From: David Hiers (David_Hiers@adp.com)
Date: Fri May 21 2004 - 19:03:40 GMT-3
If you add sufix of "D", you get this:
http://www.cisco.com/en/US/partner/tech/tk866/tech_protocol_home.html
UNIDIRECTIONAL LINK DETECTION (UDLD)
Introduction
UDLD is a Layer 2 protocol that works with Layer 1 mechanisms to determine the physical status of a link. At Layer 1, autonegotiation takes care of physical signaling and fault detection. UDLD performs tasks that autonegotiation cannot perform, such as detecting the identities of neighbors and shutting down misconnected ports. When you enable both autonegotiation and UDLD, Layer 1 and 2 detections work together to prevent physical and logical unidirectional connections and the malfunctioning of other protocols.
David
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
Carlos G Mendioroz
Sent: Friday, May 21, 2004 11:19 AM
To: Kenneth Wygand
Cc: Church, Chuck; Ahmed Mustafa; ccielab@groupstudy.com
Subject: Re: Quiz Question of the Day 20040520
What is UDL ?
Kenneth Wygand wrote:
> No takers on this one, huh?
>
> Kenneth E. Wygand
> Systems Engineer, Project Services
> CISSP #37102, CCNP, CCDP, ACSP, Cisco IPT Design Specialist, MCP, CNA,
> Network+, A+
> Custom Computer Specialists, Inc.
> "The only unattainable goal is the one not attempted."
> -Anonymous
>
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
> Kenneth Wygand
> Sent: Thursday, May 20, 2004 9:34 PM
> To: Church, Chuck; Ahmed Mustafa; ccielab@groupstudy.com
> Subject: Quiz Question of the Day 20040520
>
> Hello everybody!
>
> Quiz question for the day - this is a snip-it of "debug standby" and
> "debug IP packet" of an HSRP negotiation. What are some possible
> reasons why this is happening? (I know the answer, I broke it on
> purpose). You can tell me technically (i.e. because you are missing a
> command blah blah blah) or theoretically (i.e. the LSA exchange between
> the two OSPF neighbors is not exchanging blah blah blah...). If you
> think you have the right answer, lab it up and see if you can reproduce
> the following output!
>
> Good luck!
> Ken
>
> <snip>
> 15:32:06: SB0:Ethernet0 Hello in 12.12.12.1 Active pri 90 hel 3 hol 10
> ip 12.12.
> 12.254
> 15:32:06: SB0:Ethernet0 Coup out 12.12.12.2 Active pri 95 hel 3 hol 10
> ip 12.12.
> 12.254
> 15:32:06: IP: s=12.12.12.2 (local), d=224.0.0.2 (Ethernet0), len 48,
> sending bro
> ad/multicast
> 15:32:07: SB0:Ethernet0 Hello out 12.12.12.2 Active pri 95 hel 3 hol 10
> ip 12.12
> .12.254
> 15:32:07: IP: s=12.12.12.2 (local), d=224.0.0.2 (Ethernet0), len 48,
> sending bro
> ad/multicast
> 15:32:09: IP: s=12.12.12.1 (Ethernet0), d=224.0.0.2, len 48, rcvd 2
> 15:32:09: SB0:Ethernet0 Hello in 12.12.12.1 Active pri 90 hel 3 hol 10
> ip 12.12.
> 12.254
> 15:32:09: SB0:Ethernet0 Coup out 12.12.12.2 Active pri 95 hel 3 hol 10
> ip 12.12.
> 12.254
> 15:32:09: IP: s=12.12.12.2 (local), d=224.0.0.2 (Ethernet0), len 48,
> sending bro
> ad/multicast
> 15:32:10: SB0:Ethernet0 Hello out 12.12.12.2 Active pri 95 hel 3 hol 10
> ip 12.12
> .12.254
> 15:32:10: IP: s=12.12.12.2 (local), d=224.0.0.2 (Ethernet0), len 48,
> sending bro
> ad/multicast
> 15:32:11: IP: s=12.12.12.1 (Ethernet0), d=224.0.0.2, len 48, rcvd 2
> 15:32:11: SB0:Ethernet0 Hello in 12.12.12.1 Active pri 90 hel 3 hol 10
> ip 12.12.
