
> have about 10 machines on the LAN, and 3 async lines are 33.6 leased lines
> with no access lists defined. my provider told me that it is not good to
> make access lists, as they would load the cpu very high and it may slow

There isn't a rule of thumb you can apply, as it depends upon the router
model, the bandwidth being used on all the interfaces and what processes
are running (routing, bridging etc).  The above policy routing example
should not add much to the CPU consumption.

Sometimes you can lower the CPU requirements by increasing the buffers
allocated to each interface and increasing the size of the In/out queue. 
You would have to look at the interface (sh int) and buffer (sh buff) info
to determine this.

-- 
 
 
Simon Thornton
Network Communications Management

----------------------------------------------------------------------
 Tel: (+33)49294-6428                        Amadeus Development Co.
 Fax: (+33)49294-6428                        155 Route Du Pin Montard
 BBS: (+33)49312-2155                        B.P 69
 Internet  : [EMAIL PROTECTED]        06902 Sophia Antipolis
 Compuserve: 100015,3641 (or 101511,3643)    CEDEX
 Fidonet   : 2:323/21                        France
----------------------------------------------------------------------
PGP Key (RSA):
http://pgpkeys.mit.edu:11371/pks/lookup?op=get&search=0xDBA2E709
begin:vcard 
n:Thornton;Simon
tel;fax:+33-49294-7922
tel;work:+33-49294-6428
x-mozilla-html:FALSE
org:Amadeus Development Company 
version:2.1
email;internet:[EMAIL PROTECTED]
title:Network Communications Manager
adr;quoted-printable:;;485 Route du Pin Montard=0D=0ABoite Postal 69;Sophia Antipolis;CEDEX;06902;France
note;quoted-printable:PGP Key (RSA): http://pgpkeys.mit.edu:11371/pks/lookup?op=3Dget&search=3D0xDBA2E709=0D=0A=0D=0A
x-mozilla-cpt:;-27280
fn:Thornton, Simon
end:vcard

Reply via email to