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RE: Demand Circuit revisited posted 08/22/2001
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in line

Mark Salmon
Sr. WAN Engineer Great Lakes Region 
Cingular Wireless
2000 Ameritech Center Drive 3F07B
Hoffman Estates IL 60195
Voice: (847)765-3999
Pager: (847)992-0458
Email: mark.salmon@xxxxxxxxxxxx


-----Original Message-----
From: Peng Li [mailto:lipeng@xxxxxxxxxx]
Sent: Tuesday, August 21, 2001 9:19 PM
To: SALMON, MARK (SBMS); ccielab@xxxxxxxxxxxxxx
Subject: Re: Demand Circuit revisited


Hi,
According to my observation in lab for OSPF DDR, there r three major ways.

1. Physical BAckup interface Dialer0. no passive-inter dialer0, Ospf pakt
should be interesting to bring up the link . u can use DC for this one, some
times later the line down. if there's LSA content change(add/delet
interface), these bring up the link. Data pkt can always follow the correct
RT to dialer0. DC here suppress hello and LSA refesh(every 30min)

OK in real world, may not be allowed in the lab

2. Dialerwatch any route even the route of the S0's link. No passive dialer
0 but you can deny Ospf pkt as interesting pkt. As long as the link up, they
will fast exchange hello and exhange DBD to establish RT to make sure the
data go through. If DC used here, in my lab, the link seems never come down,
I don't know why?

May not be expressly forbidden in the lab, but requirements may prevent
suing this option.  This is the best real world way 

3. Floating. Usually passive dialer0 and Ospf pkt not interesting so that
because we rely on static route at bothe end. not necessary for user of DC.

See #1 comment

Just my little idea. Hope it helps somewhere.
Peng

Lab on Oct. 10

----- Original Message ----- 
From: "SALMON, MARK (SBMS)" <MARK.SALMON@xxxxxxxxxxxx>
To: <ccielab@xxxxxxxxxxxxxx>
Sent: Tuesday, August 21, 2001 8:32 PM
Subject: Demand Circuit revisited


> My dilemma, I have OSPF demand circuit configured on ISDN/Dialer
interfaces.
> I have blocked OSPF multicasts to prevent dialer bouncing.  The 64k
question
> is how to get the demand circuit up so full adjacency is reached while
> preventing OSPF LSPs/LSAs from causing the like to bounce up and down.  On
> both sides redistributed routes or the link to OSPF backbone can cause
> changes in the LSDB to cause flooding over the ISDN line.
>  
> One option I see is to use dialer watch while maintaining the OSPF
multicast
> filtering access list.  Any thoughts?  Anyone have any other ideas (assume
> that snapshot routing for IPX is NOT configured)
>  
> Mark Salmon
> Sr. WAN Engineer Great Lakes Region 
> Cingular Wireless
> 2000 Ameritech Center Drive 3F07B
> Hoffman Estates IL 60195
> Voice: (847)765-3999
> Pager: (847)992-0458
> Email: mark.salmon@xxxxxxxxxxxx
> **Please read:http://www.groupstudy.com/list/posting.html
**Please read:http://www.groupstudy.com/list/posting.html
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