> 12.254
> 15:32:11: SB0:Ethernet0 Coup out 12.12.12.2 Active pri 95 hel 3 hol 10
> ip 12.12.
> 12.254
> 15:32:11: IP: s=12.12.12.2 (local), d=224.0.0.2 (Ethernet0), len 48,
> sending bro
> ad/multicast
> 15:32:13: SB0:Ethernet0 Hello out 12.12.12.2 Active pri 95 hel 3 hol 10
> ip 12.12
> .12.254
> 15:32:13: IP: s=12.12.12.2 (local), d=224.0.0.2 (Ethernet0), len 48,
> sending bro
> ad/multicast
> 15:32:14: IP: s=12.12.12.1 (Ethernet0), d=224.0.0.2, len 48, rcvd 2
> 15:32:15: SB0:Ethernet0 Hello in 12.12.12.1 Active pri 90 hel 3 hol 10
> ip 12.12.
> 12.254
> 15:32:15: SB0:Ethernet0 Coup out 12.12.12.2 Active pri 95 hel 3 hol 10
> ip 12.12.
> 12.254
> 15:32:15: IP: s=12.12.12.2 (local), d=224.0.0.2 (Ethernet0), len 48,
> sending bro
> ad/multicast
> 15:32:16: SB0:Ethernet0 Hello out 12.12.12.2 Active pri 95 hel 3 hol 10
> ip 12.12
> .12.254
> 15:32:16: IP: s=12.12.12.2 (local), d=224.0.0.2 (Ethernet0), len 48,
> sending bro
> ad/multicast
> 15:32:17: IP: s=12.12.12.1 (Ethernet0), d=224.0.0.2, len 48, rcvd 2
> 15:32:17: SB0:Ethernet0 Hello in 12.12.12.1 Active pri 90 hel 3 hol 10
> ip 12.12.
> 12.254
> 15:32:17: SB0:Ethernet0 Coup out 12.12.12.2 Active pri 95 hel 3 hol 10
> ip 12.12.
> 12.254
> 15:32:17: IP: s=12.12.12.2 (local), d=224.0.0.2 (Ethernet0), len 48,
> sending bro
> ad/multicast
> 15:32:18: SB0:Ethernet0 Hello out 12.12.12.2 Active pri 95 hel 3 hol 10
> ip 12.12
> .12.254
> 15:32:18: IP: s=12.12.12.2 (local), d=224.0.0.2 (Ethernet0), len 48,
> sending bro
> ad/multicast
> 15:32:20: IP: s=12.12.12.1 (Ethernet0), d=224.0.0.2, len 48, rcvd 2
> 15:32:20: SB0:Ethernet0 Hello in 12.12.12.1 Active pri 90 hel 3 hol 10
> ip 12.12.
> 12.254
> 15:32:20: SB0:Ethernet0 Coup out 12.12.12.2 Active pri 95 hel 3 hol 10
> ip 12.12.
> 12.254
> 15:32:20: IP: s=12.12.12.2 (local), d=224.0.0.2 (Ethernet0), len 48,
> sending bro
> ad/multicast
> 15:32:21: SB0:Ethernet0 Hello out 12.12.12.2 Active pri 95 hel 3 hol 10
> ip 12.12
> .12.254
> 15:32:21: IP: s=12.12.12.2 (local), d=224.0.0.2 (Ethernet0), len 48,
> sending bro
> ad/multicast
> 15:32:23: IP: s=12.12.12.1 (Ethernet0), d=224.0.0.2, len 48, rcvd 2
> 15:32:23: SB0:Ethernet0 Hello in 12.12.12.1 Active pri 90 hel 3 hol 10
> ip 12.12.
