There is an Apple knowledgebase article about this issue.
It is Doc#30922.
Ejay Hire
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]
Sent: Wednesday, May 02, 2001 2:01 PM
To: [EMAIL PROTECTED]
Subject: RE: Spanning Tree Protocol [7:2564]
Believe it or not it's true! We did some test/research on it and we had to
modify some of our login processes to allow the switch to go the STP
process for login, it appeared we were requesting to quickly for the switch.
-----Original Message-----
From: Priscilla Oppenheimer [mailto:[EMAIL PROTECTED]]
Sent: Wednesday, May 02, 2001 1:42 PM
To: [EMAIL PROTECTED]
Subject: Re: Spanning Tree Protocol [7:2564]
If it really takes 15-30 seconds for a switch to forward even when portfast
is enabled, I can see why AppleTalk nodes would hate this. An AppleTalk
node sends messages right away to make sure its own address is unique, and
to find the nearest router, and verify the network number(s) and zone
name(s) for its local network. If the switch isn't forwarding these frames,
the Mac will think it's on a non-routed single network, when it probably
isn't. Worst of all, it might end up with the same address as some other
AppleTalk device.
However...... I find it hard to believe that even with portfast enabled a
switch takes 15-30 seconds to forward traffic. Is that really true?
Priscilla
At 01:22 AM 5/2/01, Jim Gillen wrote:
>I have had plenty of experience with this problem when I updated a token
ring
>network to a fully switched ethernet network.
>
>CISCO has a document on spanning tree and these types of problems.
>
>Enabling portfast still means that it takes 15-30sec for the port on a
switch
>to come up. If you workstation needs to attach to a server (as with the
>Novell
>Client) by sending GetNearestServer (or the like packets) and it needs a
>reply
>to attach during that 15 - 30 sec then it will fail to connect. There may
be
>other problems with the Mac's -???
>
>I would read the document on the CISCO site and then if that doesn't help
let
>us know what is the nature of the problem.
>
>
>
>
>
> >>> "Jason Roysdon" 2/05/01 13:30:21 >>>
>This message has been scanned by MAILSweeper.
>************************************************************
>
>The customer claims that even with portfast enabled the Macs won't function
>due to Spanning tree. Has anyone else heard any such rumors about this?
My
>guess, as you suggested, is that portfast would solve it, but supposedly it
>was tried before disabling spanning tree.
>
>--
>Jason Roysdon, CCNP+Security/CCDP, MCSE, CNA, Network+, A+
>List email: [EMAIL PROTECTED]
>Homepage: http://jason.artoo.net/
>
>
>
>""Leigh Anne Chisholm"" wrote in message
>[EMAIL PROTECTED]">news:[EMAIL PROTECTED]...
> > It's a symptom of the problem I wrote about earlier in this thread.
When
>a
> > MAC becomes active on the network, the computer isn't able to
communicate
>for
> > the first 50 seconds the port detects the end-system is active. The
port
> > begins in blocking mode, then transitions to listening, then learning.
> > Finally, once STP determines that a looped topology hasn't occurred, the
>port
> > is set to forwarding mode. This creates havoc with any end-system that
> > expects to receive over-the-network information within the first 50
>seconds.
> > IP, IPX, AppleTalk - all face the same issue.
> >
> > The simple solution isn't to kill Spanning Tree on all switches - that's
>the
> > "I don't understand the problem so I'll do whatever works and create a
>bigger
> > problem" solution. The real solution is to enable portfast on all
switch
> > ports that have end-systems directly connected. The caveat to this is
to
> > ensure none of the end-systems are capable as acting as a bridge,
>forwarding
> > packets between LAN segments. Enabling portfast essentially disables
> > Spanning
> > Tree on a port - and Spanning Tree is used to ensure a loop-free
>environment.
> >
> >
> > -- Leigh Anne
> >
> > > -----Original Message-----
> > > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]
> > > Sent: April 30, 2001 7:15 PM
> > > To: [EMAIL PROTECTED]
> > > Subject: Re: Spanning Tree Protocol [7:2564]
> > >
> > >
> > > Oh, speaking of AppleTalk. We've got a customer (not mine, but one of
>the
> > > engineers working the account bounced this off me): They claim their
>new
> > > Macs can't access the network if Spanning Tree is enabled. Supposedly
>this
> > > has been verified by Apple and TAC (but we've never had a customer lie
>to
> > > us, so that must be gospel, right. Heh, not). I don't know what
>exactly
> > > the details are, but basically it just doesn't function. The simple
> > > solution is to kill spanning-tree on all the switches, but this is at
a
> > > number of public schools, and I can't wait to hear about a kid
bringing
>in
> > > his Linksys 8 port 10/100 switch and melting their network.
> > >
> > > Anyone else hear such rumors?
> > >
> > > --
> > > Jason Roysdon, CCNP+Security/CCDP, MCSE, CNA, Network+, A+
> > > List email: [EMAIL PROTECTED]
> > > Homepage: http://jason.artoo.net/
> > >
> > >
> > >
> > > ""Priscilla Oppenheimer"" wrote in message
> > > [EMAIL PROTECTED]">news:[EMAIL PROTECTED]...
