From: ccie2be (ccie2be@nyc.rr.com)
Date: Thu Mar 17 2005 - 14:48:36 GMT-3
Thanks Jongsoo for your response.
Looking at your acl 100, how would I write, "R-B or R-C or beyond network"
in one line since there are a number of major networks and I would like to
create an acl where it didn't matter how many major networks there were or
if additional major networks were added in the future.
The problem I have with specifying the destination networks in an acl is
that seems to be an error prone way to go and if new networks were added the
acl would have to be updated.
Also, it looks like you're mixing policy routing with MQC.
The service-policy command is an MQC command but the route-map is used with
policy routing.
Can that be done?
If so, that's news to me (good news, perhaps, but something I was totally
unaware of.)
Thanks again, tim
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
Jongsoo.Kim@Intelsat.com
Sent: Thursday, March 17, 2005 12:32 PM
To: ccie2be@nyc.rr.com; ccielab@groupstudy.com
Subject: RE: MQC vs Policy Routing
Tim
My understanding is that you need to send traffic from vlan A to R-B or R-C
or beyond and with prec = 3 toward Rc or its PVC.
If you use extend ACL, you can define source, destination, prec in one line.
I am guess the fonig amy be something like this
access-list 100 permit ip "vlan A network" "R-B or R-C or beyond network"
precedence 3
route-map 10 IF-IP-PREC-3-GOTO-RC
match ip address 100
set ip next-hop R-C R-B ===> (I think this makes if R-C is not available,
then R-B will be the next hop.( I am not 100 % sure))
route-map 20 IF-IP-PREC-3-GOTO-RC ===> (this line is not necessary for
policy routing as its default behavior is permit, which is opposite to
rouet-map)
int f/r p2m
service-policy out IF-IP-PREC-3-GOTO-RC
Regards
Jongsoo
-----Original Message-----
From: ccie2be [mailto:ccie2be@nyc.rr.com]
Sent: Thursday, 17 March, 2005 11:55 AM
To: Group Study
Subject: MQC vs Policy Routing
Hi guys,
This problem stumped me. I didn't like either of the 2 solutions that came
to mind and would like to hear your thoughts.
=============================
Figure 1
/ -- R-B
| ---- e0/0 R-A -- p2m f/r other networks with different
major network addresses
\ -- R-C
==============================
Figure 2
R-A e0/0 ---- vlan 1 ------ R-d ----- R-e
==============================
R-A is connected to vlan 1 via it's e0/0 interface and to R-d via vlan 1 and
other subnets beyond that. (Fig 2)
R-A is also connected to R-B and R-C via p2m f/r and can reach other
networks behind R-B and R-C (Fig 1)
I want R-A to forward packets that originate on vlan 1 and are heading to
R-B or R-C or beyond and have an ip prec of x to take the pvc to R-C if it's
available.
If the pvc or R-C is down, take the other pvc. All networks behind R-B or
R-C can be reached via either pvc.
I'm not sure how to config this.
I thought of policy routing but this was the problem I couldn't figure out.
Suppose packets originating on vlan 1 weren't suppose to head towards R-B or
R-C? Wouldn't they just end up going to R-C or R-B only for these routers
to send them back to R-A. ? And, thus waste bandwidth?
Here's the pseudo code:
route-map 10 IF-IP-PREC-3-GOTO-RC
match ip-prec-3 and source = vlan1
set ip next-hop R-C
route-map 20 IF-IP-PREC-3-GOTO-RC
***********************************************
The other solution I thought of was to use MQC:
Assume the dlci to R-B = dlci-B and the dlci to R-C = dlci-C.
Here's the pseudo code:
access-list 100 permit ip vlan1 any prec 3
class-map match-all IP-PREC
match int e0/0 <-- Is this needed?
match ip address 100
policy-map IP-PREC
class IP-PREC
set fr-dlci <pvc-C>
int f/r p2m
service-policy out IP-PREC
*****************************************************
I never used the set fr-dlci command before and so I'm not 100% sure this
solution actually works but I pretty sure it does. (I put an acl on R-C and
then did some pings and saw the matching packets go up but I didn't do any
other testing.)
Q?
Will both solutions actually work?
Is the MQC solution better?
Is there a better solution I didn't think of?
TIA, Tim
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