> 12.254
> 15:32:23: SB0:Ethernet0 Coup out 12.12.12.2 Active pri 95 hel 3 hol 10
> ip 12.12.
> 12.254
> 15:32:23: IP: s=12.12.12.2 (local), d=224.0.0.2 (Ethernet0), len 48,
> sending bro
> ad/multicast
> 15:32:24: SB0:Ethernet0 Hello out 12.12.12.2 Active pri 95 hel 3 hol 10
> ip 12.12
> .12.254
> 15:32:24: IP: s=12.12.12.2 (local), d=224.0.0.2 (Ethernet0), len 48,
> sending bro
> ad/multicast
> 15:32:25: IP: s=12.12.12.1 (Ethernet0), d=224.0.0.2, len 48, rcvd 2
> 15:32:25: SB0:Ethernet0 Hello in 12.12.12.1 Active pri 90 hel 3 hol 10
> ip 12.12.
> 12.254
> 15:32:25: SB0:Ethernet0 Coup out 12.12.12.2 Active pri 95 hel 3 hol 10
> ip 12.12.
> 12.254
> 15:32:25: IP: s=12.12.12.2 (local), d=224.0.0.2 (Ethernet0), len 48,
> sending bro
> ad/multicast
> 15:32:27: SB0:Ethernet0 Hello out 12.12.12.2 Active pri 95 hel 3 hol 10
> ip 12.12
> .12.254
> 15:32:27: IP: s=12.12.12.2 (local), d=224.0.0.2 (Ethernet0), len 48,
> sending bro
> ad/multicast
> 15:32:28: IP: s=12.12.12.1 (Ethernet0), d=224.0.0.2, len 48, rcvd 2
> 15:32:28: SB0:Ethernet0 Hello in 12.12.12.1 Active pri 90 hel 3 hol 10
> ip 12.12.
> 12.254
> 15:32:28: SB0:Ethernet0 Coup out 12.12.12.2 Active pri 95 hel 3 hol 10
> ip 12.12.
> 12.254
> 15:32:28: IP: s=12.12.12.2 (local), d=224.0.0.2 (Ethernet0), len 48,
> sending bro
> ad/multicast
> 15:32:30: SB0:Ethernet0 Hello out 12.12.12.2 Active pri 95 hel 3 hol 10
> ip 12.12
> .12.254
> 15:32:30: IP: s=12.12.12.2 (local), d=224.0.0.2 (Ethernet0), len 48,
> sending bro
> ad/multicast
> 15:32:31: IP: s=12.12.12.1 (Ethernet0), d=224.0.0.2, len 48, rcvd 2
> 15:32:31: SB0:Ethernet0 Hello in 12.12.12.1 Active pri 90 hel 3 hol 10
> ip 12.12.
> 12.254
> 15:32:31: SB0:Ethernet0 Coup out 12.12.12.2 Active pri 95 hel 3 hol 10
> ip 12.12.
> 12.254
> 15:32:31: IP: s=12.12.12.2 (local), d=224.0.0.2 (Ethernet0), len 48,
> sending bro
> ad/multicast
> 15:32:32: SB0:Ethernet0 Hello out 12.12.12.2 Active pri 95 hel 3 hol 10
> ip 12.12
> .12.254
> 15:32:32: IP: s=12.12.12.2 (local), d=224.0.0.2 (Ethernet0), len 48,
> sending bro
> ad/multicast
> 15:32:34: IP: s=12.12.12.1 (Ethernet0), d=224.0.0.2, len 48, rcvd 2
> 15:32:34: SB0:Ethernet0 Hello in 12.12.12.1 Active pri 90 hel 3 hol 10
> ip 12.12.
> 12.254
> 15:32:34: SB0:Ethernet0 Coup out 12.12.12.2 Active pri 95 hel 3 hol 10
> ip 12.12.
