RE: Setting the DE bit in frame relay

From: ccie2be (ccie2be@nyc.rr.com)
Date: Tue Mar 01 2005 - 13:15:15 GMT-3


Eric et al;

I seem to recall that the router will NOT set the DE bit on traffic
originating from itself, only transit traffic.

I believe this can be checked by doing a show fram pvc <dlci #> on the
remote router. Just make sure you clear the counters first.

For example, since you're using OSPF, try setting the DE bit on just the
ospf traffic to see if that's possible.

HTH, Tim

-----Original Message-----
From: Eric Taylor [mailto:etaylor10@tampabay.rr.com]
Sent: Tuesday, March 01, 2005 10:56 AM
To: ccie2be; 'Bajo'; 'kuldip singh'
Cc: 'Wayne Bellward'; ccielab@groupstudy.com
Subject: RE: Setting the DE bit in frame relay

Here is a link for doing the MQC version

http://www.cisco.com/en/US/products/sw/iosswrel/ps1834/products_feature_guid
e09186a00800804ab.html#wp1058622

I just put it up in the lab and it appears to be working as advertised.

 class-map match-all ip-traffic
  match access-group 150
!
!
 policy-map SET-DE-IP
  class ip-traffic
   set fr-de
!
access-list 150 permit ip any any
!
interface Serial0/0
 ip address 172.16.10.4 255.255.255.0
 service-policy output SET-DE-IP <--- I want to set the DE bit on all
outbound traffic on all PVCs
 encapsulation frame-relay
 ip ospf network broadcast
 ip ospf priority 0
 frame-relay map ip 172.16.10.1 203
 frame-relay map ip 172.16.10.2 204 broadcast
 frame-relay map ip 172.16.10.3 203 broadcast
 frame-relay map ip 172.16.10.4 203
 no frame-relay inverse-arp
!

R4#sh policy-map int s0/0

 Serial0/0

  Service-policy output: SET-DE-IP

    Class-map: ip-traffic (match-all)
      59 packets, 5040 bytes
      5 minute offered rate 0 bps, drop rate 0 bps
      Match: access-group 150
      QoS Set
        fr-de
          Packets marked 59 <------ Shows that the packets are being
marked.

    Class-map: class-default (match-any)
      18 packets, 234 bytes
      5 minute offered rate 0 bps, drop rate 0 bps
      Match: any
R4#

HTH,
Eric

-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
ccie2be
Sent: Tuesday, March 01, 2005 10:23 AM
To: 'Bajo'; 'kuldip singh'
Cc: 'Wayne Bellward'; ccielab@groupstudy.com
Subject: RE: Setting the DE bit in frame relay

The frame congestion-management command you refer to is configured on the
frame relay switch not on endpoints of the frame circuit.

It should also be noted that when using the legacy global command to define
which traffic should have the DE bit set,

frame-relay de-list # protocol ip gt 512,

another command must also be used to associate this traffic with a dlci.
This command is

frame de-group # <dlci>e de-group # <dlci>

Think of this the same way you do with acl's: 1 command to define which
traffic is affected and a 2nd command to apply it to the interface. The big
difference is that when setting the DE bit, you need to apply the defined
traffic to a dlci, not an interface.

Also, you should be aware that the DE bit can also be set by using the new
MQC syntax.

HTH, Tim

-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of Bajo
Sent: Tuesday, March 01, 2005 9:54 AM
To: kuldip singh
Cc: Wayne Bellward; ccielab@groupstudy.com
Subject: Re: Setting the DE bit in frame relay

Wayne,

A search on the DOC-CD:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122cgcr/fwan
_c/wcffrely.htm

"When the output interface queue reaches or exceeds the ECN excess
threshold, all Frame Relay DE bit packets on all PVCs crossing that
interface will be marked with FECN or BECN, depending on their
direction of travel. When the queue reaches or exceeds the ECN
committed threshold, all Frame Relay packets will be marked with FECN
or BECN."

R1(config-if)#frame co?
congestion-management

R1(config-if)#frame co

R1(config-fr-congest)#?
Frame Relay congestion management configuration commands:
 default Set a command to its defaults
 exit Exit from frame relay congestion management configuration mode
 no Negate a command or set its defaults
 threshold Configure Frame Relay congestion thresholds
 <cr>

R1(config-fr-congest)#thres?
threshold

R1(config-fr-congest)#thres ?
 de Configure Frame Relay DE discard threshold
 ecn Configure Frame Relay ECN congestion thresholds

R1(config-fr-congest)#thres

interface serial1

   encapsulation frame-relay

   frame-relay intf-type dce

   frame-relay congestion-management

     threshold ecn be 0

     threshold ecn bc 20

     threshold de 40

On Tue, 1 Mar 2005 13:55:34 +0000, kuldip singh <dipa.singh@gmail.com>
wrote:
> Wayne,
> Below is example of how to use the de-list:
>
> The following example specifies that IP packets larger than 512 bytes
> (including the 4-byte Frame Relay Encapsulation) will have the DE bit
> set:
>
> frame-relay de-list 1 protocol ip gt 512
>
>
> On Tue, 1 Mar 2005 13:15:55 +0000, Wayne Bellward <wbellward@gmail.com>
wrote:
> > Hi,
> >
> > This is the first time i've actually posted a question, the archives
> > have always been great in the past. I'm sure someone can help and it
> > would be greatly appreciated.
> >
> > I'd like to set the discard eligible bit for ip on my standard frame
> > relay interface and can't seem to find anything substantial on this or
> > how to confirm it. I have a 2521 as my frame switch and am using frame
> > route commands so I'm not even sure I can confirm any of the FRTS
> > functions i configure.
> >
> > interface Serial0
> > ip address 137.20.101.2 255.255.255.0
> > encapsulation frame-relay
> > ip ospf network broadcast
> > ip ospf priority 0
> > no fair-queue
> > frame-relay interface-dlci 201
> > end
> >
> > Any help or advise on this would be great.
> >
> > Many Thanks,
> >
> > Wayne
> >
> > _______________________________________________________________________
> > Subscription information may be found at:
> > http://www.groupstudy.com/list/CCIELab.html
>
> _______________________________________________________________________
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>

--
Kind Regards,

Bajo



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