> > > > At 11:08 AM 4/30/01, Phil Barker wrote:
> > > > >Strongly in favour,
> > > > >
> > > > >A similar problem occurs in an IPX environment.
> > > > >Make sure all Servers/Clients are 'portfast' and
> > > > >switch/switch disable 'portfast'.
> > > >
> > > > A similar problem happens with AppleTalk too. That's what we get for
> > > > expecting switches to replace hubs in a topology. ;-) They were
>designed
> > > as
> > > > bridges and to talk to other bridges. Despite switches being the
> > > > new-fangled thing (well, sort of new), a lot of their functionality
is
> > > > vintage 1980s.
> > > >
> > > > Priscilla
> > > >
> > > >
> > > > >Regards,
> > > > >
> > > > >Phil.
> > > > >--- John Gotti wrote: > Hey
> > > > >all...we are having a problem where workstations
> > > > > > sporatically will not
> > > > > > be able to obtain an IP address from our DHCP
> > > > > > server. After about 4 minutes,
> > > > > > you can perform a manual renew from WINIPCFG and you
> > > > > > get your IP address.
> > > > > > This has baffled me for quite some time and I have
> > > > > > recently been told it is
> > > > > > our Cisco 2924 Switch to blame. The story I was told
> > > > > > is below. I welcome any
> > > > > > comments for or against this opinion. Thank you for
> > > > > > your time.
> > > > > >
> > > > > >
> > > > > > "It appears the problem is connected to the
> > > > > > spanning tree algorithm used
> > > > > > by the CISCO switches. By default, ports on the
> > > > > > switch block as they are
> > > > > > initialised; during this phase the port is in its
> > > > > > spanning tree algorithm
> > > > > > learning and listening state - it is not
> > > > > > forwarding. This is specifically
> > > > > > aimed at ports that will be used to connect to other
> > > > > > switches/routers in a
> > > > > > stack. After a default time (4 mins?) they switch to
> > > > > > the standard forwarding
> > > > > > mode and everything seems normal, the problem is
> > > > > > that you have missed all
> > > > > > the important DHCP broadcast and acknowledgment from
> > > > > > client to DHCP server
> > > > > > during this period.
> > > > > >
> > > > > > You can change this default state by changing the
> > > > > > PORT-FAST setting on
> > > > > > each port. The port is then immediately in the
> > > > > > FORWARDING mode as it is
> > > > > > initialised. By default this setting is DISABLED,
> > > > > > I have ENABLED all
> > > > > > ports except the ports doing the linking to other
> > > > > > switches"
> > > > > >
> > > > >_________________________________________________________________
> > > > > > Get your FREE download of MSN Explorer at
> > > > > > http://explorer.msn.com
> > > > > > FAQ, list archives, and subscription info:
> > > > > > http://www.groupstudy.com/list/cisco.html
> > > > > > Report misconduct and Nondisclosure violations to
> > > > >[EMAIL PROTECTED]
> > > > >
> > > > >
> > > > >____________________________________________________________
> > > > >Do You Yahoo!?
> > > > >Get your free @yahoo.co.uk address at http://mail.yahoo.co.uk
> > > > >or your free @yahoo.ie address at http://mail.yahoo.ie
> > > > >FAQ, list archives, and subscription info:
> > > > >http://www.groupstudy.com/list/cisco.html
> > > > >Report misconduct and Nondisclosure violations to
>[EMAIL PROTECTED]
> > > >
> > > >
> > > > ________________________
> > > >
> > > > Priscilla Oppenheimer
> > > > http://www.priscilla.com
> > > > FAQ, list archives, and subscription info:
> > > http://www.groupstudy.com/list/cisco.html
> > > > Report misconduct and Nondisclosure violations to
[EMAIL PROTECTED]
> > > FAQ, list archives, and subscription info:
> > > http://www.groupstudy.com/list/cisco.html
> > > Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
> > FAQ, list archives, and subscription info:
>http://www.groupstudy.com/list/cisco.html
> > Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
>FAQ, list archives, and subscription info:
>http://www.groupstudy.com/list/cisco.html
>Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
>
>
>**********************************************************************
>This email and any files transmitted with it are confidential and
>intended solely for the use of the individual or entity to whom they
>are addressed. If you have received this email in error please notify
>the system manager.
>
>This footnote also confirms that this email message has been swept by
>MIMEsweeper for the presence of computer viruses.
>
>www.mimesweeper.com
>**********************************************************************
>FAQ, list archives, and subscription info:
>http://www.groupstudy.com/list/cisco.html
>Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
________________________
Priscilla Oppenheimer
http://www.priscilla.com
FAQ, list archives, and subscription info:
http://www.groupstudy.com/list/cisco.html
Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
FAQ, list archives, and subscription info:
http://www.groupstudy.com/list/cisco.html
Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Message Posted at:
http://www.groupstudy.com/form/read.php?f=7&i=2935&t=2564
--------------------------------------------------
FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html
Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