> 12.254
> 15:32:34: IP: s=12.12.12.2 (local), d=224.0.0.2 (Ethernet0), len 48,
> sending bro
> ad/multicast
> 15:32:35: SB0:Ethernet0 Hello out 12.12.12.2 Active pri 95 hel 3 hol 10
> ip 12.12
> .12.254
> 15:32:35: IP: s=12.12.12.2 (local), d=224.0.0.2 (Ethernet0), len 48,
> sending bro
> ad/multicast
> 15:32:37: IP: s=12.12.12.1 (Ethernet0), d=224.0.0.2, len 48, rcvd 2
> 15:32:37: SB0:Ethernet0 Hello in 12.12.12.1 Active pri 90 hel 3 hol 10
> ip 12.12.
> 12.254
> 15:32:37: SB0:Ethernet0 Coup out 12.12.12.2 Active pri 95 hel 3 hol 10
> ip 12.12.
> 12.254
> 15:32:37: IP: s=12.12.12.2 (local), d=224.0.0.2 (Ethernet0), len 48,
> sending bro
> ad/multicast
> 15:32:37: SB0:Ethernet0 Hello out 12.12.12.2 Active pri 95 hel 3 hol 10
> ip 12.12
> .12.254
> 15:32:37: IP: s=12.12.12.2 (local), d=224.0.0.2 (Ethernet0), len 48,
> sending bro
> ad/multicast
> 15:32:40: IP: s=12.12.12.1 (Ethernet0), d=224.0.0.2, len 48, rcvd 2
> 15:32:40: SB0:Ethernet0 Hello in 12.12.12.1 Active pri 90 hel 3 hol 10
> ip 12.12.
> 12.254
> 15:32:40: SB0:Ethernet0 Coup out 12.12.12.2 Active pri 95 hel 3 hol 10
> ip 12.12.
> 12.254
> 15:32:40: IP: s=12.12.12.2 (local), d=224.0.0.2 (Ethernet0), len 48,
> sending bro
> ad/multicast
> 15:32:40: SB0:Ethernet0 Hello out 12.12.12.2 Active pri 95 hel 3 hol 10
> ip 12.12
> .12.254
> 15:32:40: IP: s=12.12.12.2 (local), d=224.0.0.2 (Ethernet0), len 48,
> sending bro
> ad/multicast
> 15:32:42: IP: s=12.12.12.1 (Ethernet0), d=224.0.0.2, len 48, rcvd 2
> 15:32:42: SB0:Ethernet0 Hello in 12.12.12.1 Active pri 90 hel 3 hol 10
> ip 12.12.
> 12.254
> 15:32:42: SB0:Ethernet0 Coup out 12.12.12.2 Active pri 95 hel 3 hol 10
> ip 12.12.
> 12.254
> 15:32:42: IP: s=12.12.12.2 (local), d=224.0.0.2 (Ethernet0), len 48,
> sending bro
> ad/multicast
> 15:32:43: SB0:Ethernet0 Hello out 12.12.12.2 Active pri 95 hel 3 hol 10
> ip 12.12
> .12.254
> 15:32:43: IP: s=12.12.12.2 (local), d=224.0.0.2 (Ethernet0), len 48,
> sending bro
> ad/multicastu al
> 15:32:46: IP: s=12.12.12.1 (Ethernet0), d=224.0.0.2, len 48, rcvd 2
> 15:32:46: SB0:Ethernet0 Hello in 12.12.12.1 Active pri 90 hel 3 hol 10
> ip 12.12.
> 12.254
> 15:32:46: SB0:Ethernet0 Coup out 12.12.12.2 Active pri 95 hel 3 hol 10
> ip 12.12.
> 12.254
> 15:32:46: IP: s=12.12.12.2 (local), d=224.0.0.2 (Ethernet0), len 48,
> sending bro
> ad/multicast
> 15:32:46: SB0:Ethernet0 Hello out 12.12.12.2 Active pri 95 hel 3 hol 10
> ip 12.12
> .12.254
> 15:32:46: IP: s=12.12.12.2 (local), d=224.0.0.2 (Ethernet0), len 48,
> sending bro
> al
> All possible debugging has been turned off
> r2#d/multicast
> r2#
> </snip>
>
> -----Original Message-----
> From: nobody@groupstudy.com on behalf of Church, Chuck
> Sent: Sun 5/16/2004 5:05 PM
> To: Ahmed Mustafa; ccielab@groupstudy.com
> Cc:
> Subject: RE: HSRP
>
>
>
> Picture 2 routers, each with a single connection to the LAN
> (where the
> HSRP is run) and a single WAN connection, each to the same
> destination.
> You want router 'A' to be the active HSRP router, because it's
> WAN
> connection is a DS-3. Router 'B' has a T1. So you tell router
> 'A' to
> preempt, because if the DS-3 is up, you want it to assume the
> HSRP
> address right away. On the other hand, if 'B' becomes the
> higher
> priority HSRP router, it's because 'A' lowered it's priority due
> to the
> tracking of the failed DS-3. So you'd want 'B' to be able to
> preempt
> also. Hope that clears it up.
>
>
> Chuck Church
> Lead Design Engineer
> CCIE #8776, MCNE, MCSE
> Wam!Net Government Services - Design & Implementation Team
> 13665 Dulles Technology Dr. Ste 250
> Herndon, VA 20171
> Office: 703-480-2569
> Cell: 703-819-3495
> cchurch@wamnetgov.com
> PGP key:
>
> http://pgp.mit.edu:11371/pks/lookup?op=index&search=cchurch%40wamnetgov.
> com
>
> -----Original Message-----
> From: Ahmed Mustafa [mailto:ahmed.mustafa@sbcglobal.net]
> Sent: Sunday, May 16, 2004 2:44 PM
> To: Church, Chuck
> Subject: Re: HSRP
>
> Is there any practical example you can give. Why would you want
> to
> configure preempt at both ends if tracking is configured.
> ----- Original Message -----
> From: "Church, Chuck" <cchurch@wamnetgov.com>
> To: <EdmondsSG@aol.com>; <james@net-brigade.com>;
> <ahmed.mustafa@sbcglobal.net>; <ccielab@groupstudy.com>
> Sent: Sunday, May 16, 2004 9:41 AM
> Subject: RE: HSRP
>
>
> > That's the exception. If you're using tracking and the
> priority can
> > shift from one side to the other, then you'd want preempt on
> both. I
> > was basing what I said on the example given. Sorry if I
> confused
> > anyone.
> >
> >
> > Chuck Church
> > Lead Design Engineer
> > CCIE #8776, MCNE, MCSE
> > Wam!Net Government Services - Design & Implementation Team
> > 13665 Dulles Technology Dr. Ste 250
> > Herndon, VA 20171
> > Office: 703-480-2569
> > Cell: 703-819-3495
> > cchurch@wamnetgov.com
> > PGP key:
> >
>
> http://pgp.mit.edu:11371/pks/lookup?op=index&search=cchurch%40wamnetgov.
> > com
> >
> >
> >
> >
> > _____
> >
> > From: EdmondsSG@aol.com [mailto:EdmondsSG@aol.com]
> > Sent: Sunday, May 16, 2004 11:59 AM
> > To: Church, Chuck; james@net-brigade.com;
> ahmed.mustafa@sbcglobal.net;
>
> > ccielab@groupstudy.com
> > Subject: Re: HSRP
> >
> >
> > When you use 'standby track' command with HSRP - i belive you
> need
> > prempt on both sides.
> >
> > any comments?
> >
> > Simon
> >
> >
> ______________________________________________________________________
> > _ Please help support GroupStudy by purchasing your study
> materials
> > from:
> > http://shop.groupstudy.com <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
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>
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> _______________________________________________________________________
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> _______________________________________________________________________
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>
-- Carlos G Mendioroz <tron@huapi.ba.ar>
This archive was generated by hypermail 2.1.4 : Wed Jun 02 2004 - 11:12:15 GMT-3